The Medicinal Landscape of Chrysanthemum indicum L.: Bridging Traditional Wisdom and Modern Evidence

Abstract

Chrysanthemum indicum L. (C. indicum), a perennial herb widely distributed across East Asia, has long been utilised in traditional medicine and as a functional food ingredient. Contemporary research has revealed a chemically diverse phytochemical profile, dominated by flavonoids, phenolic acids, sesquiterpene lactones, essential oils, carotenoids, and polysaccharides, which collectively underpin its broad pharmacological potential. Experimental studies demonstrate that extracts and isolated constituents of C. indicum exert pronounced antioxidant, anti-inflammatory, antimicrobial, hepatoprotective, cardioprotective, and anticancer effects in vitro and in vivo, often through modulation of key molecular pathways such as NF-κB, NLRP3 inflammasomes, AMPK–SIRT1, and Nrf2 signalling. Emerging pharmacokinetic evidence indicates variable oral bioavailability and metabolic transformation of major bioactive compounds, highlighting formulation challenges that may influence therapeutic efficacy. Toxicological studies suggest a generally favourable safety profile at traditionally used doses, although long-term and clinical safety data remain limited. Regulatory positioning varies internationally, with applications spanning traditional herbal preparations, dietary supplements and functional foods. Despite promising preclinical findings, significant challenges persist, including chemical standardisation, bioavailability optimisation, mechanistic clarification and the paucity of well-designed clinical trials. This review critically synthesises current knowledge on the botany, phytochemistry, pharmacological activities, pharmacokinetics, safety considerations and regulatory landscape of C. indicum, identifying key research gaps and outlining future directions to support its evidence-based development as a therapeutic and dietary agent.

1. Introduction

Chrysanthemum indicum L. (C. indicum), historically known as Dendranthema indicum, is a perennial herbaceous species belonging to the genus Chrysanthemum within the Asteraceae family [1,2]. Native to East Asia, this plant has held a revered place in traditional medicine and cultural symbolism for over three millennia. In Chinese, Japanese, and Korean traditions, C. indicum (Juhua) is emblematic of longevity, rejuvenation, and vitality [3]. Its earliest documented use dates back to the Shennong Bencao Jing (Shennong’s Classic of Materia Medica) from the Han dynasty (206 BCE–220 AD), where it was prescribed for ailments like headaches and eye disorders [3].

Through history, C. indicum has been integrated into daily life and ceremonial practice across East Asia. In China, its floral infusions gained popularity during the Tang and Song dynasties; in Japan, it was adopted into seasonal rituals and Kampo medicine; and in Korea, it was incorporated into the national herbal pharmacopoeia [4,5]. These traditions collectively shaped the medicinal use of C. indicum in various ethnopharmacological systems of East Asian medicine.

Within Traditional Chinese Medicine, C. indicum is classified as a cooling herb that clears heat and detoxifies the liver. In Kampo and Korean traditional medicine, it is used to treat conditions such as vertigo, cephalalgia, sore throat, hypertension, and respiratory ailments [6,7]. Common modes of administration include teas, decoctions, topical poultices, and eye washes, reflecting its broad therapeutic applications [3].

In recent decades, the medicinal value of C. indicum has received growing attention from the scientific community. Advances in pharmacognosy have substantiated many traditional uses by revealing a complex phytochemical composition, including flavonoids (e.g., luteolin, quercitrin), terpenoids, phenolic acids, and essential oils [8]. These constituents exhibit a wide array of bioactivities, including antioxidant, anti-inflammatory, hepatoprotective, antimicrobial, and anticancer properties, supporting the plant’s potential role in preventing or managing chronic diseases such as cardiovascular disorders, neurodegeneration, diabetes, and obesity [3].

Mechanistic insights have further elucidated the molecular pathways through which C. indicum exerts its effects. Notably, activation of the adenosine monophosphate (AMP)-activated protein kinase-Sirtuin 1 (AMPK–SIRT1) axis and the Kelch-like ECH-associated protein 1–nuclear factor erythroid 2-related factor 2 (Keap1–Nrf2) antioxidant response pathway has been documented, linking its bioactive molecules to key cellular defence mechanisms [3]. Moreover, beyond conventional pharmacology, C. indicum has shown potential in emerging domains such as green nanotechnology—for instance, in the biosynthesis of silver nanoparticles with antimicrobial activity—and as a functional ingredient in health-promoting foods and nutraceuticals [8,9].

This review explores the medicinal and therapeutic landscape of C. indicum, integrating traditional ethnomedical knowledge with contemporary scientific findings. The following section introduces the botanical and ecological characteristics of the plant, laying the foundation for an in-depth exploration of its phytochemical profile, pharmacological significance and therapeutic relevance. Building on this foundation, this review aims to provide a comprehensive and critical synthesis of the current scientific evidence on the phytochemistry, pharmacological activities, pharmacokinetics, safety, and regulatory status of C. indicum. Specifically, it seeks to: (i) summarise and evaluate the major bioactive constituents; (ii) examine experimental evidence supporting its therapeutic potential; (iii) assess pharmacokinetic and safety considerations relevant to medicinal and nutraceutical applications; and (iv) identify key knowledge gaps and future research priorities.

2. Methodology

This review was developed through a comprehensive literature search focused on C. indicum, covering publications up to 30 November 2025. Searches were conducted across multiple scientific databases, including Scopus and PubMed. This review was conducted as a narrative literature review rather than a formal systematic review. ScienceDirect and Google Scholar were also used to identify supplementary references and for citation tracking. The primary search terms were “Chrysanthemum indicum”, “C. indicum”, and “Dendranthema indicum”, combined using Boolean operators (AND/OR) with keywords such as “health”, “therapeutic effects”, “phytochemistry”, “bioactivities”, and “biological effects” to ensure broad coverage of the plant’s chemical composition and biological potential. The primary database search (Scopus and PubMed) yielded approximately 1040 records prior to duplicate removal. All retrieved citations were exported into reference management software, where overlapping entries across databases were identified and removed. After duplicate removal, approximately 620 unique records remained for screening. Titles and abstracts were screened for relevance. Studies were included if they investigated C. indicum (whole plant, extracts, or isolated compounds) and reported phytochemical characterisation, biological activity, toxicological evaluation, or nutraceutical applications. Only peer-reviewed original research articles and relevant review papers were considered. Studies focusing on other Chrysanthemum species without clear reference to C. indicum, lacking primary data, or not accessible in full text were excluded. Although no formal language restrictions were applied during the search process, the majority of included articles were published in English. Several potentially relevant studies in Chinese, Korean, and Japanese were identified but excluded where full-text translations were unavailable; this is acknowledged as a potential source of language bias. Following full-text evaluation, 144 studies met the inclusion criteria and were incorporated into the final synthesis. Where overlapping datasets were identified, the most comprehensive or recent study was retained to avoid duplication of evidence. Additional references were identified by manually screening the bibliographies of relevant articles, reviews, and meta-analyses. Both original research articles and review papers were considered; the former provided primary data on the phytochemistry and biological activities of C. indicum, while the latter supported background and contextual understanding. Studies were prioritised from the past 20 years to reflect recent advancements. The included studies were synthesised qualitatively, with particular attention to the nature of the tested material (isolated compounds, characterised extracts, or crude preparations) and the strength and relevance of the reported biological evidence. As this was a narrative review, no formal risk-of-bias assessment tool was applied; however, study quality and relevance were critically considered during data interpretation. Pharmacological data were reported using the original units provided in the cited studies to preserve accuracy and avoid misinterpretation, as differences in experimental design, model systems, and reporting formats may limit direct standardisation across studies. All schematic figures were created using Microsoft PowerPoint and Canva to visually summarise and clarify key concepts. Only peer-reviewed sources were used for visual content, while grey literature, conference abstracts, and unpublished materials were excluded.

3. Botanical Profile

C. indicum is an herbaceous perennial belonging to the family Asteraceae. It typically grows up to 1 metre in height and is characterised by ovate to lobed leaves and small capitula bearing bright yellow ray florets (Figure 1), which represent the predominant floral phenotype in wild populations [10]. Despite this, the genus Chrysanthemum is noted for extensive floral colour variation, ranging from white and pink to purple and red, driven largely by differential biosynthesis and accumulation of carotenoids and anthocyanins [11,12,13]. Within C. indicum, naturally occurring variants have been documented, such as C. indicum var. albescens with white florets, and pale pink hybrids, reflecting notable genetic and phenotypic plasticity [12,14].

Figure 1. Chrysanthemum indicum L. (Image @KENPEI, licenced under [CC BY-SA 3.0 Unported]) (https://creativecommons.org/licenses/by-sa/3.0/) (accessed on 1 September 2025).

Morphologically, C. indicum exhibits features useful for species identification and authentication. Pollen morphology is distinct: grains are trizonocolporate with characteristic spines possessing broad, flattened bases marked with grooves and elongated spine lengths averaging 5.9 μm, enabling discrimination from closely related taxa [15]. Vegetative traits include purple–black slender hairs along the stems and oval leaves; when dried, the plant material produces a yellow-brown powder [16]. A key diagnostic feature is the presence of T-shaped trichomes restricted to the adaxial leaf surface, which distinguishes C. indicum from morphologically similar species such as C. morifolium and C. boreale [17].

The broader genus Chrysanthemum encompasses more than 40 recognised species with considerable morphological and ecological diversity [12]. For instance, C. lavandulifolium is characterised by finely dissected leaves and narrow ray florets, while C. zawadskii bears broader foliage and purple-pink flowers [10]. Among cultivated taxa, C. morifolium is the most extensively domesticated, having undergone centuries of selection and hybridisation to yield a remarkable diversity of floral forms (single, double, pompon types) and colours [18,19]. In contrast, wild species such as C. indicum retain simpler floral morphologies but are highly valued for their abundance of bioactive metabolites, which underpin their traditional medicinal applications and growing role in functional food development [10,14].

Beyond morphology, the species is notable for its phytochemical profiles. It contains abundant polyphenolic acids, flavonoids, and sesquiterpene lactones such as alantolactone, compounds associated with its biological activity [20]. Fertilisation practices have been shown to influence both morphological parameters and metabolite composition, with significant increases in polyphenol content reported in leaves and flowers [20].

From a phylogenetic perspective, C. indicum occupies a foundational position within the Chrysanthemum lineage. It is widely regarded as a basal or ancestral species that has contributed significantly to the evolutionary history of cultivated Chrysanthemum [12,14]. Molecular studies and genomic sequencing indicated that C. indicum has played a crucial role in the domestication process through recurrent hybridisation and polyploidisation events.

Introgression of genetic material from wild C. indicum has conferred important agronomic traits, such as stress tolerance, extended floral longevity, and enhanced resistance to pathogens, on modern cultivars [13,21,22]. Phylogenomic analyses further support its close relationship to the ancestral node of current polyploid varieties and underscore its genetic contribution to the cultivated gene pool [22,23].

Ecologically, C. indicum demonstrates wide adaptability and considerable ecological plasticity. It grows in a wide range of environments, including grasslands, forest margins, mountain slopes, riverbanks, and disturbed areas such as roadsides. The species favours moist soils and can tolerate mildly saline conditions, flourishing at elevations from 100 to 2900 metres [24].

This ecological breadth is underpinned by notable cytogenetic diversity: C. indicum occurs in both diploid (2n = 18) and tetraploid (2n = 36) cytotypes, with polyploid forms especially prevalent in central and Southern China [23]. Polyploidy is believed to enhance environmental resilience and has facilitated the species’ role in Chrysanthemum breeding programmes [25]. The primary centre of genetic diversity lies in the Chinese provinces of Anhui, Henan, Hubei, and Jiangxi, which have served as a source for both natural dispersal and human-mediated selection [26].

Together, these botanical, phylogenetic, and ecological characteristics establish C. indicum as a genetically and pharmacologically significant species within the genus. Its ancestral role in Chrysanthemum evolution, combined with its broad ecological adaptability and phytochemical richness, underscores its continuing relevance in both horticultural improvement and medicinal research.

4. Phytochemistry

The phytochemical complexity of C. indicum reflects its longstanding therapeutic relevance and underpins many of its reported pharmacological effects. The species contains a broad array of bioactive secondary metabolites, including flavonoids, phenolic acids, terpenoids, essential oils, carotenoids, and polysaccharides (Figure 2) [12]. These compounds contribute to its documented antioxidant, anti-inflammatory, antimicrobial, and immunomodulatory activities, supporting both its traditional medicinal use and its growing value as a functional food and nutraceutical [27,28].

Figure 2. Major phytochemical constituents of C. indicum.

4.1. Flavonoids

Flavonoids constitute one of the most pharmacologically important classes of secondary metabolites in C. indicum. These polyphenols share a C6–C3–C6 backbone [29,30] and are subdivided into flavonols, flavones, flavanones, flavan-3-ols, isoflavones, and anthocyanins (Figure 3) [30]. Structural modifications such as hydroxylation, glycosylation, and methylation influence polarity, solubility, and bioactivity, thereby affecting pharmacokinetics and therapeutic potential [31,32]. Given their moderate to high polarity, particularly in glycosylated forms, flavonoids are most efficiently extracted using an aqueous alcohol mix [33,34].

Figure 3. Chemical structures of major phytochemical classes found in C. indicum, including flavonoids (e.g., quercetin, catechin, naringenin, apigenin, genistein, cyanidin), hydroxybenzoic acids (e.g., gallic acid, protocatechuic acid, p-hydroxybenzoic acid, syringic acid), hydroxycinnamic acids (e.g., ferulic acid, caffeic acid, p-coumaric acid, sinapic acid), and terpenes (ranging from hemiterpenes to tetraterpenes, including examples such as prenol, nerol, farnesol, phytol, ophiobolin A, β-sitosterol, and β-carotene).

In C. indicum, numerous flavonoids have been identified, including quercitrin, myricetin, luteolin, apigenin, acacetin, and luteolin-7-O-glucoside [35,36]. These compounds have been consistently associated with antioxidant, anti-inflammatory, hepatoprotective, and cytotoxic activities [29,32]. Quantitative studies, however, show wide variability, reflecting differences in plant organ, developmental stage, and extraction methodology.

Specific plant organs and flowering stages influence the flavonoid yield. Wei et al. quantified the total flavonoid content (TFC) of 70% ethanolic extracts of C. indicum aerial parts (leaf, stem, and flower), expressing the results as rutin equivalents (RE)/g extract. Across different growth stages, TFC peaked at the early vegetative stage (G2), with leaves containing the highest levels (265.7 mg RE/g) and stems much lower (86.8 mg RE/g). After declining through mid-stages, TFC rose again at full bloom (G5), with leaves again showing the greatest concentration (215.4 mg RE/g), followed by flowers (143.3 mg RE/g) and stems (49.8 mg RE/g) [27].

Complementary evidence comes from Abalkhail et al., who also reported organ-specific variation in the methanolic extracts of C. indicum, expressing TFC as quercetin equivalents (QE)/g dry extract. Flowers contained significantly higher TFC (95.2 ± 2.3 mg QE/g) compared to leaves (73.2 ± 3.3 mg QE/g), confirming organ-dependent distribution of flavonoids [37]. However, as only a single collection stage was examined, direct stage-based comparisons to Wei et al. are not possible [27]. Conventional hot solvent extraction with 60% ethanol yielded a TFC of 137.29 ± 1.13 mg/g dry flower, based on the sum of individually quantified flavonoids by high-performance liquid chromatography (HPLC) [35].

