Evaluation of the potential of endophytic Trichoderma sp. isolated from medicinal plant Ampelopsis japonica against MRSA and bioassay-guided separation of the anti-MRSA compound.

Endophytic fungi have been recognized as a valuable source for the production of biologically active compounds with potential applications in various domains. This study aimed to isolate endophytic fungi from Ampelopsis japonica (Thunb.) Makino and assess their anti-MRSA activity. Meanwhile, chromatographic separation techniques were applied to analyze the constituents of endophytic fungal secondary metabolites. The isolate BLR24, which exhibited strong inhibition activity against MRSA, was identified as Trichoderma virens based on morphological characteristics and ITS sequence analyses. The ethyl acetate extract of BLR24 (EA-BLR24) showed good anti-MRSA activity with the MIC and MBC values of 25 µg/mL and 50 µg/mL, separately. The inhibition of biofilm formation was up to 34.67% under MIC concentration treatment. Meanwhile, EA-BLR24 could significantly reduce the expression of biofilm-related genes (icaA, sarA, and agrA) of MRSA. Based on LC-MS/MS analysis, twenty compounds in EA-BLR24 could be annotated using the GNPS platform, mainly diketopiperazines. The anti-MRSA compound (Fr.1.1) was obtained from EA-BLR24 by bioassay-guided fractionation and determined as gliotoxin. The results indicated that endophytic Trichoderma virens BLR24 isolated from the medical plant A. japonica roots could be a promising source of natural anti-MRSA agents. Endophytic fungal secondary metabolites are abundant in biologically active compounds. Endophytic fungi from medicinal plants could be a source yielding bioactive metabolites of pharmaceutical importance.

The effect of vine tea (Ampelopsis grossedentata) extract on fatigue alleviation via improving muscle mass.

ETHNOPHARMACOLOGICAL RELEVANCE: Vine Tea (VT, Ampelopsis grossedentata), boasts a venerable tradition in China, with a recorded consumption history exceeding 1200 years. Predominantly utilized by ethnic groups in southwest China, this herbal tea is celebrated for its multifaceted therapeutic attributes. Traditionally, VT has been employed to alleviate heat and remove toxins, exhibit anti-inflammatory properties, soothe sore throats, lower blood pressure, and fortify bones and muscles. In the realm of functional foods derived from plant resources, VT has garnered attention for its potential in crafting anti-fatigue beverages or foods, attributed to its promising efficacy and minimal side effects. Currently, in accordance with the Food Safety Standards set forth by the Monitoring and Evaluation Department of the National Health and Family Planning Commission in China, VT serves as a raw material in various beverages. AIM OF THE STUDY: VT has an anti-fatigue or similar effect in folk. However, the underlying molecular mechanisms contributing to VT's anti-fatigue effects remain elusive. This study endeavors to investigate the influence of Vine Tea Aqueous Extract (VTE) on fatigue mitigation and to elucidate its operative mechanisms, with the objective of developing VTE as a functional beverage. MATERIALS AND METHODS: The preparation of VTE involved heat extraction and freeze-drying processes, followed by the identification of its metabolites using UPLC-QTOF-MS to ascertain the chemical composition of VTE. A fatigue model was established using a forced swimming test in mice. Potential molecular targets were identified through network pharmacology, transcriptome analysis, and molecular docking. Furthermore, RT-PCR and Western blot techniques were employed to assess mRNA and protein expressions related to the AMPK and FoxO pathways. RESULTS: VTE significantly prolonged the duration of swimming time in an exhaustive swimming test in a dose-dependent manner, while simultaneously reducing the concentrations of blood lactic acid (LA), lactate dehydrogenase (LDH), serum urea nitrogen (SUN), and creatine kinase (CK). Notably, the performance of the high-dose VTE group surpassed that of the well-recognized ginsenoside. VTE demonstrated a regulatory effect akin to ginsenoside on the AMPK energy metabolism pathway and induced downregulation in the expression of Gadd45α, Cdkn1a, FOXO1, and Fbxo32 genes, suggesting an enhancement in skeletal muscle mass. These findings indicate that VTE can improve energy metabolism and muscle mass concurrently. CONCLUSIONS: VTE exhibits significant anti-fatigue effects, and its mechanism is intricately linked to the modulation of the AMPK and FoxO pathways. Crucially, no caffeine or other addictive substances with known side effects were detected in VTE. Consequently, vine tea shows substantial promise as a natural resource for the development of anti-fatigue beverages within the food industry.

