Search Results (1,938)

Antimicrobial resistance represents a major global health challenge, highlighting the urgent need for alternative bioactive compounds from natural sources. This study investigated the phytochemical composition and antimicrobial potential of saponin-enriched extracts from the trunk bark of Argania spinosa (L.) Skeels, collected from two contrasting Algerian regions: the coastal area of Stidia (ES) and the Saharan region of Tindouf (ET). Extraction yields were comparable (approximately 12.6%). UHPLC-MS analysis revealed distinct phytochemical profiles, with ES enriched in oleanane-type saponins and flavonoids, whereas ET showed a higher abundance of bayogenin-type derivatives. Key compounds included arganine C, E, and J, as well as catechin and quercetin. Antimicrobial activity was evaluated using agar well diffusion and broth microdilution assays against clinically relevant microorganisms, including the reference strains Staphylococcus aureus and Listeria innocua, together with Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Proteus mirabilis, and Candida albicans. Both extracts exhibited broad-spectrum antimicrobial activity, although ES consistently showed lower Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal, Fungicidal Concentration (MBC)/(MFC) values than ET. MIC values ranged from 25 to 50 mg/mL for ES and from 50 to 100 mg/mL for ET. Synergistic interactions were observed between ES and gentamicin against S. aureus and between both extracts and kanamycin against K. pneumoniae. Membrane permeability assays demonstrated that both extracts increased bacterial membrane permeability, with ET producing a stronger permeabilizing effect. Atomic force microscopy of ES-treated cells revealed marked alterations in bacterial surface morphology, while molecular docking supported strong interactions of mi-saponin B and arganine derivatives with key bacterial targets. Collectively, these findings highlight the potential of A. spinosa bark saponins as natural antimicrobial agents and promising antibiotic adjuvants against multidrug-resistant pathogens. Full article

Phytochemical studies performed on the aerial parts of Teucrium davaeanum Coss. resulted in the isolation of an iridoid diglycoside, teucardoside; two phenylethanoid triglycosides, poliumoside and 3-O-methyl-poliumoside; a flavon C-diglycoside, vicenin-2 (apigenin-6,8-di-C-glycoside); and a newly described bisdesmosidic oleanane-type triterpene saponin, davaeanoside. Structure elucidations of all isolated metabolites are based on extensive spectroscopic analysis and chemical derivatizations. The extract and isolated compounds (1–5) were tested for α-amylase and α-glucosidase inhibitory activity. IC50 values were measured for all extracts and compounds and compared against acarbose. Results revealed weak or moderate α-amylase and α-glucosidase inhibitory activity at the tested concentrations of the isolated compounds, especially compound 5. However, these findings do not exclude antidiabetic activity mediated by other mechanisms such as modulation of insulin signaling, enhancement of glucose uptake, or antioxidant effects. Further studies are warranted to explore these potential pathways. In addition, the essential oils of T. davaeanum and T. zanonii were obtained by hydrodistillation and simultaneously analyzed by GC-FID and GC/MS. The major compounds of T. davaeanum essential oil were germacrene D (31.4%) and bicyclogermacrene (15.9%); the main compounds of T. zanonii were β-pinene (19.5%), α-muurolene (13.4%), oxo-7,8-dihydro-β-ionol (9.2%), and α-pinene (6.9%). Full article

Radix pseudostellariae saponins (RPS) enhance immune responses in animals; however, the regulatory mechanisms of these effects remain unclear. This study observed that 14 days post-intranasal immunization with RPS and a Mycoplasma gallisepticum-attenuated vaccine (MGAV), MGAV-specific antibody titers were significantly increased in the blood, and chemokine (C-C motif) ligand 5 (CCL5) messenger RNA expression was significantly increased in the trachea and blood of chickens. Transcriptomic analysis demonstrated that RPS treatment significantly upregulated specific Kyoto Encyclopedia of Genes and Genomes pathways, notably the cytokine–cytokine receptor interaction pathway, which is linked to immune cell migration and involves chemokine receptor chemokine (C-C motif) receptor 4 (CCR4). This finding was corroborated at the protein level by immunohistochemical evidence showing increased CCL5 expression in tracheal tissue. In vitro studies showed that RPS enhanced the phagocytic capacity of RAW264.7 macrophages against ovalbumin, with immunofluorescence revealing time-dependent and dose-dependent CCL5 in these cells. Transwell and scratch-healing assays confirmed that RPS promoted this migration of both RAW264.7 cells and CCR4-positive lymphocytes. Collectively, the findings revealed that RPS modulated the activation, chemotaxis, and migration of macrophages and lymphocytes and is associated with the promotion of the CCL5/CCR4 signaling axis, providing novel evidence for the immune-enhancing effects of RPS by enhancing immunogenicity. Full article