Uranishi et al. extracted C. indicum leaves with 50% ethanol and quantified flavonoids, reporting TFC values of 2.3–11.4 mg QE/g (dry weight—DW). Antioxidant potency showed only a moderate correlation to TFC (R² = 0.42). Chromatographic profiling identified acacetin, acacetin 7-O-glucoside, and acacetin 7-O-malonylglucoside as the principal leaf flavonoids, underscoring organ-specific chemistry relative to flower glycosides [24].

Further insights come from fractionation studies. Luyen et al. extracted flowers with methanol under reflux, and then partitioned the crude into dichloromethane, ethyl acetate, and aqueous fractions. Further, 9.27 ± 0.97 mg QE/g dry residue (DR) was reported for the crude extract, with marked enrichment in the ethyl acetate fraction (63.49 ± 3.32 mg QE/g DR) and a more modest content in the aqueous fraction (12.47 ± 0.58 mg QE/g DR) [38]. In contrast, little flavonoid was detected in the dichloromethane fraction, consistent with the greater polarity of flavonoids, which preferentially partition into more polar solvents such as ethyl acetate or water. This reveals how post-extraction partitioning can markedly alter apparent flavonoid levels.

Taken together, these findings suggest that both extraction/fractionation techniques and biological variables (organ type, developmental stage) critically shape reported flavonoid yields. A summary of extraction conditions, solvents, and principal flavonoids identified across studies is presented in Table 1, illustrating how methodological and biological variables jointly influence the reported TFC and composition in C. indicum. As shown in Table 1, the predominance of flavonols such as quercetin, luteolin, and apigenin is consistent across most studies, though the absolute TFC varies widely depending on solvent polarity and extraction intensity. Such variability emphasises the need for methodological transparency and careful cross-study interpretation when comparing flavonoid data.

Table 1. Extraction methods, solvents, and key flavonoids identified in C. indicum.

Extraction Method/Solvent	TFC (mg/g DW or Equivalent)	Major Flavonoids Identified	Ref.
70% EtOH (Hot maceration)	74.12 ± 1.85–173.29 ± 4.33 (RE/g extract)	Rutin, quercetin, luteolin, apigenin	[27]
MeOH (Maceration)	73.2 ± 3.3–95.2 ± 2.3 (QE/g DR)	Not specified	[37]
60% EtOH (Hot extraction)	137.29 ± 1.13 (mg/g DW)	Quercitrin, myricetin, luteolin-7-glucoside, quercetin glycosides	[35]
50% EtOH (Sonication + maceration)	2.3–11.4 (QE/g DW)	Acacetin, acacetin-7-O-glucoside, acacetin-7-O-malonylglucoside	[24]
Reflux MeOH extraction and fractionation (EtOAc, H2O)	9.27 ± 0.97 (QE/g DR)	Quercetin, luteolin, isorhamnetin-3-O-glucoside	[38]
	63.49 ± 3.32 (QE/g DR)	Quercetin-type flavonols enriched
	12.47 ± 0.58 (QE/g DR)	Glycosides present

DR = dry residue of the fraction/extract; DW = dry weight of plant material; EtOAc = ethyl acetate; EtOH = ethanol; FW = fresh weight of plant material; MeOH = methanol; QE = quercetin equivalent; RE = rutin equivalent; TFC = total flavonoid content.

4.2. Phenolic Acids

Phenolic acids form another important phytochemical group in C. indicum, particularly hydroxybenzoic acids (e.g., gallic acid) and hydroxycinnamic acids (e.g., caffeic, chlorogenic, and dicaffeoylquinic acids) (Figure 3), with the latter subgroup predominating in floral and leaf tissues [12,39]. These compounds, characterised by hydroxylated aromatic structures, contribute significantly to the plant’s antioxidant and anti-inflammatory potential. Given their hydrophilicity, phenolic acids are generally extracted using aqueous ethanol or methanol, with quantification achieved through spectrophotometry, HPLC or liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS)/ultra-performance liquid chromatography coupled with MS/MS (UPLC-MS/MS) [12,35,40].

Chlorogenic acid is the most consistently reported phenolic marker, found across flowers, leaves, and aerial tissues. For example, leaves at full bloom (G5) extracted with 70% ethanol contained 9.62 ± 0.14 mg/g chlorogenic acid, within a total phenolic content (TPC) of 16.82 ± 0.25 mg gallic acid equivalent (GAE)/g [27]. In contrast, the UAE with 70% ethanol and 2% acetic acid flowers yielded a TPC of 12.7 ± 0.8 mg GAE/g. HPLC-MS identified several phenolic acids, with prenyl-dimethoxy-caffeoyl-p-coumaric acid (0.89 ± 0.06 mg/g) as the dominant constituent, alongside coumaroyloleuropein (0.42 ± 0.03 mg/g), and gallic acid (0.31 ± 0.02 mg/g) [39].

Further evidence comes from fractionation and isolation work on C. indicum flowers. Luyen et al. extracted the dried material by refluxing with methanol, and subsequently partitioned the crude methanolic extract into dichloromethane, ethyl acetate, and aqueous fractions. The ethyl acetate extract was richest in phenolics (525.84 ± 23.51 mg GAE/g DR), yielding multiple caffeoylquinic acid derivatives, including chlorogenic acid, cynarin, and methylated dicaffeoylquinates [38].

Complementary insights are provided by Uranishi et al., who analysed the ethanolic extracts of C. indicum leaves from 22 habitats in Kochi Prefecture (Japan). Chlorogenic acid (0.3–3.3% DW) and dicaffeoylquinic acid isomers (0.6–7.5% DW) predominated, with antioxidant activity correlating positively with 1,5- and 3,5-dicaffeoylquinic acid content [24].

Similarly, Cao et al. found that ray florets contained higher concentrations of phenolic acids than disc florets, suggesting intra-floral variation can significantly shape bioactive profiles [40]. Such discrepancies underscore the influence of tissue type and extraction method on yield.

Sequential methanolic extractions analysed by UPLC confirmed chlorogenic acid as the predominant phenolic acid across tissues. Reported levels in C. indicum flowers ranged from 0.14 to 0.39 g/100 g, while leaves contained higher concentrations (0.36–2.55 g/100 g), and stems showed intermediate values (0.13–0.55 g/100 g). Corresponding TPC varied from 0.31 to 6.78 g GAE/100 g among C. indicum samples, with higher values generally correlating with stronger antioxidant activity (DPPH assay). These data highlight the tissue-specific enrichment of phenolic acids in C. indicum, particularly in the leaves [41]. Representative phenolic compounds, extraction methods, and total phenolic contents reported for C. indicum are summarised in Table 2.

Table 2. Representative phenolic compounds, extraction methods, and TPC in C. indicum.

Extraction Method/Solvent	Plant Part	Key Phenolic Compounds (mg/g DW)	TPC (mg GAE/g DW)	Ref.
70% EtOH (hot maceration)	Leaves (full bloom G5)	Chlorogenic acid (9.62 ± 0.14)	16.82 ± 0.25	[27]
70% EtOH + 2% acetic acid (UAE)	Flowers	Gallic acid (0.31 ± 0.02) Coumaroyloleuropein (0.42 ± 0.03) Prenyl-dimethoxy-caffeoyl-p-coumaric acid (0.89 ± 0.06)	12.7 ± 0.8	[39]
MeOH (Reflux + fractionation)	Flowers	Chlorogenic acid, Cynarin	68.6 ± 0.6 525.8 ± 23.5 38.6 ± 0.6	[38]
50% EtOH (Sonication + maceration)	Leaves	Chlorogenic acid (3–33) 1,5-dicaffeoylquinic acid (6–75)	15.0–64.1	[24]
MeOH (Sequential extraction)	Flowers Stems Leaves	Chlorogenic acid (3.2, 5.2 and 6.9)	3.1–67.8	[41]
Boiling water (Simulated tea-making)/80% MeOH (Ultrasonic extraction)	Ray/Disc florets	Not specified	74.0–123.7	[40]

DW = dried weight of plant material; EtOH = ethanol; GAE = gallic acid equivalent; MeOH = methanol; TPC = total phenolic content; UAE = ultrasound-assisted extraction.

Table 2 highlights chlorogenic acid as a consistent chemotaxonomic marker, present across tissues and extraction types, while other hydroxycinnamic derivatives show marked variation across developmental stages and habitats. The data also reinforce the dominant role of ethyl acetate fractions in concentrating phenolic acids and the strong influence of geography and cultivation conditions on their accumulation.

Geographical origin and environmental factors also influence phenolic profiles. A metabolomics survey of C. indicum conducted by Zou et al. across seven Chinese habitats detected 802 metabolites, with flavonoids and phenylpropanoids varying significantly across regions; multivariate analyses grouped samples by habitat, indicating strong geographic structuring of phenolic composition, though climatic factors were not significantly correlated with metabolite levels [42].

Similarly, in Thailand, cultivation practices using compost and chemical fertilisers altered the bioactive content of C. indicum flowers, with total phenolic content ranging from 8.74 to 10.42 mg GAE/g DW, and fertilised plants exhibiting stronger antioxidant activity than unfertilised controls, underscoring the role of soil management and environment in shaping phenolic accumulation [43].

While HPLC-UV and HPLC-DAD offer reliable quantification, LC-MS or LC-MS/MS provides superior sensitivity, enabling the detection of low-abundance derivatives such as coumaroyloleuropein and gallic acid derivatives [12,39].

Overall, these findings identify chlorogenic acid as a consistent chemotaxonomic marker while demonstrating that tissue type, geography, cultivation practices, and extraction methodology substantially influence the broader phenolic profile.

4.3. Terpenes and Terpenoids

Terpenes and their oxygenated derivatives (terpenoids) represent another major phytochemical class in C. indicum, primarily contributing to its essential oil profile and associated bioactivities [44]. Derived biosynthetically from isoprene units, these compounds are classified by carbon skeleton size: monoterpenes (C10), sesquiterpenes (C15), diterpenes (C20), and triterpenes (C30) [6,45] (Figure 3). In C. indicum, monoterpenes and sesquiterpenes are the most abundant, particularly in flowers and leaves, whereas triterpenoids are less abundant but pharmacologically relevant [8,28].

Gas chromatography coupled with mass spectrometry (GC-MS) analysis of C. indicum flower extracts detected 63 volatiles, with terpenoids forming a major fraction; the dominant sesquiterpene was germacrene D (6.15%), while the principal monoterpene was eucalyptol (1,8-cineole, 4.94%) [35].

Developmental stage further shapes terpenoid output. Zhu et al. profiled C. indicum var. aromaticum across three flower stages using headspace solid-phase microextraction coupled with GC-MS (HS-SPME-GC-MS), identifying 370 volatiles (34.82% terpenoids). Sesquiterpenes predominated in early flower buds, whereas monoterpenes such as linalool increased in blooming flowers. Transcriptome analysis revealed stage-specific expression of terpene synthases (TPS14, GERD), consistent with dynamic emission patterns [46].

Drying conditions significantly alter composition: camphor remained abundant in freeze-dried samples (35.2%), whereas shade-drying yielded higher borneol (28.3%). These shifts suggest enzymatic and oxidative transformations between camphor and borneol, highlighting the need for consistent sample preparation in terpene profiling [47].

Genetic and cytogenetic factors also modulate terpenoid profiles. Feng et al. showed with GC-MS that diploid C. indicum accumulated relatively more monoterpenes, whereas tetraploids were enriched in sesquiterpenes, indicating polyploidy as a driver of metabolic shifts in terpene biosynthesis with implications for chemotaxonomy and breeding [45].

More detailed terpene synthase (TPS) functional analyses confirm ploidy-driven shifts. Yuan et al. identified 938 volatile organic compounds and cloned seven TPS genes in C. indicum var. aromaticum. Enzyme assays showed multifunctional TPS-a proteins producing α-terpineol, β-bisabolene, and (E)-β-farnesene, while a TPS-b enzyme specifically generated β-myrcene and ocimenes. Tetraploid plants accumulated higher proportions of floral terpenoids, whereas diploids exhibited stronger woody notes, highlighting TPS diversification as a molecular basis for ploidy-dependent aroma divergence [48].

Tissue specificity is evident: Zhou et al. found β-farnesene dominated root volatiles (~70% of total, ~25.2% in flower buds), while α-pinene (18.8%) and camphor (~10%) were abundant in flower buds. Petasitene, a newly characterised sesquiterpene, was localised only in roots, whereas β-caryophyllene was more broadly distributed across aerial organs [28].

Comparisons across Chrysanthemum-related species reveal both shared volatiles and distinct chemotypes. Guo et al. analysed essential oils from five wild taxa, including C. indicum, C. nankingense, C. lavandulifolium, C. vestitum, and O. taihangensis, identifying common terpenoids such as camphor, α-pinene, and 1,8-cineole, but with markedly different concentrations [49].

Complementing this, Mohammad and Zahari reported that while C. morifolium oils were richer in β-caryophyllene, C. indicum displayed greater antimicrobial efficacy, likely linked to higher camphor and cineole content. These interspecific differences underscore the functional implications of both phytochemical diversity across species and the importance of detailed profiling in evaluating therapeutic potential.

Collectively, these studies emphasise the complex interplay between developmental stage, genetic background, and processing conditions in shaping the volatile terpenoid profile of C. indicum. A detailed summary of terpenoid composition under varying extraction and plant conditions is provided in Table 3, offering a comparative perspective on key monoterpenes and sesquiterpenes across different analytical methodologies. As shown, germacrene D, camphor, and 1,8-cineole consistently dominate the essential oil profile of C. indicum, whereas monoterpene–sesquiterpene ratios vary according to developmental stage, drying conditions, and ploidy level. These results reinforce the chemotaxonomic value of terpenoids within Chrysanthemum species and their influence on aroma and biological activity.

Table 3. Terpenoid profiles of C. indicum under different extraction and plant material conditions.

Sample Type/Condition	Extraction/Analysis Method	Key Terpenoids Identified	Key Observations	Ref.
Fresh flower	SDE, GC-MS	Germacrene D (6.15%) Eucalyptol (4.94%)	Terpenoids (including cineole and camphor) - major fraction of 63 volatiles	[35]
Developmental stages (buds → bloom)	HS-SPME, GC-MS + transcriptome	Linalool, Germacrene D derivatives, Citronellol	Sesquiterpenes dominate buds; monoterpenes increase in bloom; stage-specific TPS expression	[46]
Shade-dried flower	Hydrodistillation, GC-MS	Camphor (28.8%), Borneol (28.3%)	Drying shifts camphor/borneol ratio	[47]
Freeze-dried flower	Hydrodistillation, GC-MS	Camphor (35.2%), Borneol (24.3%)	Drying alters camphor/borneol ratio Enzymatic/oxidative transformations	[47]
Diploid vs. Tetraploid	Hexane, GC-MS	(E)-β-Farnesene (higher in tetraploid stems), Germacrene D (nearly double in tetraploid leaves)	Diploids richer in monoterpenes; tetraploids enriched in sesquiterpenes	[45]
Diploid vs. Tetraploid	GC–E-nose, widely targeted flavour-omics, GC–O/MS, enzyme assays	α-Pinene, Eucalyptol (diploids); o-Cymene, α-Farnesene (tetraploids)	Tetraploids accumulated >20% terpenoids vs. ~4% in diploids; 7 TPS enzymes functionally characterised	[48]
Roots vs. aerial parts	Hexane, GC-MS + transcriptome	β-Farnesene, α-Pinene, Camphor, β-Caryophyllene, Petasitene	Strong tissue specificity; petasitene confined to roots	[28]
Flower (Chrysanthemum spp.)	HS-SPME, GC-MS; Hydrodistillation, GC-MS	Camphor, α-Pinene, 1,8-Cineole, β-Farnesene, β-Caryophyllene	Marked interspecific variation in levels	[49]

GC–E-nose = ultra-fast gas phase electronic nose; GC–O/MS = gas chromatography olfactometry mass spectrometry; HS-SPME = headspace solid-phase microextraction; SDE = successive distillation extraction.