Integrating multi-level interactive network and in vivo/vitro studies to explore the protective mechanism of Ampelopsis grossedentata in hyperuricemia.

The strategies or drugs for preventing and treating Hyperuricemia (HUA) are still lacking. As a traditional Chinese medicine (TCM) with a profound history, Ampelopsis grossedentata has been shown to play diverse biological roles. The purpose of the present study was to evaluate hypouricemic effect of A. grossedentata, and investigate its involved material basis and mechanism. A HUA mice model was established to evaluate the therapeutic effects of A. grossedentata. And then some extracts from A. grossedentata were prepared, isolated and analyzed. Furthermore, network pharmacology, based on the above results, was used to discover potential active ingredients and therapeutic targets, and they were further verified and explored by molecular docking and in vitro experiments. In vivo experiments showed that A. grossedentata exerted hypouricemic effect on mice of HUA. The core active ingredients (quercetin, myricetin and dihydromyricetin etc.) and core targets (PTGS2, XOD and ABCG2 etc.) for A. grossedentata to treat HUA were predicted by network pharmacology. And molecular docking showed that the spontaneous binding activities of above components and targets were marvelous. In vitro experiments further demonstrated that A. grossedentata exerted hypouricemic effect by decreasing the levels of UA, XOD, antioxidant factors, inflammatory factors, GLUT9 and URAT1 in HK-2 cells of HUA. Taken together, this study integrates multi-level interaction network with in vivo/vitro experiments to systematically reveal the material basis and mechanism of A. grossedentata in treating HUA, which provides a scientific basis for further study of A. grossedentata and HUA.

Chemical Constituents and α-Glucosidase Inhibitory, Antioxidant and Hepatoprotective Activities of Ampelopsis grossedentata.

Ampelopsis grossedentata is a valuable medicinal and edible plant, which is often used as a traditional tea by the Tujia people in China. A. grossedentata has numerous biological activities and is now widely used in the pharmaceutical and food industries. In this study, two new flavonoids (1-2) and seventeen known compounds (3-19) were isolated and identified from the dried stems and leaves of A. grossedentata. These isolated compounds were characterized by various spectroscopic data including mass spectrometry and nuclear magnetic resonance spectroscopy. All isolates were assessed for their α-glucosidase inhibitory, antioxidant, and hepatoprotective activities, and their structure-activity relationships were further discussed. The results indicated that compound 1 exhibited effective inhibitory activity against α-glucosidase, with an IC50 value of 0.21 µM. In addition, compounds 1-2 demonstrated not only potent antioxidant activities but also superior hepatoprotective properties. The findings of this study could serve as a reference for the development of A. grossedentata-derived products or drugs aimed at realizing their antidiabetic, antioxidant, and hepatoprotective functions.

China Medicinal Plants of the Ampelopsis grossedentata-A Review of Their Botanical Characteristics, Use, Phytochemistry, Active Pharmacological Components, and Toxicology.

Ampelopsis grossedentata (AG) is mainly distributed in Chinese provinces and areas south of the Yangtze River Basin. It is mostly concentrated or scattered in mountainous bushes or woods with high humidity. Approximately 57 chemical components of AG have been identified, including flavonoids, phenols, steroids and terpenoids, volatile components, and other chemical components. In vitro studies have shown that the flavone of AG has therapeutic properties such as anti-bacteria, anti-inflammation, anti-oxidation, enhancing immunity, regulating glucose and lipid metabolism, being hepatoprotective, and being anti-tumor with no toxicity. Through searching and combing the related literature, this paper comprehensively and systematically summarizes the research progress of AG, including morphology, traditional and modern uses, chemical composition and structure, and pharmacological and toxicological effects, with a view to providing references for AG-related research.

Investigating the antibacterial mechanism of Ampelopsis cantoniensis extracts against methicillin-resistant Staphylococcus aureus via in vitro and in silico analysis.

