Search Results (81)

The plant microbiome plays a crucial role in the health of the tea plant, while Bacillus thuringiensis (Bt) is widely utilized as a biological pesticide in tea gardens, promoting sustainable agricultural practices. However, the effects of Bt spraying on tea quality and the structure and function of the phyllosphere microbiome remain unclear. This study evaluated the effects of Bt spraying on tea quality, microbiome composition, diversity, and potential functions using tea leaf quality measurements and high-throughput sequencing of the 16S/ITS rDNA genes. Results showed that spraying Bt1 significantly increased the contents of free amino acids (by 15.27%), flavonoids (by 18.00%), soluble sugars (by 62.55%), and key compounds such as epicatechin gallate (by 10.50%), gallocatechin gallate (by 122.52%), and epigallocatechin gallate (by 61.29%), leading to improved leaf quality. Co-occurrence network analysis indicated that the community structure of both epiphytic and endophytic microbes became more complex after Bt treatment. The abundance of beneficial bacteria, such as Novosphingobium, Methylobacterium, and Sphingomonas, increased significantly, while pathogenic fungi like Aspergillus and Phyllosticta decreased. Functional prediction indicated enhanced amino acid metabolism, secondary metabolism, and carbohydrate metabolism, particularly the biosynthesis of flavonoids, which supports disease resistance and boosts secondary metabolite levels. Furthermore, Bt application reduced pathogenic fungi, enhancing the tea plant’s resistance to diseases. Overall, foliar spraying of Bt can positively alter the phyllosphere microbiome by enriching beneficial bacteria and improving metabolic functions, ultimately enhancing tea plant resistance and quality, and providing a scientific basis for sustainable pest management in tea cultivation. Full article

Camellia ptilophylla Chang (C. ptilophylla), a unique low-caffeine tea species, is valued for its bioactive properties, especially antioxidant and anticancer activities, due to its distinct phytochemical profile. However, its precise constituents and mechanisms remain poorly understood. This study employs an integrated approach combining chromatographic separation, bioinformatic analysis, and cellular assays to systematically investigate the antioxidant and anticancer properties of C. ptilophylla and elucidate its underlying molecular mechanisms. Quantitative analysis revealed that in addition to trans-catechins, the unique polyphenolic compounds, gallocatechin-3,5-di-O-gallate (GC-3,5-diGA) and 1,2,4,6-tetra-O-galloyl-β-D-glucopyranose (1,2,4,6-GA-glc), constituted significant proportions of C. ptilophylla extracts, with concentrations of 10.25 ± 0.29% and 6.60 ± 0.14%, respectively. Monomeric activity assessment demonstrated that both GC-3,5-diGA and 1,2,4,6-GA-glc exhibited pronounced antiproliferative effects against three cancer cell lines including the Lymph Node Carcinoma of the Prostate cell, human colon cancer cell, and human breast cancer cell. Notably, these compounds demonstrated potent antioxidant capacity, with 62.5 μM of GC-3,5-diGA and 15.63 μM of 1,2,4,6-GA-glc protecting against tBHP-induced oxidative stress in NIH3T3 cells comparable to 125 μM of epigallocatechin gallate and gallocatechin gallate in half-maximal inhibitory concentration. Mechanistic studies revealed that these polyphenols modulated antioxidant defenses and reactive oxygen species homeostasis via targets like fibroblast growth factor 2, telomerase reverse transcriptase, matrix metalloproteinase 9, and ATP-binding cassette subfamily G member 2, inducing oxidative stress and mitochondrial apoptosis to inhibit carcinogenesis. These findings enhance our understanding of the bioactive components responsible for the anticancer and antioxidant properties of C. ptilophylla and provide a scientific basis for the development of this dual-purpose plant for food and medicinal applications. Full article