4.4. Carotenoids

Carotenoids are naturally occurring pigments responsible for the vivid yellow, orange, and red colours in many flowering plants, including Chrysanthemum species. Structurally, these tetraterpenoids (C₄₀), synthesised from eight isoprene units, are generally classified into carotenes (hydrocarbons, e.g., β-carotene, lycopene) and xanthophylls (oxygenated derivatives, e.g., lutein, zeaxanthin) [50] (Figure 4). Functionally, carotenoids play both photoprotective and antioxidative roles in plants, while in humans, they provide provitamin A activity (β-carotene) and ocular protection (lutein, zeaxanthin) [51]. In C. indicum, compositional surveys have identified carotenoids as key contributors to yellow pigmentation alongside flavonoids and anthocyanins. Al Sayed confirmed their presence using chromatographic and spectrophotometric methods, estimating a total carotenoid content of 0.37% (w/w) in dried herb material, although without compound-level resolution [52].

Figure 4. Chemical structures of major carotenoids, including carotenes (hydrocarbons; e.g., α-, β-, and γ-carotene, lycopene, torulene) and xanthophylls (oxygenated derivatives; e.g., astaxanthin, zeaxanthin, lutein, β-cryptoxanthin, and torularhodin).

Processing methods strongly affect pigment retention in C. indicum. Li et al. quantified carotenoids in fresh flowers at 9.8 mg/g DW, with levels decreasing after blanching. Infrared-assisted steam blanching best preserved carotenoids (9.05 mg/g), compared with steam (8.25 mg/g) and infrared blanching (7.61 mg/g). The treatment also minimised colour loss and prevented peroxidase activity regeneration during storage. These findings underline the thermolabile nature of carotenoids and demonstrate the importance of optimised blanching in preserving pigment quality in Chrysanthemum flower tea [53].

Environmental stress can also alter carotenoid levels. Nosratabadi et al. exposed C. indicum to increasing soil copper concentrations (0–400 mg/kg) and found carotenoids remained stable up to 200 mg/kg but significantly increased at 400 mg/kg, reaching 3.87 mg/g FW compared with 2.63 mg/g FW in controls. The results suggest carotenoids play a protective role in oxidative stress tolerance in C. indicum, buffering plants against heavy metal toxicity [54].

Carotenoids are also key quality determinants in processed C. indicum tea products. Prabawa et al. studied drying regimes (40–60 °C) for yellow flowers and identified β-carotene, lutein, and α-carotene as the dominant pigments responsible for yellow colouration. Although not quantified, cabinet drying at 60 °C was found to best preserve pigment quality, yielding products with high antioxidant activity (87.67%) and favourable sensory scores. The study emphasises carotenoids as central to both functional and sensory attributes of C. indicum drinks [55].

Carotenoid biosynthesis in plants occurs within plastids via the methylerythritol phosphate pathway, with accumulation influenced by both genetic regulation and processing conditions [56]. In Chrysanthemum, pigment profiling rather than transcriptomics has provided key insights. Lu et al. quantified carotenoids in C. morifolium breeding lines and found lutein and β-carotene as dominant pigments, with total carotenoid content strongly correlated with the b (yellow–blue) colour parameter, confirming that carotenoids underpin yellow floral colouration [57]. In contrast, Din et al. showed that pale or white cultivars express higher levels of carotenoid cleavage dioxygenase 4a (CCD4a), leading to pigment degradation, while yellow cultivars accumulate carotenoids due to lower CCD4a activity. CCD4 homologues are also present in wild species, including C. indicum, indicating that pigment levels reflect a balance between biosynthesis and degradation pathways [58].

Although knowledge of C. indicum carotenoids remains fragmentary, lutein, zeaxanthin, and β-carotene are likely key constituents, consistent with patterns observed in related taxa. Accumulation of these pigments appears to reflect an interaction between genetic background (flower colour, ploidy), developmental stage, environmental stress responses, and post-harvest processing conditions. Such variability has direct implications for both compositional consistency and biological value, given the established roles of carotenoids in oxidative defence and human health. Future work integrating genotype selection, cultivation management, and standardised analytical methodologies will be critical to defining the carotenoid profile of C. indicum and consolidating its position as a reproducible nutraceutical resource.

4.5. Saccharides (Mono- and Polysaccharides)

Saccharides include both monosaccharides and structurally complex polysaccharides, which contribute to the plant’s physicochemical properties and biological activities. Monosaccharides such as glucose, galactose, arabinose, and rhamnose are commonly identified as constituent units, while polysaccharides are structurally diverse macromolecules composed of monosaccharide residues linked via glycosidic bonds [59,60]. In C. indicum, they are typically heteropolysaccharides containing galacturonic acid, glucuronic acid, arabinose, rhamnose, glucose, and galactose in varying ratios [61,62]. These heteropolysaccharides exhibit considerable variation in branching patterns, molecular weight, and functional group modification, which strongly influence solubility, extractability, and biological activity.

Yuan et al. used microwave-assisted extraction (MAE) with ethanol precipitation and dialysis to prepare JHP-2 (purified polysaccharide fraction from C. indicum tea), achieving a yield of 7.3%, total sugars of 84.3%, and a composition rich in galacturonic acid, arabinose, and galactose [63].

Liu et al. focused on polysaccharides from C. indicum branches and leaves. Under the optimal MAE conditions, the yield reached 9.85%. The crude extract was purified by alcohol precipitation, Sevage deproteinisation, and cellulose chromatography, with the fractions showing dose-dependent hydroxyl and superoxide radical scavenging, confirming antioxidant potential from non-floral tissues [64].

Du et al. extracted polysaccharides from C. indicum flowers using hot water extraction (HWE) followed by ethanol precipitation, Sevage treatment, decolourisation, and dialysis. The process yielded 4.71 g (≈2.35%) from 200 g of raw material. The purified polysaccharide had a total sugar content of 97.2% and consisted primarily of rhamnose, arabinose, xylose, mannose, glucose, galactose, and a trace of fructose.

Xiong et al. employed HWE followed by diethylaminoethyl (DEAE)-cellulose and Sephadex G-100 chromatography to isolate four polysaccharide fractions (CIP1–CIP4) from C. indicum flowers, obtaining a crude yield of 28.07% with carbohydrate contents above 90%, and CIP3 characterised by 91.93% total sugars and a molecular weight (MW) of 8.74 × 10³ Da [61].

Chemical modification can further enhance the functionality of C. indicum polysaccharides. Ming et al. phosphorylated a crude extract using the STMP–STPP method, yielding a phosphorylated derivative (pCIPS) with a polysaccharide content of 90.27% and a degree of substitution of 0.317 [65]. The phosphorylation process preserved the primary carbohydrate structure while altering morphology and improving bioactivity.

Li and colleagues extracted polysaccharides from C. indicum flowers using HWE, ethanol precipitation, Sevage deproteinisation, and chromatographic purification, yielding 36.2% with a MW of 5.85 × 10⁴ g/mol. The fraction was composed mainly of galacturonic acid (32.5%), glucose (26.6%), and arabinose (19.4%). Carboxymethylated derivatives (CMCI-1 to CMCI-3) were prepared, with CMCI-3 (DS 0.60) showing a smaller particle size, greater negative charge, and enhanced bioactivity [66]. The structural diversity of C. indicum polysaccharides, including their extraction yields and monosaccharide composition, is summarised in Table 4.

Table 4. Extraction methods, yields, and monosaccharide composition of C. indicum polysaccharides.

Extraction Method	Plant Part	Yield (%DW)/Purity (%)	Main Monosaccharides	Key Notes	Ref.
MAE → EtOH precipitation → dialysis	Flower tea	7.3%/84.3%	GalA, Ara, Gal, Glc, Rha, Man, GlcA, Xyl	JHP-2 fraction	[63]
MAE → EtOH precipitation	Branches and leaves	9.85%	Not Specified	Crude extract	[64]
HWE → EtOH precipitation → Sevage → DEAE-cellulose → Sephadex G-100	Flowers	28.1%/91.9% (CIP3 fraction)	Man, Rha, GlcA, GalA, Glc, Gal, Xyl, Ara, Fuc	CIP1–CIP4 fractions	[61]
HWE → EtOH precipitation → Sevage → phosphorylation (STMP–STPP)	Flowers	~20.8%/97.3% (crude fraction); 90.3% (pCIPS)	Rha, Ara, Xyl, Man, Glc, Gal, Fru	Phosphorylated (pCIPS)	[65]
HWE → EtOH precipitation → Sevage → DEAE + Sephadex G-100 → carboxymethylation	Flowers	36.2%	GalA, Glc, Ara, Gal, Rha, GlcA, Xyl	Carboxymethylated (CMCI-3)	[66]

Ara = arabinose; CIP = Chrysanthemum indicum polysaccharide; DEAE = diethylaminoethyl-cellulose chromatography; EtOH = ethanol; Fru = fructose; Gal = galactose; GalA = galacturonic acid; Glc = glucose; GlcA = glucuronic acid; HWE = hot water extraction; MAE = microwave-assisted extraction; Man = mannose; Rha = rhamnose; Xyl = xylose.

As outlined in Table 4, extraction techniques and purification strategies exert substantial influence on both yield and sugar composition. Microwave-assisted and hot water extractions dominate the literature, with fractions rich in galacturonic acid, glucose, and arabinose. Chemical derivatisation (e.g., phosphorylation, carboxymethylation) further enhances solubility and biological activity, confirming polysaccharides as promising multifunctional biomaterials from C. indicum.

While phenol–sulfuric acid assays are widely used to quantify total polysaccharide content, many studies combined this with additional structural analyses. For instance, monosaccharide profiling via High-Performance Anion-Exchange Chromatography (HPAEC)-Pulsed Amperometric Detection (PAD) or GC-MS was frequently used to determine sugar composition [62,63], while molecular weight determination was performed using gel permeation chromatography or dynamic light scattering [67]. These methods collectively enhance the resolution of polysaccharide characterisation and enable more informed evaluations of structure–function relationships across different fractions.

Purification strategy also contributes to the observed differences. Studies employing ion-exchange chromatography (e.g., DEAE-cellulose) and size-exclusion techniques (e.g., Sephadex G-100) tend to yield more chemically uniform fractions compared to crude ethanol precipitates [61,63].

Chemical derivatisation has been explored to enhance bioactivity. Phosphorylation, for example, improves solubility and has been associated with increased hepatoprotective effects, while maintaining the underlying carbohydrate backbone [65]. Such modifications demonstrate the potential of polysaccharides as versatile functional biomaterials, although structural integrity must be preserved to retain biological relevance.

Overall, these findings illustrate the dynamic and context-dependent nature of C. indicum phytochemistry, shaped by genetic background, developmental stage, environmental conditions, and extraction methodology. This compositional plasticity is particularly evident within the terpenoid fraction, where core constituents such as camphor and 1,8-cineole recur across studies as potential chemical markers, yet their relative abundance varies according to ploidy level, tissue type, and processing conditions. Such variability has important implications for chemotaxonomic interpretation and bioactivity assessment. As discussed in the following sections, appreciating these underlying phytochemical dynamics is essential when interpreting biological effects or designing pharmacologically relevant preparations of C. indicum.

5. Pharmacological Properties

The pharmacological activities of C. indicum have attracted increasing attention in contemporary research, particularly owing to the plant’s longstanding use in traditional East Asian medicine for treating inflammatory, infectious, and immune-related conditions [10,12]. A growing body of preclinical studies supports these traditional claims, revealing a broad range of bioactivities, including antioxidant [27,33], anti-inflammatory [68,69,70], antimicrobial [71], hepatoprotective [60], and immunomodulatory [70] effects. These bioactivities are primarily linked to the plant’s rich and diverse phytochemical content, especially flavonoids, phenolic acids, terpenoids, and polysaccharides, which modulate key signalling pathways implicated in oxidative stress, inflammation, immune regulation, and apoptosis [30]. The following sections provide a critical overview of the experimental evidence underpinning these effects, indicating the mechanistic relevance of C. indicum in modern pharmacology (Figure 5).

Figure 5. Biological properties of C. indicum.

5.1. Antimicrobial Activity

The antimicrobial potential of C. indicum has been demonstrated across a variety of experimental systems, spanning Gram-positive and Gram-negative bacteria and selected fungi. Potency and spectrum are strongly dependent on extraction solvent, formulation (e.g., native extract vs. nanoparticle), phytochemical composition, cultivation/processing conditions, and the microbiological assay employed.

Karnwal assessed ethanolic, methanolic, and aqueous C. indicum flower extracts against seven common foodborne pathogens, including Staphylococcus aureus (S. aureus), Clostridium perfringens (C. perfringens), Escherichia coli (E. coli), Salmonella typhi (S. typhi), Listeria monocytogenes (L. monocytogenes), Bacillus cereus (B. cereus), and Pseudomonas aeruginosa (P. aeruginosa). The aqueous and methanolic extracts exhibited the strongest antibacterial activity, with minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) as low as 3.75% and 1.87% (v/v, respectively, particularly against C. perfringens, L. monocytogenes, and E. coli. The ethanolic extract, by comparison, was less effective (MIC 7.5%, MBC 3.75%) [72]. These findings suggest that polar solvents may extract a broader spectrum of bioactive constituents with antimicrobial potential.

Arokiyaraj et al. took a green-nanotechnology approach using aqueous C. indicum flower extract as the reducing/capping agent to prepare silver nanoparticles (AgNPs; mean diameter ~52.9 nm, range 37.7–71.9 nm). Antibacterial activity of the AgNPs was tested through disc diffusion assay (25 µg/disc) and broth microdilution assay against B. subtilis, S. aureus, S. epidermidis, E. coli, K. pneumoniae, and P. aeruginosa. The AgNPs displayed strong inhibitory activity against K. pneumoniae (zone of inhibition: 19.1 mm; MIC: 6.25 µg/mL), followed by E. coli (zone 13.0 mm; MIC: 12.5 µg/mL) while also affecting S. aureus to a lesser extent (zone 8.3 mm; MIC: 25 µg/mL) and P. aeruginosa (zone 9.6 mm; MIC: 37.5 µg/mL). S. epidermidis showed no inhibition zone but a measurable MIC (25 µg/mL), whereas B. subtilis was effectively resistant at the tested doses (>25 µg/mL). These findings highlight the selective activity of C. indicum—derived AgNPs against Gram-negative pathogens, particularly K. pneumoniae [9].