Methicillin-resistant Staphylococcus aureus (MRSA) is a critical pathogen responsible for a wide variety of serious infectious diseases in humans. The accelerated phenomena of drug tolerance, drug resistance, and dysbacteriosis provoked by antibiotic misuse are impeding the effectiveness of contemporary antibiotic therapies primarily used to treat this common worldwide pathogen. In this study, the antibacterial activity of 70% ethanol extract and multiple polar solvents of Ampelopsis cantoniensis were measured against the clinical MRSA isolate. The agar diffusion technique was employed to determine the zone of inhibition (ZOI), accompanied by the use of a microdilution series to identify the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Our results revealed that the ethyl acetate fraction exhibited the most significant antibacterial activity, which was determined to be bacteriostatic based on the MBC/MIC ratio 8. A list of compounds isolated from A. cantoniensis was computationally studied to further investigate the mechanism of action with the bacterial membrane protein PBP2a. The combination of molecular docking and molecular dynamics methods showed that the main compound, dihydromyricetin (DHM), is expected to bind to PBP2a at allosteric site. In addition, DHM was identified as the major compound of ethyl acetate fraction, which accounts for 77.03 ± 2.44% by high performance liquid chromatography (HPLC) analysis. As a concluding remark, our study addressed the antibacterial mechanism and suggested the prioritization of natural products derived from A. cantoniensis as a potential therapy for MRSA.Communicated by Ramaswamy H. Sarma.

Identification of an effective fraction from Ampelopsis Radix with anti-dengue virus activities in vitro and in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Dengue virus (DENV) infection is a global public health issue without effective therapeutic interventions. Chinese medicine with heat-clearing and detoxifying properties has been frequently used in the treatment of viral infection. Ampelopsis Radix (AR) is a traditional Chinese medicine for clearing heat and detoxification that has been widely used in the prevention and treatment of infectious diseases. However, no studies on the effects of AR against viral infection have been reported, thus far. AIM OF THE STUDY: To explore the anti-DENV activities of the fraction (AR-1) obtained from AR both in vitro and in vivo. MATERIALS AND METHODS: The chemical composition of AR-1 was identified by liquid chromatography-tandem MS (LC‒MS/MS). The antiviral activities of AR-1 were studied in baby hamster kidney fibroblast BHK-21 cells, ICR suckling mice and induction of interferon α/ß (IFN-α/ß) and IFN-γ R-/- (AG129) mice. RESULTS: Based on LC‒MS/MS analysis, 60 compounds (including flavonoids, phenols, anthraquinones, alkaloids and other types) were tentatively characterized from AR-1. AR-1 inhibited the cytopathic effect, the production of progeny virus and the synthesis of viral RNA and proteins by blocking DENV-2 binding to BHK-21 cells. Moreover, AR-1 significantly attenuated weight loss, decreased clinical scores and prolonged the survival of DENV-infected ICR suckling mice. Critically, the viral load in blood, brain and kidney tissues and the pathological changes in brain were remarkably alleviated after AR-1 treatment. Further study on AG129 mice showed that AR-1 obviously improved the clinical manifestations and survival rate, reduced viremia, attenuated gastric distension and relieved the pathological lesions caused by DENV. CONCLUSIONS: In summary, this is the first report that AR-1 exhibits anti-DENV effects both in vitro and in vivo, which suggests that AR-1 may be developed as a therapeutic candidate against DENV infection.

Exploring the Therapeutic Potential of Ampelopsis grossedentata Leaf Extract as an Anti-Inflammatory and Antioxidant Agent in Human Immune Cells.

Inflammation is a vital protective response to threats, but it can turn harmful if chronic and uncontrolled. Key elements involve pro-inflammatory cells and signaling pathways, including the secretion of pro-inflammatory cytokines, NF-κB, reactive oxygen species (ROS) production, and the activation of the NLRP3 inflammasome. Ampelopsis grossedentata, or vine tea, contains dihydromyricetin (DHM) and myricetin, which are known for their various health benefits, including anti-inflammatory properties. Therefore, the aim of this study is to assess the impact of an extract of A. grossedentata leaves (50 µg/mL) on inflammation factors such as inflammasome, pro-inflammatory pathways, and macrophage polarization, as well as its antioxidant properties, with a view to combating the development of low-grade inflammation. Ampelopsis grossedentata extract (APG) significantly decreased ROS production and the secretion of pro-inflammatory cytokines (IFNγ, IL-12, IL-2, and IL-17a) in human leukocytes. In addition, APG reduced LPS/IFNγ -induced M1-like macrophage polarization, resulting in a significant decrease in the expression of the pro-inflammatory cytokines TNF-α and IL-6, along with a decrease in the percentage of M1 macrophages and an increase in M0 macrophages. Simultaneously, a significant decrease in NF-κB p65 phosphorylation and in the expression of inflammasome genes (NLRP3, IL-1ß and Caspase 1) was observed. The results suggest that Ampelopsis grossedentata could be a promising option for managing inflammation-related chronic diseases. Further research is needed to optimize dosage and administration methods.