Diabetes mellitus (DM) is a complex metabolic disorder characterized by chronic hyperglycemia and represents a major global public health concern due to its rapidly increasing prevalence. Although current pharmacological therapies effectively achieve glycemic control, their long-term use is limited by adverse effects, high costs, patient compliance issues, and increasing interest in safer, multi-targeted therapeutic strategies. In this context, plant-derived bioactive compounds have gained attention as complementary or alternative approaches to metabolic disease management. Gymnema sylvestre (Retz.) R.Br. ex Sm (GS), traditionally known as “gurmar” (“sugar destroyer”), is one of the most extensively studied medicinal plants with significant antidiabetic potential. This review evaluates the antidiabetic effects of G. sylvestre, focusing on its phytochemical composition, molecular mechanisms, and impact on diabetes-related complications. Major bioactive constituents, including triterpenoid saponins (gymnemic acids), gurmarin-like peptides, flavonoids, and sterols, regulate glucose homeostasis, inhibit intestinal glucose absorption, preserve pancreatic β-cell function, stimulate insulin secretion, modulate lipid metabolism, and suppress inflammatory signaling pathways. Experimental and clinical evidence indicates that G. sylvestre modulates oxidative stress and inflammation associated with complications such as nephropathy, neuropathy, retinopathy, vascular dysfunction, and dyslipidemia. This review adopts a mechanism-oriented framework integrating phytochemical structure–molecular target–metabolic outcome relationships and discusses emerging strategies, including nanotechnology-based delivery systems, molecular docking, and multi-component phytotherapy. Overall, G. sylvestre represents a promising multi-target phytotherapeutic agent, highlighting directions for future mechanistic and clinical research. Full article

Medicine food homology (MFH) plants are rich in nutrients and bioactive specialized metabolites, and their endophytic fungi mediate key biotransformation of host secondary metabolites. Licorice, a representative MFH herb, accumulates glycyrrhizin (GL) as its dominant bioactive triterpenoid saponin. Its hydrolysates glycyrrhetinic acid (GA) and glycyrrhetinic acid 3-O-mono-β-D-glucuronide (GAMG) show stronger bioactivity and bioavailability than GL. However, the enzymatic mechanisms of licorice-derived endophytic fungi-mediated GL biotransformation remain unclear. Here, nine licorice endophytic fungi were screened for significant GL-inducible β-glucuronidase activity. Four functional GH2 β-glucuronidase were obtained by prokaryotic and eukaryotic expression systems, and confirmed to catalyze glycyrrhizin biotransformation via two distinct hydrolytic pathways. Inoculation of these four strains into licorice markedly enhanced host glycyrrhizin accumulation. This study provides novel enzymatic resources for the efficient bioproduction of high-value glycyrrhizin derivatives, and proposes a green strategy to improve glycyrrhizin content in licorice, deepening the understanding of endophyte–host metabolic crosstalk in medicinal herbs. Full article

Microbial α-L-rhamnosidases are increasingly recognised as selective biocatalysts in food biotechnology, nutraceutical production, and health-related applications. These glycoside hydrolases catalyse the hydrolysis of terminal alpha-L-rhamnose residues from flavonoids, terpenoids, saponins, and other glycosylated natural products, thereby modulating sensory properties, solubility, intestinal absorption, and biological activity. While their traditional uses include debittering citrus juice and enhancing wine aroma, recent evidence demonstrates their wider value in selective flavonoid biotransformation, production of rare mono-glycosylated derivatives, probiotic fermentations, and microbiome-associated metabolism. This review summarises microbial sources, catalytic mechanisms, CAZy classification, substrate specificity, structure–function relationships, analytical methods, industrial process engineering, and emerging applications in functional foods and targeted nutraceutical applications. Particular attention is given to the distinction between alpha-(1→2)- and alpha-(1→6)-linked substrates, the production of isoquercitrin and prunin, recombinant enzyme platforms, immobilised biocatalysts, and potential future opportunities arising from metagenomics, synthetic biology, and AI-assisted protein engineering. Full article