Manipulation of cultivation conditions can alter bioactivity. Pavasupree and colleagues supplemented in vitro cultures of C. indicum with titanium dioxide nanoparticles (TiO₂, 10–40 mg/L). The aqueous extracts from plants treated with 10 mg/L TiO₂ displayed markedly enhanced antimicrobial activity against S. aureus, E. coli, and Candida albicans (C. albicans), with MIC and MBC < 3.125 mg/mL. Higher TiO₂ concentrations (30–40 mg/L) were less effective, resembling the control group. The enhancement was attributed to increased production of phenolic compounds in the plants following nanoparticle treatment, rather than the presence of TiO₂ in the extracts [73].

Hydrodistilled essential oil from air-dried flowers yielded a distinct antimicrobial profile. Youssef et al. reported moderate activity against Gram-positive bacteria, with MICs of 62.5 µg/mL for B. subtilis, S. agalactiae and S. pyogenes, and slightly higher MICs of 125–250 µg/mL for S. aureus, S. epidermidis, and Staphylococcus capitis (S. capitis). By contrast, Gram-negative bacteria (E. coli, P. fluorescens, S. flexneri and S. typhimurium) and fungi (A. fumigatus, C. albicans, G. candidum, and S. racemosum) were weakly susceptible (MICs ≥ 500 µg/mL). These data indicate that the volatile oil has selective rather than broad-spectrum activity and is generally less potent than many polar extracts or nanoparticle formulations [74].

Polysaccharide chemistry can be modified to produce antimicrobial activity. Li et al. (2025) [66] isolated a water-soluble polysaccharide (CIP) from dried C. indicum flowers (yield 36.2%; MW 5.85 × 10⁴ g/mol). Native CIP was inactive against S. aureus and E. coli, whereas carboxymethylation (CMCI-1/2/3; degree of substitution 0.27–0.60) generated activity: CMCI-3 (degree of substitution ≈ 0.60) produced inhibition zones against S. aureus of 4.6/9.6/11.1 mm at 50/100/200 mg/mL and against E. coli of 4.0/8.4/9.6 mm at the same concentrations; MICs were 2.5 mg/mL (S. aureus) and 5.0 (E. coli) mg/mL. The authors attributed the activity gain to increased anionic charge disrupting bacterial envelopes; importantly, CMCI-3 showed low haemolytic activity and acceptable cytocompatibility in the assays reported [66].

Specific activity against oral anaerobes has also been documented. The essential oil inhibited periodontopathogens, P. gingivalis, P. intermedia and F. nucleatum, with MICs of 0.1–0.2 mg/mL and MBCs of 0.2–0.8 mg/mL (e.g., P. gingivalis 0.1/0.2 mg/mL; F. nucleatum 0.2/0.4 mg/mL). The crude oil was consistently more potent than major individual constituents (camphor, 1,8-cineole, α-pinene; component MICs 0.4–12.8 mg/mL), suggesting intra-mixture synergy; checkerboard assays also indicated synergism with ampicillin or gentamicin (FICI ≤ 0.5), producing up to ≥8-fold reductions in MIC/MBC) for the combinations tested, findings that imply intra-mixture potentiation and potential adjuvant use with antibiotics [71].

Shen and He developed a composite hydrogel (CTS/PVA/Ag/CHR) by reducing silver ions with Chrysanthemum extract within a chitosan–polyvinyl alcohol matrix. In agar diffusion assays, the hydrogel exhibited large inhibition zones against E. coli (32.5 mm), S. aureus (30.5 mm), and P. aeruginosa (34.0 mm). Plate count tests further confirmed strong bactericidal activity, with complete inhibition achieved within 5 h across concentrations tested, and antimicrobial efficacy was maintained for up to 25 days and after ten reuse cycles. Ex vivo application in milk demonstrated delayed spoilage and effective microbial suppression, while cytotoxicity assays indicated acceptable safety at concentrations up to 0.1 mg/mL, with cell viability exceeding 75%. These findings highlight the broad-spectrum antimicrobial activity and stability of the hydrogel, suggesting its potential application in infection control, wound healing, and related biomedical uses; however, further in vivo validation and clinical studies are required to confirm efficacy and safety in practice [75].

A concise overview of the antimicrobial studies on C. indicum, including extract types, key findings, and experimental models, is summarised in Table 5. Collectively, C. indicum exhibits broad-spectrum antimicrobial activity across diverse extract types. However, potency is strongly influenced by solvent, formulation (e.g., carboxymethylated polysaccharides > native; nanoparticle- and hydrogel-based systems > crude extracts), chemotype, and assay conditions, indicating the need for further in vivo validation. Recent work on Chrysanthemum-mediated silver nanoparticle hydrogels demonstrated robust in vitro and ex vivo efficacy, with broad inhibition of Gram-positive and Gram-negative bacteria and suppression of spoilage in food models [75]. While these findings suggest translational relevance for infection control and wound-healing applications, further in vivo animal studies and well-designed clinical trials are needed to establish dose–exposure–response relationships, pharmacokinetics, safety, and therapeutic efficacy in clinically relevant infections.

Table 5. Summary of antimicrobial activity of C. indicum.

Model	Main Bioactive/Extract Type	Key Findings	Conclusion	Refs.
In vitro	Aqueous and MeOH extracts	↓ MIC/MBC (as low as 3.75%/1.87%) vs. C. perfringens, L. monocytogenes, E. coli	Broad-spectrum antibacterial activity	[72]
In vitro	AgNPs synthesised using aqueous extract	↑ Activity vs. K. pneumoniae, E. coli; moderate vs. S. aureus; resistant: B. subtilis, S. epidermidis	Cell wall disruption; nanoparticle-mediated effects	[9]
In vitro	EtOH extract	MIC/MBC < 3.125 mg/mL vs. S. aureus, E. coli, C. albicans	Bioactivity enhancement via TiO2 (LM)	[73]
In vitro	Essential oil (flower heads)	MIC = 62.5 µg/mL vs. B. subtilis, S. agalactiae, S. pyogenes; less effective vs. Gram− bacteria and fungi	Less potent than polar or nano extracts	[74]
In vitro	Essential oil and EtOH extract	Native CIP ≈ inactive → CMCI-3 (DS~0.6) ↑ activity: MIC S. aureus 2.5, E. coli 5 mg/mL; zones 11/9.6 mm @200 mg/mL.	Carboxymethylation ↑ anionic charge → membrane disruption; modest antibacterial; cytocompatible	[66]
In vitro	Essential oil (aerial parts)	MIC: 0.1–0.2 mg/mL, MBC: 0.2–0.8 mg/mL for F. nucleatum, P. gingivalis; whole oil > isolated compounds	Synergistic activity among volatile constituents	[71]
In vitro	Hydrogel formulated using aqueous Chrysanthemum extract	↑ ZI vs. E. coli (32.5 mm), S. aureus (30.5 mm), P. aeruginosa (34.0 mm); 100% inhibition ≤ 5 h; stable 25 d; >80% activity after 10 reuse cycles; cytotoxicity acceptable (>75% @0.1 mg/mL)	Strong, broad-spectrum antibacterial; stable and reusable; promising biomedical application	[75]
Ex vivo	Hydrogel formulated using aqueous Chrysanthemum extract	↓ Spoilage time; effective microbial suppression in milk during storage compared with controls	Potential for food preservation and wound/health applications	[75]

CIP = a water-soluble polysaccharide; MBC = minimum bactericidal concentration; MIC = minimum inhibitory concentration.

5.2. Anti-Inflammatory

Anti-inflammatory effects represent one of the most widely studied pharmacological actions of C. indicum, corroborating its traditional use in treating inflammatory disorders. Multiple in vitro and in vivo studies have demonstrated modulation of pro-inflammatory mediators, suppression of key signalling pathways, and concurrent antioxidant activity.

Kim et al. first reported that the methanol/water extracts of C. indicum flowers inhibited inflammatory mediator production in LPS-stimulated RAW264.7 macrophages. At 62.5–125 µg/mL, the extracts dose-dependently suppressed nitric oxide (NO) release and reduced TNF-α expression, while also downregulating COX-2 protein and prostaglandin E₂ (PGE₂). Extracts from far infrared-dried flowers showed the strongest effects, consistent with their higher phenolic and flavonoid content [69].

Building on this, Luyen et al. demonstrated that flavonoids and quinic acid derivatives isolated from C. indicum flowers suppressed LPS-induced responses in RAW264.7 macrophages. Quercetin showed the greatest inhibition of NO production (46% at 10 µM), while quercetin and quercimetrin both reduced COX-2 and iNOS protein expression. Other flavonoids, including tricin, isorhamnetin-3-O-glucoside, and apigetrin, consistently lowered TNF-α secretion, confirming phenolic compounds as key contributors to the plant’s anti-inflammatory effects [76].

Yu et al. extended this evidence by demonstrating inhibition of inflammasome activation in both cell-based and animal models. In LPS-primed bone marrow-derived macrophages, C. indicum extract (25–100 µg/mL) suppressed NLRP3 and AIM2 inflammasomes, reducing IL-1β and caspase-1 secretion, and blocked ASC speck formation and phosphorylation, thereby preventing pyroptosis without affecting NLRC4. In a monosodium urate (MSU)-induced peritonitis mouse model, the extract significantly lowered IL-1β secretion and neutrophil infiltration. Chemical profiling identified dicaffeoylquinic acid, luteolin, and chlorogenic acid as major active constituents, supporting inflammasome inhibition as a mechanism of action [77].

Although chrysanthemum stems and leaves contain chemical constituents similar to the medicinal flowers, their anti-inflammatory properties and mechanisms remain insufficiently characterised. Li et al. evaluated aqueous and 80% ethanolic extracts of C. indicum stems and leaves in a zebrafish model of dextran sulphate sodium (DSS)-induced inflammatory bowel disease (IBD). Both extract types reduced intestinal damage, downregulated IL-1β, IL-8, and MMP9 expression, and increased superoxide dismutase (SOD) activity, indicating synergistic antioxidant and anti-inflammatory effects [78].

Lee et al. examined a 70% ethanolic flower extract in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear dermatitis. At 200 mg/kg intraperitoneally, the extract significantly reduced ear thickness and weight in both acute and chronic models. It also decreased serum IL-1β and TNF-α, lowered plasma myeloperoxidase activity, and histological analysis showed diminished neutrophil infiltration [79].

Wu et al. confirmed the broad in vivo efficacy of a supercritical CO₂ extract of C. indicum flowers and buds (CISCFE) across multiple models. Oral administration (40–120 mg/kg) significantly inhibited xylene-induced ear oedema, acetic acid-induced vascular permeability, and carrageenan-induced paw oedema, with the highest dose showing comparable effects to indomethacin (10 mg/kg). In a rat cotton pellet granuloma model, CISCFE suppressed granuloma formation. Biochemical assays revealed reduced TNF-α, IL-1β, IL-6, NF-κB, PGE₂, NO, iNOS, and COX-2, along with decreased MPO and MDA, and enhanced antioxidant enzymes (SOD, GPx, GRd), consistent with both anti-inflammatory and antioxidant activity [80].

Cheng et al. evaluated a butanol fraction enriched in flavonoids (CIBF) from the ethanolic extracts of C. indicum buds. Oral dosing at 150 mg/kg significantly inhibited xylene-induced auricle oedema (~35% reduction). In cyclophosphamide-suppressed mice, CIBF (150–300 mg/kg) enhanced DNFB-induced delayed-type hypersensitivity, boosted IgG and IgM antibody production, and increased carbon-clearance indices, showing concurrent anti-inflammatory and immunostimulatory effects [70].

Finally, Yang et al. assessed a water extract of C. indicum flowers in a capsaicin-induced systemic low-grade inflammation mouse model. Oral treatment for three days (7–28 g/kg/day) reduced serum TNF-α by ~55–63% and circulating LPS by ~76–77%, while increasing IL-10. It also restored gut microbiota richness and composition and markedly raised faecal short-chain fatty acids, suggesting that anti-inflammatory efficacy may be mediated through a microbiota–SCFA axis [81].

Across models, C. indicum extracts, specifically flavonoid and polysaccharide-rich fractions, consistently suppress pro-inflammatory mediators (e.g., TNF-α, IL-1β/6) and pathways (NF-κB, MAPK, COX-2), often with concurrent antioxidant effects. Together, the findings, as summarised in Table 6, indicate a dual anti-inflammatory and immunomodulatory action. Key next steps are pharmacodynamic testing in disease-relevant models, dose–response and pharmacokinetics work, and bioavailability-enhancing formulations to support translation.

Table 6. Summary of anti-inflammatory studies on C. indicum.

Model	Extract Type	Key Findings	Mechanism/Pathway	Refs.
In vitro	MeOH/water extract	↓ NO, ↓ iNOS, ↓ COX-2, ↓ PGE2 in LPS-stim. RAW264.7 cells	Inflammatory enzyme suppression	[69]
In vitro	Isolated flavonoids quinic acids	Quercetin ↓ NO (46% @10 µM); quercetin, quercimetrin ↓ COX-2, iNOS; tricin, iso-3-O-glc, apigetrin ↓ TNF-α	Direct suppression of NO, TNF-α, COX-2, iNOS	[76]
In vitro	MeOH extract	↓ IL-1β, ↓ caspase-1 in LPS-primed BMDMs; blocked ASC specks and phosphorylation; ↓ pyroptosis	Inflammasome inhibition (NLRP3, AIM2, ASC)	[77]
In vivo	MeOH extract	↓ IL-1β, ↓ neutrophil infiltration in MSU-peritonitis mice	Inflammasome inhibition (IL-1β axis)	[77]
In vivo	Aqueous and 80% alcohol extract	↓ IL-1β, ↓ IL-8, ↓ MMP9; ↑ SOD in zebrafish DSS-IBD model	Antioxidant enzyme activation	[78]
In vivo	70% EtOH extract	↓ ear thickness and biopsy weight; ↓ serum IL-1β and TNF-α; ↓ plasma MPO; histology showed reduced neutrophil infiltration	↓ pro-inflammatory cytokines and neutrophil activity (MPO). No COX-2/NF-κB/MAPK data reported	[79]
In vivo	CISCFE (flowers/buds)	↓ oedema (xylene, carrageenan); ↓ vascular permeability; ↓ granuloma; ↓ TNF-α, IL-1β, IL-6, NF-κB, PGE2, NO, iNOS, COX-2; ↑ SOD, GPx, GRd	Cytokine suppression + antioxidant enzyme ↑	[80]
In vivo	CIBF	↓ xylene-induced ear oedema (~35%); 150–300 mg/kg ↑ DTH, ↑ antibody generation by splenocytes, ↑ serum IgG/IgM, ↑ carbon-clearance (phagocytosis)	↑ humoral and cellular responses and mononuclear phagocytic function	[70]
In vivo	Aqueous extract	↓ serum TNF-α (≈55–63%) and ↓ LPS (≈76–77%); ↑ IL-10; restored gut-microbiota diversity/composition and ↑ faecal SCFAs (acetic, propionic, butyric).	Microbiota–SCFA modulation with reduced LPS translocation into blood.	[81]

ASC = apoptosis-associated speck-like protein containing a CARD; BMDMs = bone marrow-derived macrophages; CIBF = cistanche induced bioactive flavonoids; CISCFE = cistanche Salsa flavonoids extract; COX-2 = cyclooxygenase-2; DTH = delayed-type hypersensitivity; GRd = glutathione reductase; IBD = inflammatory bowel disease; IL = interleukin; iNOS = inducible nitric oxide synthase; IgG/IgM = immunoglobulin G/immunoglobulin M; LPS = lipopolysaccharide; MMP9 = matrix metalloproteinase-9; MPO = myeloperoxidase; MSU = monosodium urate; NF-κB = nuclear factor kappa B; NO = nitric oxide; PGE₂ = prostaglandin E₂; Phagocytosis = cellular engulfment process; RAW264.7 = murine macrophage cell line; SCFAs = short-chain fatty acids; Splenocytes = spleen-derived immune cells; TNF-α axis = tumour necrosis factor alpha signalling pathway.