To investigate the flavour evolution mechanism of raw Pu-erh tea (RPT) during storage, the volatile and non-volatile compounds of RPT with different storage years (1–10 years) from the same raw material origin, manufacturer, and storage location in Wenshan Prefecture, Yunnan Province, were systematically analysed by HPLC, HS-SPME-GC-MS, and OAV. The results showed that both cluster analyses based on non-volatile and volatile compounds could classify RPT of different storage years into three ageing cycles, with key turning points in the third and eighth years of storage, which is also accompanied by the colour changing from green to orange or brown, the aroma changing from a faint scent to woody and ageing, the astringency diminishing, and the sweet and mellow increasing. Theophylline was identified as the potential marker of RPT stored 1–3 years, while (−)-catechin gallate, (−)-gallocatechin gallate, quercetin, and rutin as those for a storage of 9–10 years. The volatile compounds indicate a general trend of an initial increase followed by a decrease. Forty-four key aroma compounds (OAV ≥ 1) were identified. Eucalyptol, β-Caryophyllene, 2-Amylfuran, Copaene, Estragole, and α-Terpinene originated as potential markers for RPT stored 1–3 years, while (Z)-Linalool oxide (furanoid), α-Terpineol, Terpinen-4-ol, and cis-Anethol were for RPT stored 8–10 years. This study revealed the flavour characteristics and quality changes of RPT over the course of storage, and constructed a sensory flavour wheel, providing theoretical underpinnings for the quality control and assessment of RPT. Full article

Intercropping legumes is an effective and sustainable planting pattern that has the benefit of decreasing chemical fertilizer input and improving the soil environment. However, the effects of chemical fertilizer reduction and intercropping different legumes on soil nutrients, microorganisms, and tea quality remain elusive. Hereby, compared with 100% chemical fertilizer (CK), Sesbania cannabina (SC) and Crotalaria pallida Blanco (CP) were selected as the intercropped plant with 70% chemical fertilizer to investigate its effect on soil nutrients, microorganisms, and tea quality. The results showed that compared with monocropping, intercropping legumes had greater concentrations of the soil labile organic matter, nitrate nitrogen, ammonia nitrogen, inorganic nitrogen, and alkali-hydrolyzable nitrogen. Intercropping systems significantly enhanced the content of non-ester-type catechins (catechin and gallocatechin) and ester-type catechins (epicatechin gallate). In SC, the content of gallocatechin, catechin, and epicatechin gallate increased by 146.67%, 107.69%, and 21.05%, respectively, while in CP, the content of these three compounds increased by 166.67%, 84.62%, and 19.08%, respectively. Significant differences in microbial composition were also observed under different systems. Actinobacteria, Rhodoplanes, and Thaumarchaeota were obviously enhanced in SC, while Rhodanobacter, Pseudolabrys, and Pedosphaera were manifestly improved in CP compared to those in the monoculture. Moreover, intercropping legumes significantly increased the abundances of CNP cycling functional genes, such as gpmB, mch, accD6, pgi-pmi, mcr, glmS, ACOX1 and fadB (carbohydrate metabolism), nirD and narI (nitrification), pmoB-amoB and hao (dissimilatory N reduction), and phoN (organic phosphoester hydrolysis). The relationship between intercropping systems and tea qualities was mainly established by soil nutrition and the abundance of C and N cycling functional microorganisms. This study provides more information on the relationship between soil nutrients, functional genes of microorganisms, and tea quality under tea/legume intercropping systems in tea plantations and offers a basis for the higher-performance intercropping pattern. Full article

Matcha is reported to have high content of some bioactive components such as catechins, theanine, and caffeine, and its consumption is increasing worldwide. Several analytical methods have been established for matcha powder and bioactive compounds, but most of them are based on HPLC methods. This study focused on NMR as an analytical method for simple quantitative analysis of the functional components of matcha. The analytical conditions were established by preparing extract and solvent fractions, evaluating hygroscopicity, and examining quantitative NMR parameters. The analytical performance was evaluated, and the developed analytical condition was also applied to matcha powder by directly mixing in NMR solvent without pre-extraction. Caffeine, epicatechin, epicatechin-3-O-gallate, epigallocatechin-3-O-gallate, epigallocatechin, gallocatechin-3-O-gallate, and gallocatechin were quantified. Analysis of matcha and normal green tea powder suggested the possibility of distinguishing between matcha and green tea powder by the ratio of caffeine content and total catechins content. The qNMR method can be adopted for the simple analysis of the amount of caffeine and catechin compounds in the powders and extracts. Full article