Background/Objectives: Strangles, caused by Streptococcus equi subspecies equi (S. equi), remains a common and severe equine infectious disease. Strangvac^®, a recombinant fusion protein vaccine licenced in Europe, contains the antigens (Ag) CCE, Eq85, IdeE and a saponin adjuvant. Although its efficacy is high (94% in clinical trials and 100% in some natural outbreaks), immune correlates of protection have not been defined. This study determined the antibody (Ab) thresholds predictive of protection against clinical disease following high-dose experimental S. equi infection and the expected levels of protection at 6 and 12 months after V2. Methods: This study was a retrospective analysis of six independent double-blinded placebo-controlled experimental infection studies involving 129 ponies (80 vaccinated controls and 49 placebo controls) and a serology study (12 vaccinated ponies). Ponies received two to five vaccine doses before being experimentally challenged with S. equi strain Se4047. Ponies in the serology study were not experimentally infected. The onset of pyrexia (≥39 °C for at least 2 of 3 consecutive days, OOT) was used as a disease marker. Serology to IdeE, Eq85 and CCE was analysed with standardised clinical outcomes to define protective thresholds through correlation and Receiver Operating Characteristic (ROC) analyses. The predicted level of protection up to one year after V2 was then calculated (duration of immunity: DOI). Results: A protection threshold of ≥10 days to OOT, derived from the control distribution, was used for ROC modelling. Predictive performance (e.g., accuracy, precision, specificity) was calculated for individual and combined Ab thresholds. All controls developed pyrexia (median 6 days, IQR 5–7), with 46 out of 49 (93.9%) within 9 days of the challenge. Vaccinated ponies showed significantly delayed or absent OOT compared with controls (p < 0.0001), with 37 vaccinated ponies (46.25%) reaching the end of the studies without developing pyrexia. The Ab titre to all antigens was significantly associated with the level of protection (p < 0.0001). ROC analyses demonstrated high discriminative power (AUC 0.86–0.88). Optimal Ab titre boundaries yielded high precision (≥80%) for all Ags (IdeE: 3.5–4.3; Eq85: 2.65–3.7 and CCE: 2.66–3.2). Both precision and accuracy remained above 80% for levels of IdeE and Eq85 Ab titres superior or equal to those measured up to one year after V2, with an estimated level of protection of 78.9% to 81.2% in vaccinated animals. Conclusions: Ab titres to all three Ags represent robust correlates of protection against pyrexia following high-dose experimental S. equi challenge in Strangvac^®-vaccinated ponies. Ab titres measured up to one year after V2 were estimated to continue to provide significant protection in vaccinated animals. These findings support the observed levels of protection conferred by Strangvac^® against natural infection with S. equi. Full article

Copper is an essential trace element for plant growth; however, in excessive amounts, it can cause severe toxicity by inducing bursts of reactive oxygen species and disrupting metabolic balance. As a root-based medicinal plant and food, Platycodon grandiflorus has its roots in direct contact with the soil. Its ability to accumulate copper is the most pronounced among various heavy metals; consequently, it is particularly susceptible to copper stress, which in turn affects its normal growth and medicinal quality. This paper focuses on the intrinsic stress potential and possible response pathways of Platycodon grandiflorus to copper stress. Drawing on existing research and relevant literature, it conducts an integrated analysis of its defence mechanisms across four levels: physical barriers, non-enzymatic antioxidants, conserved physiological and biochemical pathways, and transcriptional regulation. Regarding physical barriers, the cell wall forms the first line of defence through pectin adsorption and lignin deposition; in terms of endogenous antioxidant defence, secondary metabolites such as polysaccharides and saponins can directly participate in the scavenging of reactive oxygen species; regarding conserved pathways, the glutathione–phytochelate system acts in concert with antioxidant enzymes such as SOD and CAT to participate in copper ion chelation and the alleviation of oxidative stress, with hormone signalling regulation also playing a crucial coordinating role in this process; regarding transcriptional regulation, transcription factors such as PgWRKY may mediate the perception of stress signals and the expression of downstream genes. These pathways act in a coordinated and sequential manner, collectively forming a multi-level defence network through which Platycodon grandiflorus responds to copper stress. At the same time, this paper highlights the functional limitations of this defence system, summarises the shortcomings in current research, and proposes directions for future studies, with a view to guiding the safe cultivation and quality assurance of Platycodon grandiflorus in copper-polluted areas, as well as for the breeding of heavy-metal-tolerant medicinal plants. Full article