In addition to general inflammatory models, several bioactive constituents of C. indicum, particularly flavonoids such as luteolin, apigenin, and linarin, have demonstrated anti-inflammatory effects in disease-relevant experimental systems [82]. These compounds have been reported to modulate key inflammatory mediators involved in chronic inflammatory disorders, including suppression of pro-inflammatory cytokines and inhibition of NF-κB signalling pathways associated with conditions such as rheumatoid arthritis and neuroinflammation [82]. Furthermore, neuroprotective effects linked to attenuation of microglial activation and oxidative stress have also been described [83]. Although direct clinical evidence for C. indicum in specific inflammatory diseases such as psoriasis and neuroinflammatory disorders remains limited, these findings highlight its potential relevance in disease-oriented inflammatory modulation and support the need for further investigation.

5.3. Antioxidant

C. indicum has been widely investigated for its antioxidant properties, owing to its abundance of flavonoids, phenolic acids, and other redox-active phytochemicals. Both in vitro and in vivo studies provide compelling evidence of its ability to neutralise reactive oxygen species (ROS) and enhance endogenous antioxidant defences.

In early in vitro investigations, Debnath et al. employed a wide range of assays, including 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), superoxide and hydroxyl radical scavenging, and DNA protection tests, to demonstrate that C. indicum not only neutralises free radicals but also prevents oxidative damage at the biomolecular level [33]. Wang et al. further supported these findings by linking antioxidant capacity in ethanolic extracts to elevated total phenolic and flavonoid contents, consistent with known structure–activity relationships of plant polyphenols [84].

More recent studies have confirmed and extended these results. Dolongtelide et al. compared antioxidant activity across different solvent fractions (ethanolic, aqueous, and n-hexane), reporting that the n-hexane fraction showed the strongest DPPH scavenging (IC₅₀ = 1.109 µg/mL), followed by ethanolic (1.350 µg/mL), while the aqueous fraction was weaker (7.588 µg/mL) [85]. Fatimawali et al. reported the potent radical scavenging activity of C. indicum ethanolic extracts, with IC₅₀ values of ~1.35 mg/mL for DPPH, 10.4 µg/mL for ABTS, and 26.7 µg/mL for FRAP assays [86].

In vivo studies reinforce these findings and indicate the physiological relevance of C. indicum’s antioxidant effects. Jeong et al. demonstrated that daily administration of hot aqueous extracts (50 and 100 mg/kg) for 7 days protected rats from CCl₄-induced liver injury by reducing serum markers of hepatocellular damage such as glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH), and downregulating hepatic CYP2E1, a key enzyme implicated in oxidative liver damage [87]. Kim et al. further showed that pretreatment with a 70% ethanolic extract of C. indicum (200 mg/kg for 7 days) preserved hippocampal neurons in a Mongolian gerbil model of transient cerebral ischemia. The extract significantly upregulated endogenous antioxidant enzymes (SOD1, SOD2, CAT, GPx), resulting in ~67.5% neuronal survival—demonstrating neuroprotective efficacy under oxidative stress [88].

Luo et al. evaluated a CISCFE in a UV-induced cutaneous squamous cell carcinoma mouse model. Topical application of CISCFE at doses of 0.48 and 1.6 mg/cm² significantly enhanced antioxidant enzyme activities, including SOD and CAT, while reducing malondialdehyde (MDA) and 8-OHdG levels in skin tissue. CISCFE also lowered pro-inflammatory cytokines such as IL-6 and TNF-α, reduced CD11b+ immune cell infiltration, and modulated apoptotic pathways by downregulating cleaved caspase-3 and Bax while upregulating Bcl-2. These results support the antioxidant, anti-inflammatory, and anti-apoptotic properties of CISCFE in the context of UV-induced skin damage [89].

In summary, these studies affirm the strong antioxidant capacity of C. indicum across diverse models and extract types (Table 7). Importantly, the therapeutic relevance extends beyond free radical scavenging, encompassing organ-specific protection and modulation of oxidative signalling pathways. Further standardisation of extract composition and bioactive markers would facilitate clinical translation.

Table 7. Summary of antioxidant activity of C. indicum.

Model	Main Bioactive(s)/Extract Type	Key Findings	Mechanism/Pathway	Refs.
In vitro	Flavonoids, Luteolin, Apigenin	Strong radical scavenging in DPPH/ABTS/FRAP; broad-spectrum activity across redox environments	H-donation, metal chelation	[86]
In vitro	Aqueous vs. EtOH extracts	Higher antioxidant capacity in EtOH extracts; IC50 = 1.34 mg/mL (EtOH) vs. 2.93 mg/mL (water); correlated with TPC/TFC	Assay-based correlation	[84]
In vitro	Polyphenols, DNA-protective compounds	Broad scavenging of ROS (DPPH, ABTS, hydroxyl, superoxide, nitrite); inhibited oxidative DNA damage; non-cytotoxic	Direct ROS scavenging, DNA protection	[33]
In vitro	EtOH, aqueous, n-hexane fractions	IC50: n-hexane 1.11 µg/mL > EtOH 1.35 µg/mL > aqueous 7.59 µg/mL; strong radical scavenging	Fraction-dependent activity	[85]
In vivo	Hot water extract	↓ GOT, GPT, ALP, LDH; ↓ CYP2E1; improved histology; hepatoprotection from CCl4	Enzyme suppression and detoxification, antioxidant protection	[87]
In vivo	CISCFE	↑ SOD, CAT; ↓ MDA, 8-OHdG, IL-6, TNF-α, CD11b+ infiltration; ↓ cleaved caspase-3, Bax; ↑ Bcl-2; reduced skin apoptosis and inflammation	Antioxidant, anti-inflammatory and anti-apoptotic (UV-induced skin model)	[89]
In vivo	70% EtOH extract	↑ SOD1, CAT, GPx; SOD2 elevated under ischemia; ~67.5% CA1 neuronal survival after ischemia	Neuroprotection via antioxidant enzyme ↑	[88]

ALP = alkaline phosphatase; Bax = Bcl-2-associated X protein; Bcl-2 = B-cell lymphoma 2 protein; CAT = catalase; CCl₄ = carbon tetrachloride; CD11b+ = cluster of differentiation 11b positive cells; CISCFE = cistanche Salsa flavonoids extract; CYP2E1 = cytochrome P450 2E1; DPPH = 2,2-diphenyl-1-picrylhydrazyl; DNA = deoxyribonucleic acid; EtOH = ethanol; FRAP = ferric reducing antioxidant power; GPT = glutamate pyruvate transaminase; GOT = glutamate oxaloacetate transaminase; GPx = glutathione peroxidase; IC₅₀ = half maximal inhibitory concentration; LDH = lactate dehydrogenase; MDA = malondialdehyde; ROS = reactive oxygen species; SOD/SOD1/SOD2 = superoxide dismutase isoforms 1 and 2; TFC = total flavonoid content; TPC = total phenolic content; TNF-α = tumour necrosis factor alpha.

5.4. Anti-Obesity

Evidence from cellular and animal models indicates that C. indicum exerts multi-targeted anti-obesity effects by inhibiting adipogenesis and lipogenesis, enhancing lipid oxidation, and dampening metabolic inflammation. In adipocytes, extracts suppress mitotic clonal expansion and downregulate PPARγ/C/EBPα with associated targets (FABP4, FAS, SCD1), while fermented preparations activate Hedgehog signalling (GLI1) to block differentiation. In vivo, oral extracts reduce body weight and adiposity, improve serum lipids and glycaemia, and limit hepatic steatosis alongside increased PPARα activity and lower inflammasome-linked cytokines.

Kim et al. investigated the anti-adipogenic effects of an aqueous extract of C. indicum enriched with phenolics, including 1,3-dicaffeoylquinic acid, chlorogenic acid, and apigenin. At 2 mg/mL, the extract inhibited adipogenesis via G0/G1 cell cycle arrest, suppression of mitotic clonal expansion, and downregulation of cell cycle proteins (cyclin D1, cyclin A1, CDK2). It also reduced triglyceride content and the expression of adipogenic and lipogenic proteins (PPAR-γ, C/EBP-α, FABP4, FAS, SCD-1), with concurrent inhibition of the Akt and ERK1/2 signalling pathways—both of which are closely tied to lipid biosynthesis and insulin sensitivity [90].

Lee et al. assessed methanolic extracts from Compositae species in 3T3-L1 adipocytes; the C. indicum extract reduced lipid accumulation to ~80%, 73% and 53% of control at 10, 50 and 100 μg/mL, respectively, without stimulating lipolysis (free glycerol release ~94–107% of control). At 200 μg/mL, the extract was cytotoxic. These data indicate a clear anti-adipogenic effect of C. indicum in vitro [91].

Most recently, Cho et al. explored the effects of a C. indicum extract and its fermented counterpart (LLF15), prepared using Lactococcus lactis KCTC 3115. In 3T3-L1 adipocytes, treatment with 1 mg/mL LLF15 significantly reduced lipid accumulation and downregulated key adipogenic transcription factors, PPAR-γ and C/EBP-α. LLF15 also activated the Hedgehog (Hh) signalling pathway by enhancing GLI1 expression via PTCH1 inhibition and SMO activation [92]. This dual modulation suggests that C. indicum may influence both early progenitor commitment and late-stage adipocyte differentiation, offering potential for early-intervention strategies in obesity management.

Complementary studies provide strong support for the physiological relevance of these cellular findings. Yu et al. demonstrated that methanolic extracts of C. indicum inhibited activation of the NLRP3 and AIM2 inflammasomes in LPS-primed bone marrow-derived macrophages, suppressing ASC phosphorylation and reducing IL-1β release. In vivo, the extract also attenuated MSU-induced peritonitis by decreasing neutrophil recruitment and IL-1β secretion [77]. As adipose tissue inflammation is a hallmark of insulin resistance, these anti-inflammatory effects likely contribute to improved metabolic homeostasis.

Lee et al. evaluated a viscozyme- and tannase-treated C. indicum extract in a high-fat diet-induced obesity male C57BL/6 mice model. Oral doses of 4, 20, or 100 mg/kg/day reduced body weight gain, epididymal fat, liver lipids, and improved serum profiles, lowering triglycerides, cholesterol, LDL-c, and leptin while elevating HDL-c and adiponectin. Notably, the extract enhanced lipid oxidation via downregulation of PPAR-γ and C/EBP-α, and upregulation of PPAR-α in adipose and liver tissues, supporting its anti-obesity efficacy through modulation of lipid metabolism and adipogenic transcription [93].

Cha et al. further confirmed the anti-obesity activity of an ethanolic extract of C. indicum in HFD-fed mice. Oral administration of the extract (8–200 mg/kg/day) for six weeks significantly reduced body weight, liver weight, and epididymal white adipose tissue (eWAT) mass, accompanied by improvements in serum lipid profiles. At the molecular level, the extract suppressed adipogenic proteins (PPAR-γ, C/EBP-α, and FAS) in adipose tissue and upregulated hepatic PPAR-α, indicating a dual mechanism involving inhibition of lipid accumulation and enhancement of lipid oxidation [94].

Nepali and their colleagues also demonstrated similar results with an ethyl acetate fraction of C. indicum suppressed obesity in high-fat-diet C57BL/6 mice over six weeks (2–50 mg/kg, p.o.), reducing body-weight gain, epididymal fat, and liver mass; micro-CT confirmed lower abdominal fat, and hepatic TG/TC and ALT/AST decreased. Mechanistically, CIEA improved serum lipids, lowered leptin, increased adiponectin, downregulated PPARγ and C/EBPα/β/δ, and upregulated PPARα with AMPK phosphorylation in adipose and liver, indicating inhibited adipogenesis and enhanced lipid oxidation [95].

More recently, Zhou et al. evaluated a buddleoside-rich extract (BUDE) of C. indicum in a rat model of metabolic syndrome induced by a high-fat, high-sugar, and alcohol-rich diet. Oral plant treatment (75 or 150 mg/kg/day) over six weeks significantly improved serum lipid profiles, lowering triglycerides, total cholesterol, LDL-c, and fasting glucose, while elevating HDL-c. Histological analysis showed reduced hepatic and pancreatic fat deposition. The extracts also suppressed the inflammatory markers IL-6, IL-1β, and NF-κB [96]. These findings suggest a dual mechanism involving metabolic correction and immune modulation.

Collectively, these data position C. indicum as a promising adjunct for obesity management via coordinated control of adipocyte differentiation, lipid handling, and metabolic inflammation. Table 8 summarises the anti-obesity evidence across different studies, detailing extract type, key findings and key mechanisms/pathways (PPARγ/α, C/EBPα, AKT/ERK, Hedgehog–GLI1, NF-κB/NLRP3). The table highlights a convergent pattern of reduced adipogenesis/lipogenesis, enhanced lipid oxidation, and attenuated inflammatory signalling. It serves as a quick cross-study reference to prioritise extract chemotypes and mechanistic endpoints for future work.

Table 8. Summary of anti-obesity activity of C. indicum.

Model	Main Bioactive(s)/Extract Type	Key Findings	Mechanism/Pathway	Refs.
In vitro	Aqueous extract	↓ Lipid accumulation; ↓ PPAR-γ, C/EBP-α, FABP4, FAS, SCD-1; G0/G1 arrest	Akt/ERK1/2 inhibition, cell cycle arrest	[90]
In vitro	MeOH extract	↓ lipid accumulation to ~80%, 73%, 53% of control; ↔ lipolysis (free glycerol 94–107% of control); cytotoxic at 200 μg/mL.	Antiadipogenic during differentiation (↓ lipid synthesis/accumulation); no ↑ in lipolysis.	[91]
In vitro	Fermented EtOH extract (LLF15)	↓ Lipid accumulation; ↓ PPAR-γ, C/EBP-α; ↑ GLI1 activity	Hedgehog pathway activation	[92]
In vitro/In vivo	MeOH extract (aerial parts)	↓ IL-1β and caspase-1 secretion; ↓ ASC speck formation/oligomerization; ↓ ASC phosphorylation; ↓ neutrophil recruitment	NLRP3 and AIM2 inflammasome inhibition	[77]
In vivo	Viscozyme- and tannase-treated extract (CIVT)	↓ BW gain, ↓ WAT mass, ↓ TG, LDL-c, ↑ adiponectin	↓ PPAR-γ, ↑ PPAR-α	[93]
In vivo	EtOH extract	↓ BW, ↓ serum lipids; ↑ hepatic PPAR-α	Adipogenesis inhibition, lipid oxidation	[94]
In vivo	EtOAc fraction of 50% EtOH extract	↓ body-weight gain; ↓ WAT and liver mass; ↓ hepatic TG/TC; ↓ leptin; ↑ adiponectin	↓ PPARγ, C/EBPα/β/δ; ↑ AMPK-P; ↑ PPARα	[95]
In vivo	BUDE	↓ Fat deposition (liver/pancreas); ↓ IL-6, IL-1β, NF-κB	Anti-inflammatory lipid regulation	[96]

AMPK-P = phosphorylated AMP-activated protein kinase; Akt = protein kinase B; ASC = apoptosis-associated speck-like protein containing a CARD; AIM2 = absent in melanoma 2; BW = body weight; C/EBP-α/β/δ = CCAAT/enhancer binding proteins alpha/beta/delta; FABP4 = fatty acid binding protein 4; FAS = fatty acid synthase; GLI1 = GLI family zinc finger 1; Hedgehog = hedgehog signalling pathway; IL = interleukin; LDL-c = low-density lipoprotein cholesterol; NF-κB = nuclear factor kappa B; NLRP3 = NOD-, LRR-, and pyrin domain-containing protein 3; PPAR-α/γ = peroxisome proliferator-activated receptor alpha/gamma; SCD-1 = stearoyl-CoA desaturase 1; TG = triglycerides; TC = total cholesterol; WAT = white adipose tissue; ↔ = no change.