Theaflavins, as key bioactive compounds of black tea, are garnering increasing attention. However, research predominantly focuses on theaflavin monomers derived from the enzymatic oxidation of cis-type catechins. In this study, we identify a unique stereoisomer of theaflavin-3-gallate (TF-3-G), named isoneoTF-3-G, in black tea from Camellia ptilophylla (C. ptilophylla), which is rich in trans-catechins. IsoneoTF-3-G, a characteristic theaflavin of C. ptilophylla black tea, is formed by the oxidation of gallocatechin gallate and catechin. It exhibits a bright orange–red color and shows an [M+H]⁺ ion at m/z 717.1449 in positive electron spray ionization-mass spectrometry. Furthermore, isoneoTF-3-G demonstrates potent inhibitory effects on the proliferation of human colorectal carcinoma HCT116 cells, with a half-inhibitory concentration of 56.32 ± 0.34 μM. This study reveals that the mitochondrial pathway is involved in the apoptosis induction of HCT116 cells by isoneoTF-3-G. Specifically, isoneoTF-3-G leads to increased reactive oxygen species in HCT116 cells, decreased mitochondrial membrane potential, and the consequent release of cytochrome c from the mitochondria to the cytosol, activating caspase-9 and caspase-3, which further promotes the cleavage of poly(ADPribose) polymerase. The results of this study enhance our understanding of the composition and synthesis mechanisms of theaflavins and provide foundational evidence for the further development of isoneoTF-3-G and C. ptilophylla. Full article

Spray-drying is a common technique for the microencapsulation of bioactive compounds, which is crucial for improving their stability and bioavailability. In this study, the encapsulation efficiency (EE), physicochemical properties and in vitro bioaccessibility of phenolic compounds from spray-dried encapsulated phenol-rich extracts of grape pomace, a winery waste, were evaluated. Sodium alginate alone (SA) or in a mixture with gum Arabic (SA-GA) or gelatin (SA-GEL) was used as a coating. SA-GEL achieved the highest EE (95.90–98.01%) and outperformed the intestinal release of phenolics by achieving a bioaccessibility index (BI) for total phenolic compounds of 37.8–96.2%. The release mechanism of phenolics from the microcapsules adhered to Fickian diffusion. Encapsulation significantly improved the BI of individual phenolics, with the highest BI values for gallocatechin gallate (2028.7%), epicatechin gallate (476.4%) and o-coumaric acid (464.2%) obtained from the SA-GEL microcapsules. Structural analysis confirmed amorphous matrices in all systems, which improved solubility and stability. These results suggest that encapsulation by spray-drying effectively protects phenolics during digestion and ensures efficient release in the intestine, which improves bioaccessibility. This study contributes to the understanding of biopolymer-based encapsulation systems, but also to the valorisation of grape pomace as a high-value functional ingredient in sustainable food processing. Full article

Green tea kombucha, produced using a green tea (Camellia sinensis) grown in Brazil, was characterized and its in vitro bioactive properties were evaluated. Overall, 92 phenolic compounds were identified (70.7% flavonoids, 25% phenolic acids, 2.2% lignans, and 1.1% other polyphenols), contributing to the observed high antioxidant capacity. The major phenolics identified were gallocatechin, catechin 5-O-gallate, and epicatechin. Green tea kombucha exhibited antibacterial activity against all tested bacteria, being more effective against Salmonella spp. In addition, green tea kombucha demonstrated antimalarial activity against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum, and antiproliferative activity against cancer cell lines A549, HCT8, HepG2, and HUVEC. Additionally, it presented antioxidant properties by effectively reducing the generation of reactive oxygen species (ROS) and provided protection to erythrocytes against AAPH-induced oxidative stress. Thus, green tea kombucha is abundant in antioxidants and possesses intriguing bioactive properties that can be investigated by both the food and pharmaceutical sectors. Full article

Historically, botanical preparations have been used to improve human health. Their active ingredients are influenced by multiple factors such as intraspecies variations, environmental conditions, collection time and methods, and the part of the plant used. To ensure the efficiency and safety of these herbal drugs, qualitative and quantitative analyses are required. A Tessaria absinthioides decoction (DETa) was reported as having hypocholesterolemic, anti-inflammatory, cytotoxic, antitumor, and antioxidative properties. This work aimed to analyze DETa by correlating its chemical composition with cytotoxic and antioxidative properties, with the aim of promoting research on it as an anticancer agent. DETa collections (2017, 2018, 2019, and 2022) were analyzed by UHPLC-DAD, UHPLC-DAD-FLD, and UPLC-MS/MS; cytotoxicity was assessed on the MCF-7 breast cancer cell line; antioxidative capacity was evaluated by the DPPH and FRAP methods; and correlation analysis was used to determine biological and chemical markers. The results provide evidence that biological activities were consistent across the collections. Among the quantified compounds, apigenin, naringin, gallocatechin gallate, ginnalin A, myricetin, epicatechin, OH-tyrosol, quercetin, and chlorogenic, tessaric, p-coumaric, vanillic, caffeic, caftaric, ellagic, and rosmarinic acids correlated as bioactive and chemical markers. Moreover, tessaric acid could be established as a species marker. Altogether, these findings add relevant information to DETa properties, encouraging further exploration of its potential application as an anticancer botanical. Full article