Porcine coronavirus is one of the prevalent enteric coronaviruses in pigs, causing watery diarrhea and even death in suckling piglets and resulting in giant losses to the pig industry. However, effective antiviral strategies against PDCoV remain limited. Notoginsenoside R1 (NG-R1), a saponin extracted from Panax notoginseng, exhibits diverse bioactivities, but its antiviral potential has not been fully characterized. Herein, we systematically investigated the anti-PDCoV effect of NG-R1 and its underlying mechanism. NG-R1 showed no cytotoxic effect on LLC-PK1 cells and exerted antiviral ability against PDCoV infection through targeting the whole life cycle of the virus. In addition, network pharmacology analysis identified calcium signaling as a potentially relevant pathway involved in the antiviral activity of NG-R1. Further data demonstrated that PDCoV infection disrupted intracellular calcium homeostasis, whereas NG-R1 treatment partially restored calcium balance and attenuated endoplasmic reticulum (ER) stress. Moreover, NG-R1 modulated the expression of SERCA2, a key regulator of ER calcium transport. Thapsigargin, an inhibitor of SERCA2, showed similar antiviral capacity to NG-R1. Collectively, our findings suggest that NG-R1 exerts antiviral activity against PDCoV, potentially through regulation of calcium homeostasis mediated by SERCA2. This study provides a theoretical basis for the development of novel antiviral agents targeting calcium signaling pathways. Full article

In contemporary research on natural bioactive compounds, increasing emphasis is placed on the development of efficient and sustainable extraction technologies. This study aimed to develop and optimize an innovative extraction process for wild cyclamen (Cyclamen purpurascens Mill.) tubers to maximize the yield of total extractives using a Box–Behnken design. The effects of four extraction parameters were evaluated on the system response. A second-order polynomial model accurately described the extraction process, yielding a coefficient of determination of 0.919. The liquid-to-solid ratio was identified as the dominant factor affecting the extraction efficiency compared to the other factors investigated. The optimal extraction conditions were as follows: extraction time of 15.5 min, 13% (v/v) ethanol, liquid-to-solid ratio of 13.5 mL/g, and extraction temperature of 34 °C, resulting in a yield of 53.44%. The optimized process yielded a significant saponin content of 16.19 g/100 g, while the levels of phenolic compounds (132.52 mg GAE/100 g) and flavonoids (12.04 mg QE/100 g) were also quantified. UHPLC–ESI–MS/MS analysis confirmed the presence of triterpene saponins, flavonoids, and terpenoids. DPPH, ABTS⁺, and CUPRAC assays indicated the antioxidant potential of the extract, while the minimum inhibitory concentration assay showed antibacterial activity against Staphylococcus aureus and Escherichia coli. The established chemical profile and observed biological activities provide the basis for further evaluation of wild cyclamen tubers as a source of bioactive secondary metabolites. Full article

Plant-derived bioactive compounds, such as polyphenols and saponins, possess significant pharmacological value. However, conventional extraction methods often suffer from low efficiency, poor bioavailability, and environmental burdens. Aspergillus-based biotransformation has emerged as a superior platform for overcoming these limitations due to their robust secretomes, versatile metabolic networks, and the GRAS (Generally Recognized as Safe) status of specific industrially relevant species (e.g., A. oryzae and A. niger). Existing literature frequently focuses on isolated compounds or general fungal processes. To fill this gap, this review systematically links specific Aspergillus enzymatic systems to an “enzymatic hydrolysis–transformation–synthesis” closed-loop framework, which is essential for industrial-scale valorization. In this review, we summarize recent advances in the biotransformation of phytochemicals by A. niger, A. oryzae, and A. nidulans. These fungi utilize specialized enzymes—including β-glucosidases, cellulases, and glycosidases—to enable precise hydrolysis, deglycosylation, and detoxification under mild conditions. We highlight representative transformations that demonstrate markedly enhanced bioactivity and solubility. Key examples include the conversion of polydatin to resveratrol (>90% yield) and ginsenoside Rb1 to ginsenoside compound K (94.4% conversion rate). Although industrial applications span the food, pharmaceutical, and cosmetic sectors, significant challenges persist in solid-state fermentation (SSF) scale-up, strain stability, target compound over-degradation, and downstream purification. Genetic engineering, process optimization and hybrid bioprocessing are highlighted as promising strategies to overcome these limitations and realize sustainable, high-value production of natural bioactive metabolites. Full article