5.5. Anti-Diabetic

The antidiabetic potential of C. indicum has been increasingly recognised in recent years, with studies highlighting its ability to modulate multiple aspects of glucose metabolism, insulin signalling, and diabetic complications. Its therapeutic efficacy appears to be mediated by a range of biochemical mechanisms, including enzyme inhibition, anti-glycation activity, oxidative stress reduction, and inflammatory modulation.

Initial mechanistic insight was provided by Yu et al., who demonstrated that the methanolic extracts of C. indicum suppressed NLRP3 and AIM2 inflammasome activation in macrophages, leading to reduced IL-1β secretion and neutrophil infiltration in a monosodium urate-induced peritonitis model. Given the established role of inflammasome activity and IL-1β in obesity-driven insulin resistance, these results indicate that the anti-inflammatory actions of C. indicum may indirectly enhance insulin sensitivity [77].

Building on this, Salah et al. tested aqueous C. indicum leaf extract and its biosynthesised TiO₂ nanoparticles in vitro for digestive enzyme inhibition. Both preparations dose-dependently suppressed α-amylase activity, achieving up to 85% inhibition at 1000 µg/mL—greater than the reference drug metformin at equivalent concentration. Antioxidant and anti-inflammatory effects were also observed, suggesting dual potential for postprandial glucose control and attenuation of oxidative stress [97].

Additional evidence of complication prevention was offered by Yu et al., who showed that the aqueous flower extracts inhibited protein glycation in a human αA-crystallin–fructose model. By suppressing the formation of advanced glycation end-products (AGEs; 43.36% at 50 µg/mL), these extracts may help mitigate microvascular complications of diabetes, such as retinopathy, nephropathy, and neuropathy [98].

Extending from cellular assays to whole-animal models, Wang et al. isolated linarin, a major flavonoid of C. indicum flowers, and confirmed its anti-diabetic efficacy in vitro and in vivo. In HepG2 hepatocytes, linarin enhanced glucose consumption while activating AMPK and ACC phosphorylation and downregulating gluconeogenic enzymes (PEPCK, p-GS). Consistently, oral treatment of MSG-induced insulin-resistant mice with linarin (25–100 mg/kg for 4 weeks) improved insulin and glucose tolerance and reduced plasma triglyceride and cholesterol, validating its action through AMPK-dependent pathways [99].

Placing this in a broader metabolic framework, Lee et al. evaluated DKB114, a polyherbal formulation combining C. indicum flower extract with Cinnamomum cassia (C. cassia) bark. The formulation inhibited xanthine oxidase activity (IC₅₀ = 104.4 µg/mL) and lowered serum uric acid in hyperuricemic rats through downregulation of renal URAT1 and GLUT9 transporters. Since uric acid excess and xanthine oxidase-derived oxidative stress are linked to β-cell dysfunction and insulin resistance, these results imply that C. indicum may also exert anti-diabetic benefits by modulating metabolic comorbidities that exacerbate glucose dysregulation [100].

Finally, Zhou et al. provided a comprehensive evaluation of BUDE in rats with diet-induced metabolic syndrome. The extract administration significantly lowered fasting blood glucose and improved pancreatic β-cell function. Mechanistically, these improvements were linked to enhanced insulin signalling, with upregulation of key proteins involved in glucose transport and metabolic regulation (IRS1, IRS2, GLUT2) [96]. These findings suggest that C. indicum not only improves insulin sensitivity but may also preserve or restore β-cell integrity.

These studies, as summarised in Table 9, establish C. indicum as a promising multi-targeted agent for the management of hyperglycaemia and metabolic syndrome. Its bioactivities span enzymatic inhibition, glycation suppression, oxidative stress reduction, and immune modulation, hallmarks of comprehensive antidiabetic therapy. Nevertheless, clinical validation remains necessary to confirm its efficacy in human populations, clarify pharmacokinetic profiles under diabetic conditions, and ensure long-term safety.

Table 9. Summary of anti-diabetic activity of C. indicum.

Model	Main Bioactive(s)/Extract Type	Key Findings	Mechanism/Pathway	Refs.
In vitro	MeOH extract of aerial flower parts	↓ NLRP3 and AIM2 activation; ↓ IL-1β secretion in BMDMs	Anti-inflammatory via inflammasome inhibition	[77]
In vitro	Aqueous leaf extract and TiO2 nanoparticles	↓ α-amylase activity (85% inhibition @1000 µg/mL, >metformin); strong antioxidant and anti-inflammatory	α-Amylase inhibition; antioxidant/anti-inflammatory	[97]
In vitro	Aqueous flower extract	↓ AGE formation in αA-crystallin–fructose model; ↓ glycoxidation markers	Anti-glycation/anti-glycoxidation	[98].
In vitro	Linarin	↑ Glucose consumption in HepG2; ↑ p-AMPK and p-ACC; ↓ PEPCK and p-GS	AMPK activation; suppression of gluconeogenesis	[99]
In vitro	C. indicum + C. cassia (DKB114)	↓ XOD activity (IC50 = 104.4 µg/mL)	XOD inhibition	[100]
In vivo	Linarin	↓ FBG; improved ITT and OGTT; ↓ TG and CHO in MSG mice; ↑ p-AMPK and p-ACC	AMPK-dependent insulin sensitisation	[99]
In vivo	C. indicum + C. cassia (DKB114)	↓ Serum uric acid; ↑ urinary uric acid; ↓ URAT1 and GLUT9 in kidney	Uric acid lowering via transporter modulation	[100]
In vivo	MeOH extract of aerial flower parts	↓ IL-1β secretion; ↓ neutrophil infiltration in MSU-peritonitis	Anti-inflammatory (↓ NLRP3/AIM2)	[77]
In vivo	BUDE	↓ FBG; improved β-cell morphology/function; ↑ hepatic glycogen; ↑ IRS1/2 and GLUT2; ↓ NF-κB	Insulin signalling modulation; anti-inflammatory	[96]

ACC = acetyl-CoA carboxylase; AGE = advanced glycation end-product; AIM2 = absent in melanoma 2; AMPK = AMP-activated protein kinase; BMDMs = bone marrow-derived macrophages; CHO = cholesterol; FBG = fasting blood glucose; GLUT2 = glucose transporter type 2; GLUT9 = glucose transporter type 9; GS = glycogen synthase; HepG2 = human hepatocellular carcinoma cell line; IL = interleukin; IRS1/2 = insulin receptor substrate 1/2; ITT = insulin tolerance test; MSG = monosodium glutamate (mouse model); MSU = monosodium urate; NF-κB = nuclear factor Kappa B; NLRP3 = NOD-, LRR-, and pyrin domain-containing protein 3; OGTT = oral glucose tolerance test; p-ACC = phosphorylated acetyl-CoA carboxylase; p-AMPK = phosphorylated AMP-activated protein kinase; p-GS = phosphorylated glycogen synthase; PEPCK = phosphoenolpyruvate carboxykinase; TG = triglycerides; URAT1 = urate transporter 1; XOD = xanthine oxidase.

5.6. Anti-Hypertensive

C. indicum has demonstrated promising anti-hypertensive potential through multifaceted mechanisms, including vasodilation, modulation of vascular smooth muscle cell activity, metabolic regulation, and anti-inflammatory effects.

Mechanistic cell-based work has provided insight into the vascular actions of C. indicum flavonoids. Wu et al. showed that commercially sourced luteolin, a major C. indicum flavone, suppressed vascular smooth-muscle cell proliferation and migration in A7r5 and HASMC lines [101]. The mechanism involved inhibition of TGFBR1/Smad2/3 signalling, thereby limiting vascular remodelling processes relevant to hypertension [101].

Complementary ex vivo and endothelial studies have demonstrated direct vasorelaxant properties. Si et al. found that luteolin (10–100 µM) relaxed rat aortic rings pre-contracted with phenylephrine or KCl, with the effect partly attenuated by the eNOS inhibitor L-NAME. In parallel, luteolin increased phosphorylation of eNOS at Ser1177 in rat aorta and enhanced NO production in primary human aortic endothelial cells. These findings indicate that luteolin promotes endothelium-dependent vasorelaxation through NO-mediated pathways, supporting its potential antihypertensive relevance [102].

Another flavone documented in C. indicum, apigenin, has shown similar endothelial effects. Jin et al. reported that 0.5–72 µM apigenin induced concentration-dependent endothelium-dependent relaxation of rat thoracic aortic rings. Under oxidative stress induced by pyrogallol, apigenin restored acetylcholine-mediated relaxation, elevating NO levels and constitutive NOS activity while suppressing superoxide generation and inducible NOS. These results demonstrate that apigenin exerts vasodilatory and endothelial-protective actions directly relevant to antihypertensive mechanisms [103].

Qin et al. examined the Zhenju antihypertensive compound (ZJAHC), which contains C. indicum extract alongside hydrochlorothiazide, clonidine, rutin, and pearl powder. Using Caco-2 cells, in situ intestinal perfusion, and pharmacokinetic studies in rats, they found that co-administration with ZJAHC significantly enhanced hydrochlorothiazide absorption and bioavailability. Compared with HCT alone, the ZJAHC group showed a 2.2-fold higher cumulative intestinal absorption and more than a twofold increase in plasma AUC, suggesting that C. indicum extract and other constituents potentiate antihypertensive efficacy by improving diuretic exposure [104].

Animal studies strengthen the evidence by confirming blood pressure effects in vivo. Lv et al. tested a flavonoid-rich fraction comprising luteolin and buddleoside in spontaneously hypertensive rats. Oral administration reduced blood pressure in a dose-dependent manner, accompanied by increased NO bioavailability and suppression of endothelin-1, while thromboxane B₂ and prostacyclin I₂ remained unchanged [105].

Further in vivo support comes from Wang and their team, where they combined molecular assays and in vivo work in an LFHSH rat model, using C. indicum flower extracts. In vivo, treatment decreased SBP, DBP, MAP, and heart rate, while in vitro assays showed modulation of NF-κB and PI3K–Akt signalling. Molecular docking further suggested direct interactions with renin–angiotensin system targets, including ACE and AT1R [106].

Sun et al. investigated flavonoids from C. morifolium flowers, specifically luteolin and luteoloside compounds, also documented in C. indicum. In hyperlipidaemic rats, these flavonoids lowered total cholesterol, triglycerides, and LDL-cholesterol, increased SOD, CAT, and GSH-Px activity, and reduced malondialdehyde levels (a lipid-peroxidation marker). These changes could secondarily support vascular function and, by extension, antihypertensive potential; however, the study did not measure blood pressure or vascular reactivity [107].

In a study by Zhou et al., rats with diet-induced metabolic syndrome were treated with BUDE. Test results show improved blood pressure, reduced serum and tissue levels of IL-6 and IL-1β and suppressed NF-κB activation in the liver and pancreas. The antihypertensive effects were linked to downregulation of NF-κB activity and pro-inflammatory cytokines IL-6 and IL-1β [96].

Taken together, these studies, summarised in Table 10, support the therapeutic potential of C. indicum as a complementary antihypertensive agent, mediated by convergent vasodilatory, antioxidant, metabolic, and immunomodulatory pathways. Nevertheless, direct in vitro studies on anti-hypertensive activity specifically for C. indicum remain limited, underscoring the need for standardised extract testing and deeper mechanistic work.

Table 10. Summary of anti-hypertensive activity of C. indicum.

Model	Main Bioactive(s)/Extract Type	Key Findings	Mechanism/Pathway	Refs.
In vitro	Luteolin	↓ VSMC proliferation and migration; ↓ MMP-2/9	↓ TGFBR1/Smad2/3 signalling	[101]
Ex vivo/In vivo	Luteolin	Relaxation of PE- and KCl-precontracted aortic rings; L-NAME-sensitive; ↑ eNOS-Ser1177 phosphorylation; ↑ NO in HAECs	eNOS/NO-mediated vasorelaxation	[102]
Ex vivo	Apigenin	↑ Endothelium-dependent relaxation (0.5–72 µM); restored ACh responses under oxidative stress; ↑ NO and constitutive NOS; ↓ superoxide and iNOS	eNOS/NO–cGMP pathway	[103]
In vitro in vivo	Zhenju antihypertensive compound	↑ HCT absorption in Caco-2 and rat intestine; plasma AUC ↑2.1–2.2-fold; ↑antihypertensive potential at lower HCT dose	Herb–drug interaction; P-gp inhibition; ↑ bioavailability	[104]
In vivo	Flavonoid-rich fraction (luteolin and buddleoside)	↓ SBP and DBP in SHR (dose-dependent); ↑ NO; ↓ endothelin-1; TXB2 and PGI2 unchanged	↑ NO production; ↓ vasoconstrictors	[105]
In vitro	Aqueous flower extract	In vitro: NF-κB and PI3K–Akt modulation; docking to ACE and AT1R	↓ Inflammatory cytokines; RAAS interaction	[106]
In vivo	Aqueous flower extract	In LFHSH + alcohol hypertensive rats: ↓ SBP, DBP, MAP, HR; ↓ CRP, TNF-α, IL-6	↓ Inflammatory cytokines; RAAS interaction	[106]
In vivo	luteolin and luteoloside	↓ TC/TG/LDL-C; ↑ SOD/CAT/GSH-Px; ↓ MDA	Antioxidant/metabolic support; no BP/vasoreactivity measured	[107]
In vivo	BUDE	↓ Blood pressure; ↓ IL-6 and IL-1β; ↓ hs-CRP; suppressed NF-κB activation	↓ NF-κB pathway; anti-inflammatory	[96]

ACh = acetylcholine; ACE = angiotensin-converting enzyme; AT1R = angiotensin II type 1 receptor; AUC = area under the curve; BP = blood pressure; Caco-2 = Human Colorectal adenocarcinoma cell line; CAT = catalase; CRP = C-reactive protein; DBP = diastolic blood pressure; eNOS = endothelial nitric oxide synthase; GSH-Px = glutathione peroxidase; HAECs = human aortic endothelial cells; HCT = hydrochlorothiazide; HR = heart rate; hs-CRP = high-sensitivity C-reactive protein; IL = interleukin; iNOS = inducible nitric oxide synthase; LFHSH = low-fat high-sucrose high-Salt; L-NAME = NG-nitroarginine methyl ester; MAP = mean arterial pressure; MDA = malondialdehyde; MMP-2/9 = matrix metalloproteinase-2/9; NF-κB = nuclear factor kappa B; NO = nitric oxide; NOS = nitric oxide synthase; P-gp = P-glycoprotein; PE = phenylephrine; PGI₂ = prostacyclin; PI3K = phosphoinositide 3-kinase; RAAS = renin–angiotensin–aldosterone system; SBP = systolic blood pressure; SHR = spontaneously hypertensive rat; Smad2/3 = SMAD family members 2 and 3; SOD = superoxide dismutase; TGFBR1 = transforming growth factor beta receptor 1; TC = total cholesterol; TG = triglycerides; TXB₂ = thromboxane B₂; VSMC = vascular smooth muscle cell.