Tea plant calli (Camellia sinensis L.) are characterized by the accumulation of various phenolic compounds (PC)—substances with high antioxidant activity. However, there is still no clarity on the response of tea cells to light exposure of varying intensity. The purpose of the research was to study tea callus cultures grown under the influence of primary exposure to different light intensities (50, 75, and 100 µmol·m⁻²·s⁻¹). The cultures’ growth, morphology, content of malondialdehyde and photosynthetic pigments (chlorophyll a and b), accumulation of various PC, including phenylpropanoids and flavanols, and the composition of catechins were analyzed. Primary exposure to different light intensities led to the formation of chloroplasts in tea calli, which was more pronounced at 100 µmol·m⁻²·s⁻¹. Significant similarity in the growth dynamics of cultures, accumulation of pigments, and content of malondialdehyde and various phenolics in tea calli grown at light intensities of 50 and 75 µmol·m⁻²·s⁻¹ has been established, which is not typical for calli grown at 100 µmol·m⁻²·s⁻¹. According to data collected using high-performance liquid chromatography, (+)-catechin, (−)-epicatechin, epigallocatechin, gallocatechin gallate, epicatechin gallate, and epigallocatechin gallate were the main components of the tea callus culture’s phenolic complex. Its content changed under the influence of primary exposure to light, reaching the greatest accumulation in the final stages of growth, and depended on the light intensity. The data obtained indicate changes in the morphophysiological and biochemical characteristics of tea callus cultures, including the accumulation of PC and their individual representatives under primary exposure to light exposure of varying intensity, which is most pronounced at its highest values (100 µmol·m⁻²·s⁻¹). Full article

Phenolic compounds are the predominant chemical constituents in the secondary metabolites of plants and are commonly found in pears. In this study, we focused on the analysis of the phenolic composition and antioxidant activity of leaves from five pear cultivars (Cuiguan, Chaohong, Kuerle, Nanguoli, and Yali) and tea leaves (Fudingdabai as the control) using ultra-performance liquid chromatography coupled with electrospray ionization triple quadrupole mass spectrometry. The results indicated significant differences in the amount and composition of phenolic metabolites between tea and pear leaves, as well as among the five pear varieties. Only approximately one-third of the metabolites exhibited higher levels in pear leaves compared to that in tea leaves. The total phenol content in the Yali cultivar was higher than that in the other pear cultivars. Furthermore, specific phenolic metabolites with high expression were identified in the leaves of different groups. The levels of delphinidin 3-glucoside, aesculin, prunin, cosmosiin, quercetin 3-galactoside, isorhamnetin-3-O-glucoside, nicotiflorin, narcissin, chlorogenic acid, and cryptochlorogenic acid were relatively high among the five pear cultivars. (-)-Gallocatechin gallate, 6-methylcoumarin, aesculetin, hesperidin, kaempferol, and caftaric acid were identified as specific metabolic substances unique to each type of pear leaf. Most of the differential metabolites showed positive correlations and were primarily enriched in the flavonoid biosynthesis, flavone and flavonol biosynthesis, and phenylpropanoid biosynthesis pathways. DPPH (1,1-Diphenyl-2-picrylhydrazyl radical) analysis indicated that the Yali cultivar exhibited the highest antioxidant activity compared to other varieties. This systematic analysis of the differences in phenolic metabolite composition and antioxidant activity between pear and tea leaves provides a theoretical foundation for the development and utilization of pear leaf resources. Full article