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by recurrent intestinal inflammation and mucosal injury. This study evaluated the protective potential of red ginseng ethanolic extract (RGEE) using a dextran sulfate sodium (DSS)-induced colitis mouse model and an LPS-stimulated RAW 264.7 macrophage model. Preliminary LC-MS profiling was also performed to characterize the detectable chemical features of RGEE. In vivo, RGEE alleviated DSS-induced body weight loss, disease activity, colon shortening, spleen enlargement, and histopathological injury, with the histopathological score reduced by approximately 51.1%. RGEE also partially improved DSS-induced hematological alterations without causing obvious changes in major organ weights. In vitro, RGEE showed no obvious cytotoxicity up to 250 μg/mL and reduced LPS-induced NO, TNF-α, IL-6, and IL-1β production by approximately 60.0–67.1%. LC-MS analysis putatively annotated several saponin-related features, including notoginsenoside R1 and ginsenosides Rb1, Rb2, Rh1, Rh4, and Rh2. These findings suggest that RGEE has protective potential against DSS-induced colitis, which is associated with the suppression of inflammatory mediator production. Further studies are needed to clarify its active constituents and mechanisms of action. Full article

Aging is associated with a rising burden of chronic metabolic, cardiovascular, musculoskeletal, and neurodegenerative diseases that share interconnected pathological mechanisms, including oxidative stress, chronic inflammation, mitochondrial dysfunction, metabolic imbalance, and immune dysregulation. Because these disorders arise from complex and overlapping biological disturbances, conventional single-target therapies often provide only limited benefit. In this context, traditional Chinese herbal medicines, characterized by multi-component and multi-target actions, are being re-evaluated using modern pharmacological and systems biology approaches. Among these, Astragalus membranaceus and Cordyceps species have attracted attention as representative tonic medicines with long-standing traditional use and growing biomedical relevance. Their principal bioactive constituents, including polysaccharides, saponins, flavonoids, sterols, and nucleoside derivatives such as cordycepin, exert pleiotropic effects on inflammatory signaling, redox homeostasis, mitochondrial function, metabolic regulation, and immune responses. This review summarizes current evidence on bioactive derivatives from Astragalus and Cordyceps in aging-related chronic and neurodegenerative disorders, including diabetes, cardiovascular dysfunction, osteoarthritis, cancer, Alzheimer’s disease, and Parkinson’s disease. It focuses on mechanistic findings from cellular and animal studies and critically discusses key translational challenges, such as compositional variability, poor bioavailability, lack of standardized preparation, limited clinical validation, and safety concerns related to toxicity and herb–drug interactions. Full article

Objective: This study aimed to evaluate the effects of 12 weeks of Astragalus membranaceus saponins (AMS) supplementation on functional performance, knee joint mobility, self-reported outcomes, and biomarkers of inflammation and cartilage in healthy subjects with knee discomfort. Methods: A randomized, double-blind, placebo-controlled trial was conducted in healthy subjects aged 20–70 years with knee discomfort but without clinically diagnosed knee osteoarthritis. Participants were assigned to receive one capsule of AMS or a placebo once daily for 12 weeks. The pre-specified primary endpoints were the SLSD step count and knee ROM; KOOS total score was a key secondary endpoint; serum biomarkers were exploratory. The results included functional performance assessed by the Single Leg Step Down (SLSD) test, knee range of motion (ROM), and self-reported outcomes using the Knee injury and Osteoarthritis Outcome Score (KOOS). Knee ROM was measured with a goniometer and recorded as both active ROM and passive ROM for knee flexion and extension. Serum biomarkers of inflammation (IL-8, IL-1β, MIP-1α), cartilage degradation (CTX-II, COMP, MMP-13, COL2A1), and cartilage synthesis (PIINP) were evaluated at baseline and Week 12. Results: Within the AMS group, SLSD step count increased significantly by 16.83% (Δ = +12.78 steps; p < 0.05) and recovery time decreased significantly by 19.12% (Δ = −108.91 s; p < 0.05) compared with baseline, whereas the placebo group showed smaller, non-significant changes (+4.48 steps and −56.48 s, respectively); however, neither between-group difference in change scores reached statistical significance. Significant improvements in active and passive knee ROM were observed in both flexion and extension (all p < 0.05) within the AMS group, whereas the placebo group showed no significant changes. KOOSs improved significantly in all domains within the AMS group, with the largest gains observed in sport/recreation (+22.23%) and quality of life (+18.38%). In the exploratory biomarker analysis, several inflammation and cartilage-related biomarkers changed after AMS supplementation showed within-group reductions (IL-8, COMP, MMP-13) and PIINP increased. Conclusions: 12 weeks of AMS supplementation was associated with improvements in selected functional, mobility, and outcomes in generally healthy adults with self-reported knee discomfort. AMS was also associated with changes in selected circulating biomarkers related to inflammation and cartilage metabolism. These findings should be interpreted as a preliminary, safe, complementary strategy to support joint health in healthy subjects with knee discomfort. Full article