5.7. Immunomodulatory

C. indicum has demonstrated immunomodulatory properties by modulating both innate and adaptive immune responses. Evidence from both in vitro and in vivo studies highlights their potential in regulating inflammatory cascades, promoting immune cell activation, and restoring immune homeostasis.

Yu et al. demonstrated that the methanolic extract of C. indicum suppressed activation of the NLRP3 and AIM2 inflammasome in LPS-primed bone marrow-derived macrophages, leading to reduced IL-1β secretion and inhibition of caspase-1 cleavage. Mechanistically, the extract inhibited ASC speck formation and oligomerization, and reduced ASC phosphorylation at Tyr144, thereby interfering with inflammasome assembly [77].

Polysaccharide fractions have also shown potent immunostimulatory effects. Wang et al. reported that polysaccharides stimulated RAW264.7 macrophage proliferation, phagocytosis, and increased cytokine (TNF-α and IFN-γ) and NO production. These effects were dependent on structural differences such as molecular weight and sugar composition. While the study examined polysaccharides from C. morifolium cultivars rather than C. indicum, the findings remain relevant since structural motifs such as glucose-, arabinose-, galactose- and uronic acid-rich backbones are highly conserved across Chrysanthemum species, and comparable immunostimulatory activity has been reported for C. indicum polysaccharides [108].

Using LPS-stimulated RAW264.7 macrophages, the methanol extract of C. indicum var. albescens was observed to suppress NO and PGE2, downregulate iNOS and TNF-α, and block NF-κB nuclear translocation by directly inhibiting AKT1/2; luteolin was a major active component. By tempering the AKT→NF-κB axis that drives cytokine and eicosanoid release, the extract calibrates macrophage output to maintain immune homeostasis—limiting tissue-damaging hyper-inflammation while preserving stimulus-dependent signalling in innate defence [109].

Zhou et al. evaluated a BUDE of C. indicum extract in LPS-challenged RAW264.7 macrophages. BUDE inhibited NF-κB p65 nuclear translocation, reduced p-p65 levels, and significantly lowered IL-1β and IL-6 mRNA expression, as well as secreted IL-1β. BUDE also decreased IL-10 secretion in culture supernatants, indicating a general dampening of cytokine release rather than selective preservation of anti-inflammatory mediators [96]. Kang and colleagues demonstrated that C. indicum extract strongly inhibited Epstein–Barr virus latent membrane protein-1 (LMP1), induced NF-κB activation in lymphoblastoid cell lines. Activity-guided fractionation revealed that the dichloromethane fraction reduced LMP1-driven NF-κB activity by over 60%, blocked IκB kinase (IKK) activation, and markedly decreased lymphoblastoid cell viability, while exerting minimal cytotoxicity on non-NF-κB-dependent cells. Lupeol, a pentacyclic triterpene isolated from this fraction, was identified as one of the active constituents inducing apoptosis and attenuating NF-κB signalling, although with lower potency than the whole fraction—suggesting synergistic interactions between components [110].

C. indicum methanolic extract administration has also been proven to inhibit the activation of the NLRP3 inflammasome in a monosodium urate-induced peritonitis mouse model. Treatment significantly reduced IL-1β levels and neutrophil infiltration in the peritoneal cavity, indicating effective suppression of inflammasome-mediated inflammation [77].

In a proteoglycan-induced ankylosing spondylitis mouse model, C. indicum extract re-balanced immune activation: serum TNF-α, IL-1β and IL-6 decreased, antioxidant enzymes levels increased (SOD, CAT, GSH-Px), and spinal NF-κB p65 fell alongside increases in the Wnt antagonists Dickkopf-related protein 1 (DKK-1) and sclerostin. These changes indicate systemic immunomodulation that tempers inflammatory drive and osteo-immune crosstalk implicated in pathological bone formation [111].

In bleomycin-challenged rats, a supercritical CO₂ flower/bud extract of C. indicum lessened fibrosis and remodelled immune–fibrotic signalling. Treatment reversed increases in α-SMA, vimentin, collagen-I and nuclear β-catenin, and normalised MMP-3/9 with restoration of Tissue Inhibitor of Metalloproteinases-1 (TIMP-1). mRNA, protein expression, histology and hydroxyproline assays corroborated reduced lung injury, consistent with re-tuning Wnt/β-catenin activity and limiting pro-fibrotic inflammatory remodelling [112].

In capsaicin-induced food-related low-grade inflammation, water extract of C. indicum flowers reduced systemic inflammatory tone by lowering serum TNF-α and circulating LPS, while restoring IL-6 and IL-10 towards control. Concomitantly it increased gut α-diversity, enriched Lactobacillus and boosted faecal short-chain fatty acids, indicating mucosal–systemic immune recalibration that constrains endotoxemia. These shifts reflect improved barrier function and lower innate activation [81].

Cheng et al. fractioned ethanolic extract of C. indicum inflorescences sequentially into petroleum ether (CIPEF), ethyl acetate (CIEAF), n-butanol (CIBF), and water (CIWF) fractions. Among these, the butanol fraction (CIBF) exhibited the strongest activity, producing ~35% inhibition of xylene-induced ear oedema—greater than the reference drug naproxen (~21%). In cyclophosphamide-immunosuppressed mice, only CIBF significantly enhanced immune function, restoring splenic antibody generation, serum IgG/IgM titres, delayed-type hypersensitivity responses, and macrophage phagocytosis [70].

Together, these findings, summarised in Table 11, emphasise the capacity of C. indicum to modulate immune responses through diverse mechanisms, offering therapeutic promise in both immune enhancement and suppression of pathological inflammation. Future studies should explore standardised preparations and dosage optimisation for potential clinical application.

Table 11. Summary of immunomodulatory activities of C. indicum.

Model	Main Bioactive(s)/Extract Type	Key Findings	Mechanism/Pathway	Refs.
In vitro	MeOH extract	↓ NLRP3 and AIM2 inflammasome activation; ↓ IL-1β and caspase-1; blocked ASC speck formation	↓ ASC phosphorylation, inflammasome assembly	[77]
In vitro	Polysaccharides	↑ Macrophage proliferation, phagocytosis, NO, TNF-α, IFN-γ production (structure-dependent)	Macrophage stimulation dependent on molecular weight and sugar composition	[108]
In vitro	MeOH extract	↓ NO, PGE2, iNOS and TNF-α mRNA; inhibited NF-κB (p65/p50) nuclear translocation	Direct AKT1/2 kinase inhibition; ↓ IKKα/β and IκBα activation → NF-κB ↓	[109]
In vitro	BUDE	RAW264.7: ↓ NF-κB p65 nuclear translocation and p-p65; ↓ IL-1β, IL-6 and IL-10 mRNA/protein	NF-κB p65 pathway blockade → macrophage inflammatory signalling ↓	[96]
In vitro	70% EtOH extract	Inhibited NF-κB activation; ↓ lymphoblastoid cell viability; lupeol identified as active triterpene	Blocked IKK activation (canonical and non-canonical NF-κB); induced apoptosis in LCLs	[110]
In vivo	MeOH extract	↓ IL-1β secretion and neutrophil infiltration	NLRP3 inhibition, anti-inflammatory action	[77]
In vivo	70% EtOH extract	↓ TNF-α, IL-1β, IL-6; ↑ SOD, CAT, GSH-Px; ↓ spinal NF-κB p65; ↑ DKK-1 and sclerostin; ↑histology	NF-κB activity ↓; Wnt/β-catenin re-tuned; osteo-immune crosstalk moderated	[111]
In vivo	Supercritical CO2 extract	↓ lung injury and hydroxyproline; ↓ α-SMA, vimentin, collagen-I; MMP-3/9 normalised; TIMP-1 restored	Wnt/β-catenin signalling re-balanced; inflammatory-fibrotic remodelling constrained	[112]
In vivo	Aqueous flower extract	↓ TNF-α, ↓ circulating LPS; IL-6 and IL-10 restored towards control; ↑ gut α-diversity, ↑ Lactobacillus, ↑ faecal SCFAs	Gut–immune axis modulation: endotoxemia ↓; TLR4 signalling ↓; barrier function ↑; effector balance restored	[81]
In vivo	Butanol fraction (EtOH extract)	↑ Splenic antibody generation, DTH responses, serum IgG/IgM titres; ↑ phagocytic activity	B-cell activation, cellular and humoral ↑	[70]

α-SMA = alpha smooth muscle actin; AKT1/2 = protein kinase B isoforms 1 and 2; AIM2 = absent in melanoma 2; ASC = apoptosis-associated speck-like protein containing a CARD; B-cell = B lymphocyte; CAT = catalase; COL-I = collagen type I; DKK-1 = dickkopf-1; DTH = delayed-type hypersensitivity; GSH-Px = glutathione peroxidase; IFN-γ = interferon gamma; IgG/IgM = immunoglobulin G/immunoglobulin M; IKKα/β = IκB kinase alpha/beta; IL = interleukin; iNOS = inducible nitric oxide synthase; IκBα = inhibitor of NF-κB alpha; LCLs = lymphoblastoid cell lines; LPS = lipopolysaccharide; MMP-3/9 = matrix metalloproteinase-3/9; NF-κB = nuclear factor kappa B; NLRP3 = NOD-, LRR-, and pyrin domain-containing protein 3; NO = nitric oxide; PGE₂ = prostaglandin E₂; p65/p50 = NF-κB subunits; RAW264.7 = murine macrophage cell line; SCFAs = short-chain fatty acids; SOD = superoxide dismutase; TIMP-1 = tissue inhibitor of metalloproteinases-1; TLR4 = toll-like receptor 4; TNF-α = tumour necrosis factor alpha; TrkB = tropomyosin receptor kinase B; Wnt = wingless/integrated (signalling pathway); β-catenin = beta catenin.

5.8. Neuroprotection

Growing evidence indicates that C. indicum exerts significant neuroprotective effects through antioxidative, anti-inflammatory, and anti-apoptotic mechanisms, suggesting therapeutic potential in neurodegenerative and cerebrovascular disorders.

In vitro studies have elucidated several mechanisms. Jeong et al. reported that ethanolic extract of C. indicum protected murine hippocampal HT22 cells from H₂O₂-induced cytotoxicity. Pre-treatment with 50–200 μg/mL increased viability, reduced LDH release, and lowered ROS and mitochondrial depolarisation. Protection involved activation of TrkB/Akt/CREB/BDNF and Nrf2 antioxidant pathways, supporting both trophic and oxidative stress–mitigating mechanisms [113].

Similarly, essential oils derived from C. indicum flowers (at concentrations of 1.56–6.25 μg/mL) increased PC-12 cell viability and reduced ROS generation under oxidative stress. Thymol, a major constituent, showed potent concentration-dependent neuroprotection [114]. Parallel evidence from human SH-SY5Y dopaminergic cells showed that C. indicum extract attenuated MPP⁺-induced ROS production, stabilised the Bax/Bcl-2 ratio, and prevented PARP cleavage, thereby preventing apoptotic cell death. In BV-2 microglial cells, the extract reduced iNOS and COX-2 expression, inhibited NF-κB p65 translocation, and suppressed inflammatory cytokines such as TNF-α, IL-1β, and IL-6 [115].

Chun et al. tested several traditional stroke remedies, including C. indicum extract. In SK-N-SH neuroblastoma cells, aqueous extract increased viability by 20–27% under oxygen–glucose deprivation, showing in vitro protection. However, in a gerbil two-vessel occlusion model, it failed to preserve hippocampal CA1 neurons, unlike other plant extracts, suggesting context-dependent efficacy [116].

Yoo et al. investigated the effects of C. indicum extract (200 mg/kg orally, 7 days) in gerbil transient cerebral ischemia. In the vehicle-ischemia group, CA1 neuronal survival was reduced by ~92%, with only ~8% of NeuN-positive neurons remaining relative to sham. By contrast, pretreatment with C. indicum preserved 63.6% of CA1 neurons, demonstrating robust protection. This effect was accompanied by reduced astrocytic (GFAP⁺) and microglial (Iba-1⁺) activation and maintenance of IL-2 and IL-13 expression in hippocampal tissue, indicating an anti-inflammatory mechanism underlying the neuroprotection [83].

Kim et al. demonstrated that oral pretreatment with C. indicum extract (200 mg/kg for 7 days) provided marked neuroprotection in gerbil global ischemia. In the vehicle-ischemia group, only ~9% of hippocampal CA1 neurons survived at 5 days post-ischemia, whereas pretreatment with C. indicum preserved ~68% of NeuN-positive neurons relative to sham controls. This protection was accompanied by significantly higher SOD1, CAT, and GPx immunoreactivity in CA1 pyramidal neurons, with partial increases in SOD2, indicating that reinforcement of endogenous antioxidant defences contributed to neuronal survival [88].

Bungihan and Balonquita assessed C. indicum extract in hypercholesterolemic rats. Treatment significantly lowered serum total cholesterol, triglycerides, and LDL while elevating HDL. Immunoglobulin levels and lymphocyte proliferation were also reduced [117]. Although no neuronal or behavioural measures were performed, the lipid-lowering and immunomodulatory effects are indirectly relevant since systemic hypercholesterolemia and chronic immune activation are recognised risk factors for cerebrovascular and neurodegenerative disease [118,119].

Yu et al. demonstrated that systemic administration of C. indicum extract suppressed NLRP3 and AIM2 inflammasome activation, reducing IL-1β and IL-6 levels and neutrophil infiltration in a peritonitis model. Although conducted outside the CNS, these inflammasome-related mechanisms are relevant to neuroinflammation and may have implications for neurodegenerative disease [77].

As outlined in Table 12, the neuroprotective effects of C. indicum are well supported across cellular and animal models, though clinical validation remains lacking. Future research should prioritise translational studies to assess its efficacy in human neurological conditions. Cumulative evidence from preclinical studies supports a diverse pharmacological profile for C. indicum, spanning anti-inflammatory, antimicrobial, antioxidant, antihypertensive, immunomodulatory, and neuroprotective activities. These effects appear to be mediated through well-defined molecular targets, including modulation of inflammatory cytokines, inhibition of oxidative stress, regulation of immune responses, and protection against vascular and neuronal injury. The phytochemical complexity, rich in flavonoids, essential oils, polysaccharides, and phenolic compounds, contributes to its pleiotropic effects.

Table 12. Summary of neuroprotective effects of C. indicum.