This study investigated the effects of various characteristic components of tea—theaflavins, catechins, thearubigins, theasinensins, theanine, catechin (C), catechin gallate (CG), epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), epigallocatechin gallate (EGCG), gallocatechin (GC), and gallocatechin gallate (GCG)—on acrylamide formation. The results revealed that most of tea’s characteristic components could significantly eliminate acrylamide, ranked from highest to lowest as follows: GC (55.73%) > EC (46.31%) > theaflavins (44.91%) > CG (40.73%) > thearubigins (37.36%) > ECG (37.03%) > EGCG (27.37%) > theabrownine (22.54%) > GCG (16.21%) > catechins (10.14%) > C (7.48%). Synergistic elimination effects were observed with thearubigins + EC + GC + CG, thearubigins + EC + CG, thearubigins + EC + GC, theaflavins + GC + CG, and thearubigins + theaflavins, with the reduction rates being 73.99%, 72.67%, 67.62%, 71.03%, and 65.74%, respectively. Tea’s components reduced the numbers of persistent free radicals to prevent acrylamide formation in the model system. The results provide a theoretical basis for the development of low-acrylamide foods and the application of tea resources in the food industry. Full article

This study aimed to evaluate the effects of supplementation with ethanolic and aqueous extracts from the bark of the stem of Guazuma ulmifolia in mice submitted to a high-fat diet as well as to evaluate the chemical composition of these extracts. The chemical composition and antioxidant potential was evaluated in aqueous and ethanolic extracts of the stem bark. The in vivo test consisted of evaluating the effects of the aqueous and ethanolic extracts of the stem bark on C57BL/6 mice receiving a high-fat diet. The animals were evaluated for weight gain, feed consumption, visceral adiposity, serum, and inflammatory and hormonal parameters. The results of the chemical analyses corroborate those obtained by the literature, which reported gallocatechin, epigallocatechin and epigallocatechin gallate. Compared with the ethanolic extract, the aqueous extract showed greater antioxidant capacity. Both extracts resulted in lower feed consumption in the animals, but they did not influence weight gain or visceral adiposity and resulted in varied changes in the lipid profile. In addition, they did not influence glucose tolerance, insulin sensitivity, or fasting blood glucose. Furthermore, the leptin levels increased, which may have contributed to satiety, but this was shown to have a negative impact on other inflammatory and hormonal parameters. Therefore, under the conditions of this study, the biologically active compounds present in the plant species Guazuma ulmifolia were not able to contribute to the treatment of metabolic changes related to the consumption of a high-fat diet. Full article

Triadica cochinchinensis honey (TCH) is collected from the nectar of the medicinal plant T. cochinchinensis and is considered the most important honey variety in southern China. TCH has significant potential medicinal properties and commercial value. However, reliable markers for application in the authentication of TCH have not yet been established. Herein, a comprehensive characterization of the botanical origin and composition of TCH was conducted by determining the palynological characteristics and basic physicochemical parameters. Liquid chromatography tandem-mass spectrometry (LC-MS/MS) was used to investigate the flavonoid profile composition of TCH, T. cochinchinensis nectar (TCN) and 11 other common varieties of Chinese commercial honey. (−)-Gallocatechin gallate (GCG) was identified as a reliable flavonoid marker for TCH, which was uniquely shared with TCN but absent in the other 11 honey types. Furthermore, the authentication method was validated, and an accurate quantification of GCG in TCH and TCN was conducted. Overall, GCG can be applied as a characteristic marker to identify the botanical origin of TCH. Full article

Metabolic syndrome (MetS) significantly predisposes individuals to diabetes and is a prognostic factor for the progression of diabetic nephropathy (DN). This study aimed to evaluate the efficacy of (-)–gallocatechin gallate (GCG) in alleviating signs of MetS-associated DN in db/db mice. We administered GCG and monitored its effects on several metabolic parameters, including food and water intake, urinary output, blood glucose levels, glucose and insulin homeostasis, lipid profiles, blood pressure, and renal function biomarkers. The main findings indicated that GCG intervention led to marked improvements in these metabolic indicators and renal function, signifying its potential in managing MetS and DN. Furthermore, transcriptome analysis revealed substantial modifications in gene expression, notably the downregulation of pro-inflammatory genes such as S100a8, S100a9, Cd44, Socs3, Mmp3, Mmp9, Nlrp3, IL–1β, Osm, Ptgs2, and Lcn2 and the upregulation of the anti-oxidative gene Gstm3. These genetic alterations suggest significant effects on pathways related to inflammation and oxidative stress. In conclusion, GCG demonstrates therapeutic efficacy for MetS–associated DN, mitigating metabolic disturbances and enhancing renal health by modulating inflammatory and oxidative responses. Full article