Model	Main Bioactive(s)/Extract Type	Key Findings	Mechanism/Pathway	Refs.
In vitro	EtOH extract	↑ HT22 viability, ↓ ROS and mitochondrial depolarisation, ↓ LDH leakage under oxidative stress	↑ TrkB/Akt/CREB/BDNF, ↑ Nrf2 antioxidant signalling	[113]
In vitro	Essential oil (thymol)	↑ PC-12 viability, ↓ ROS; thymol dose-dependently prevented oxidative damage	Antioxidant activity, anti-cholinesterase	[114]
In vitro	MeOH extract	↓ MPP+-induced apoptosis, ↓ iNOS/COX-2, ↓ TNF-α, IL-1β, IL-6	Stabilised Bax/Bcl-2, ↓ NF-κB, ↓ PARP cleavage	[115]
In vitro	Aqueous extract	↑ SK-N-SH viability by 20–27% under OGD; no in vivo efficacy observed	Anti-oxidative protection in vitro only	[116]
In vivo	EtOH extract	Preserved ~63.6% CA1 neurons vs. ~8% in controls; ↓ gliosis, maintained IL-2 and IL-13	↓ Astrocytic and microglial activation, cytokine modulation	[83]
In vivo	EtOH extract	Preserved ~68% CA1 neurons vs. ~9% in controls; ↑ SOD1, CAT, GPx; partial ↑ SOD2	Reinforcement of endogenous antioxidant defences	[88]
In vivo	EtOH extract	↓ Total cholesterol, triglycerides, LDL; ↑ HDL; ↓ immunoglobulins; modest effect on lymphocyte proliferation	Systemic lipid-lowering and immune modulation	[117]
In vivo	MeOH extract	↓ IL-1β, IL-6, neutrophil infiltration in MSU peritonitis model	↓ NLRP3/AIM2 inflammasome activation	[77]

Akt = protein kinase B; AIM2 = absent in melanoma 2; Bax = Bcl-2–associated X protein; Bcl-2 = B-cell lymphoma 2; BDNF = brain-derived neurotrophic factor; CA1 = cornu ammonis region 1; CAT = catalase; COX-2 = cyclooxygenase-2; CREB = cAMP response element-binding protein; EtOH = ethanol; GPx = glutathione peroxidase; HDL = high-density lipoprotein; HT22 = hippocampal neuronal cell line; IL = interleukin; iNOS = inducible nitric oxide synthase; LDH = lactate dehydrogenase; LDL = low-density lipoprotein; MPP⁺ = 1-methyl-4-phenylpyridinium; meoh = methanol; MSU = monosodium urate; NF-κB = nuclear factor kappa B; NLRP3 = NOD-, LRR-, and pyrin domain-containing protein 3; Nrf2 = nuclear factor erythroid 2–related factor 2; OGD = oxygen-glucose deprivation; PARP = Poly (ADP-ribose) polymerase; PC-12 = rat pheochromocytoma cell line; ROS = reactive oxygen species; SK-N-SH = human neuroblastoma cell line; SOD1 = superoxide dismutase 1; SOD2 = superoxide dismutase 2; TNF-α = tumour necrosis factor alpha; TrkB = tropomyosin receptor kinase B.

However, despite the robustness of in vitro and animal model data, the absence of clinical trials significantly hampers translational relevance. Standardisation of extract types, bioactive compound profiling, dosage optimisation, and mechanistic validation are crucial for the advancement of C. indicum as a credible therapeutic agent. Until such data become available, its use in evidence-based medicine remains suggestive rather than definitive. Nonetheless, the current body of evidence lays a strong foundation for further investigation into its clinical potential.

6. Nutraceutical Properties

C. indicum has long been consumed in East Asia as a floral infusion, valued not only for its delicate aroma and flavour but also for its integration into traditional wellness practices. Naturally caffeine-free, Chrysanthemum tea offers a soothing alternative to conventional teas and is popular among individuals seeking daily health support [7].

Traditional consumption is increasingly supported by contemporary reviews. Shahrajabian et al. highlighted cardiovascular benefits, including cholesterol regulation and arterial health, which are likely mediated by antioxidant and anti-inflammatory constituents [7,96,100]. The tea is also described as improving eyesight and protecting against cataracts and macular degeneration. Duan et al. summarised in vivo evidence where Chrysanthemum extracts alleviated visual fatigue in animal models [7,120], consistent with long-standing use of Chrysanthemum tea for eye health and vision improvement [6,7].

Broader reviews substantiate these claims. Janarny et al. placed C. indicum among edible flowers with strong antioxidant potential [121], highlighting its flavonoids (quercetin, myricetin) and phenolic acids as contributors to, and radical scavenging [33], anti-inflammatory [78,80] and anticancer [89] activities. Liu, Ahmed, and Long [122] documented Chrysanthemum as a central component of the liáng chá (cooling herbal tea) tradition in southern China, consumed for clearing heat, detoxification, improving vision, and promoting systemic wellness [3,6,7].

Quan et al. provided modern validation by developing a Puerariae Flos, Chrysanthemum beverage [123], demonstrating optimal extraction conditions for high flavonoid content and reporting hepatoprotective and antioxidant potential [78,85]. Several studies have reinforced the functional food positioning of Chrysanthemum teas, noting consistent identification of flavonoids (apigenin, luteolin, quercetin), phenolic acids, and volatile oils across species [6,35,38,124].

In addition to polyphenols and volatile oils, Chrysanthemum also contains carotenoids and ascorbic acid that contribute to vitamin activity. Carotenoids such as β-carotene and lutein act as precursors of vitamin A, while ascorbic acid provides vitamin C activity [55]. The health-supportive role of these vitamins, in synergy with plant phenolics, has been widely recognised in the nutraceutical literature [86,87,125]. Shahrajabian et al. further noted Chrysanthemum tea as a source of vitamins A and C, associated with immune-supportive effects [7].

Together, these sources support the classification of C. indicum tea as a functional beverage. Its phytochemicals, flavonoids, phenolic acids, carotenoids, vitamins, and essential oils act synergistically to deliver antioxidant, hepatoprotective, ocular, and cardiovascular benefits, validating its role in integrative health approaches and modern phytomedicine research.

In addition to its pharmacological and nutraceutical properties, C. indicum has attracted interest for industrial and therapeutic applications, as reflected by several patent filings. Representative patents covering extraction methods, functional compositions, and natural pigment preparations are summarised in Table 13, highlighting its potential use in food, medicinal, and cosmetic products. Notably, one international patent application filed under the World Intellectual Property Organisation Patent Cooperation Treaty (WIPO-PCT) indicates growing global interest in the development and commercialisation of C. indicum-derived products.

Table 13. Representative Patents Related to C. indicum.

Patent No.	Year	Country	Title	Claimed Application	Ref.
CN101112407A	2007	China	Application of wild Chrysanthemum ethanol extract in the preparation of drugs for preventing and treating alcoholic liver disease	Prevention and treatment of alcoholic liver disease; safe, non-toxic, with pharmacological effects and various oral forms	[126]
CN102746702A	2012	China	Extraction method of four-season Chrysanthemum pigment	Natural pigment extraction for beverages, candies, jams, cakes; simple process and low-cost colouration	[127]
US20140127369A1	2014	USA	Composition containing C. indicum L. extract for preventing discolouration	Anti-browning agent for fruits and vegetables via inhibition of polyphenol oxidase	[128]
CN104711121A	2015	China	Method for extracting C. indicum L. essential oil in ultrasonic-assisted solvent-free microwave extraction manner	Efficient extraction of essential oil with short time, low temperature, and improved aroma and yield	[129]
WO2016105035A3	2016	WIPO (PCT)	Anti-gout composition containing mixture extract of C. indicum L. and Cinnamomum cassia as active ingredient	Reduction in uric acid levels and xanthine oxidase inhibition; safe natural anti-gout composition	[130]
KR20210085334A	2021	South Korea	Composition for preventing, ameliorating or treating atopic dermatitis comprising C. indicum L. oil extract	Prevention or treatment of atopy by inhibiting IgE production and reducing mast cell infiltration in animal models	[131]

7. Pharmacokinetics and Bioavailability Considerations

Pharmacokinetic evaluation of C. indicum indicates that absorption, metabolism, and systemic availability vary considerably depending on the chemical class of the constituent. Flavonoids, terpenoids, polysaccharides, and neolignans exhibit distinct pharmacokinetic behaviours influenced by molecular size, polarity, and metabolic susceptibility.

Flavonoids such as linarin, rutin, luteolin, and apigenin are absorbed following oral administration but undergo extensive phase II metabolism, resulting predominantly in glucuronidated and sulphated conjugates in circulation [132,133,134,135]. For example, pharmacokinetic analysis in rats demonstrated that linarin and related flavonoids are rapidly absorbed and subsequently metabolised into conjugated derivatives and smaller phenolic compounds such as acacetin and apigenin [132,135]. These findings are consistent with general flavonoid pharmacokinetics, where systemic exposure to free aglycones is limited due to rapid metabolic conversion [133,134]. Co-administration with absorption enhancers such as piperine has been shown to increase linarin bioavailability, suggesting that intestinal transport and first-pass metabolism are key determinants of systemic exposure [136].

Volatile terpenoids, including borneol and related compounds present in C. indicum, exhibit more rapid absorption and clearance due to their low molecular weight and lipophilicity. Experimental studies have shown that borneol is rapidly detectable in plasma following oral administration and is largely eliminated within several hours, reflecting efficient absorption and systemic distribution [137]. Similar compounds such as camphor and 1,8-cineole undergo oxidative metabolism primarily mediated by cytochrome P450 enzymes, including CYP2A6 and CYP3A4, supporting the role of hepatic metabolism in their clearance.

In contrast, polysaccharides derived from C. indicum show minimal systemic absorption due to their large molecular size and hydrophilic nature. Instead, these compounds exert biological effects indirectly through modulation of gut microbiota and intestinal barrier function. Experimental studies have demonstrated that Chrysanthemum polysaccharides can alter microbial composition, enhance tight junction protein expression, and reduce circulating inflammatory mediators, suggesting systemic benefits mediated through gut–organ interactions rather than direct systemic bioavailability [60].

For neolignan constituents such as fargesin, in silico pharmacokinetic modelling predicts favourable gastrointestinal absorption but limited penetration across the blood–brain barrier [138]. However, experimental pharmacokinetic validation remains limited, highlighting the need for further investigation.

Overall, available evidence suggests that while many low-molecular-weight constituents of C. indicum are absorbed and distributed systemically, their bioavailability is influenced by rapid metabolic transformation and elimination. In contrast, macromolecular components such as polysaccharides exert biological effects primarily through local gastrointestinal mechanisms. Despite these advances, comprehensive pharmacokinetic data, particularly in humans, remain limited. Further in vivo and clinical studies are required to better understand systemic exposure, metabolic pathways, and potential implications for therapeutic and nutraceutical applications.

8. Safety, Toxicity, and Adverse Effects

The safety profile of C. indicum has been evaluated in several preclinical studies, which generally indicate low toxicity and good tolerability. Acute toxicity studies have reported no mortality or severe clinical toxicity in animal models administered doses up to 2000 mg/kg of C. indicum extracts or essential oil preparations. Genotoxicity assessments, including bacterial reverse mutation and micronucleus assays, have also shown no evidence of mutagenic effects, supporting its genomic safety [139].

Sub-acute toxicity studies have similarly demonstrated favourable safety outcomes. Polyherbal formulations containing C. indicum administered at therapeutic dose ranges did not produce significant adverse effects in animal models, although mild biochemical changes were observed at higher doses. The median lethal dose (LD₅₀) was estimated to be greater than 2000 mg/kg, indicating relatively low acute toxicity [140].

In disease models, C. indicum extracts have shown organ-protective effects without evidence of treatment-related toxicity. For example, administration of ethanol extracts in a thioacetamide-induced hepatofibrosis model significantly improved biochemical and histological markers of liver injury while demonstrating good tolerability [141]. These findings suggest potential therapeutic benefits alongside a favourable safety profile in experimental conditions.

Nevertheless, adverse reactions have been reported, particularly among individuals sensitised to plants of the Asteraceae family. Occupational exposure studies have documented allergic reactions, including rhinitis, conjunctivitis, asthma, and dermatitis, associated with Chrysanthemum pollen and plant materials [142,143]. These effects are attributed primarily to allergenic proteins and sesquiterpene lactones and highlight the need for caution in susceptible individuals.

Safety considerations related to product quality have also been evaluated. Analysis of Chrysanthemum tea preparations has shown that pesticide exposure from consumption is generally below levels of toxicological concern, with risk quotient values indicating minimal health risk under typical consumption conditions [144]. However, variability in cultivation, harvesting, and processing conditions may influence contaminant levels and product safety.

Overall, current evidence supports the relatively safe use of C. indicum in traditional medicine and nutraceutical applications. However, most available safety data are derived from preclinical studies, and well-controlled clinical studies are needed to confirm long-term safety, potential herb–drug interactions, and safety in sensitive populations. Continued quality control and standardisation will be essential to ensure consistent safety and efficacy of C. indicum-derived products.

9. Regulatory Status

Regulatory information for C. indicum varies depending on jurisdiction and intended use. The plant is widely recognised in traditional medicine systems, particularly in East Asia, where it has been used for centuries and is documented in traditional medical texts and pharmacopeial references, including those of China, Korea, and Japan [3,4,5,6,7]. In these regions, Chrysanthemum flowers are commonly used as herbal medicines and functional foods.

Outside of traditional medicine systems, C. indicum is generally marketed as a herbal product, nutraceutical ingredient, or dietary supplement, rather than as an approved pharmaceutical drug. At present, specific regulatory approvals for therapeutic indications by major regulatory agencies such as the U.S. Food and Drug Administration (FDA), European Medicines Agency (EMA), or Health Canada have not been widely reported in the scientific literature [14]. Instead, regulatory oversight typically focuses on product safety, quality control, and appropriate labelling rather than formal drug approval.

Some studies have highlighted the importance of improving regulatory standardisation and quality control for Chrysanthemum-derived products, particularly given variations in cultivation, processing, and chemical composition [14,77]. Overall, while C. indicum has well-established traditional and commercial use, further regulatory harmonisation and clinical evaluation will be important to support its development as an evidence-based nutraceutical or therapeutic agent.

10. Conclusions

C. indicum represents a botanically, chemically, and pharmacologically rich medicinal plant whose traditional applications are increasingly supported by modern scientific investigation. Its diverse phytochemical repertoire, particularly flavonoids, phenolic acids, terpenoids, carotenoids, and structurally complex polysaccharides, supports a wide range of biological activities, most notably antioxidant, anti-inflammatory, antimicrobial, and immunomodulatory effects. Mechanistic studies implicate the regulation of oxidative stress, inflammatory signalling, and immune pathways as central to its therapeutic potential.

Emerging pharmacokinetic evidence highlights variable oral bioavailability and metabolic transformation of key bioactive constituents, while existing toxicological data suggest a generally favourable safety profile at traditionally used doses. Regulatory classification varies across jurisdictions, reflecting its dual positioning as a traditional herbal medicine, dietary supplement, and functional food ingredient. Nevertheless, the translation of preclinical findings into clinical and commercial applications remains constrained by variability in phytochemical composition, lack of standardised extraction protocols, incomplete pharmacokinetic characterisation, insufficient bioavailability data, and the scarcity of well-designed human studies.

Future research should prioritise the establishment of quality control frameworks, harmonised processing strategies, comprehensive pharmacokinetic and long-term safety evaluations, and rigorously controlled clinical studies to substantiate health claims. Addressing these gaps will be essential for realising the full nutraceutical and therapeutic potential of C. indicum and for advancing its integration into evidence-based health products.