Study on effects of processing technology and storage on the composition of Ampelopsis grossedentata by untargeted metabolomics.

Ampelopsis grossedentata is a traditional medicinal and edible plant rich in bioactive compounds. This paper focus on the white powder on the surface of A. grossedentata, and the effects of processing technology and storage time on the composition of bioactive compounds in Ampelopsis grossedentata extracts (AMP). 33 compounds in AMP were identified and 30 compounds were reported for the first time compared with standards by UHPLC-Q-Orbitrap-MS. Organic acid, phenol, and flavonoids were detected in powder samples. Through comparing the mass spectrum data of three processing samples (traditional method, fermentation and drying-only), five compounds in fermentation samples were higher than other groups, and the content of most compounds of the traditional process was decreased compared with drying-only process. For the storage time research, the powder on the surface was found to be more unstable than leaf parts after 24 h, suggesting that sealing preservation is crucial in the process after powder precipitation.

[Mechanism of total flavonoids from Ampelopsis grossedentata against gouty arthritis based on multi-level interactive network and in vivo experimental validation].

The present study investigated the mechanism of total flavonoids from Ampelopsis grossedentata(AGTF) against gouty arthritis(GA) by network pharmacology and experimental validation. The main active ingredients and targets of AGTF, as well as disease targets, were screened out using relevant databases and literature data. The "protein-protein interaction"(PPI) network and "drug-ingredient-target-pathway" network were constructed, and the potential targets and mechanism of AGTF against GA were predicted. The hyperuricemia(HUA) combined with GA model was induced in rats. The gait behaviors of rats were scored, and ankle swelling degree was observed. The uric acid(UA) level and xanthine oxidase(XOD) activity in the rat serum were detected, and the levels of interleukin-1ß(IL-1ß), interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α) were measured. The protein expression of toll-like receptor 4(TLR4), myeloid differentiation factor 88(MyD88), and nuclear factor-kappa B(NF-κB) in the synovial tissues of the rat ankle joint was determined by immunohistochemistry. Ten active ingredients of AGTF and 73 candidate targets of AGTF against GA were screened out by network pharmacology. Eighty-six signaling pathways were enriched, including TNF signaling pathway, NF-κB signaling pathway, TLR signaling pathway, Nod-like receptor signaling pathway, and purine metabolism signaling pathway, which were closely related to AGTF against GA. Animal experimental results showed that AGTF could effectively improve the abnormal gait behaviors of GA rats, relieve ankle inflammation, and reduce ankle joint swelling. In addition, AGTF could significantly reduce UA level, inhibit XOD activity, decrease TNF-α, IL-6, and IL-1ß content, and down-regulate the expression of TLR4, MyD88, and NF-κB in ankle synovial tissues(P<0.05, P<0.01). The results of network pharmacology and experimental validation are consistent, indicating that AGTF exerts its therapeutic effect on GA by regulating UA metabolism, improving abnormal UA level, reducing the release of inflammatory factors, and regulating immunity and the TLR4/MyD88/NF-κB inflammatory pathway.

Anti-inflammatory Effects of Ampelopsis Japonica Root on Contact Dermatitis in Mice.

OBJECTIVE: To investigate the anti-inflammatory potential of Ampelopsis japonica on contact dermatitis (CD). METHODS: A total of 38 Balb/c mice were divided into 5 groups by using a random number table: normal mice (n=6), CD model mice (n=8), CD mice treated with 3 or 30 mg/kg of the ethanol extract of A. japonica (EEAJ, n=8) and 7.5 mg/kg dexamethasone treated CD mice (DEX, n=8). CD was induced using topical application of 1-fluoro-2,4-dinitrofluorobenzene in mice. EEAJ and DEX were topically applied to the shaved skin of each mouse for 6 days, and the effects of EEAJ and DEX on skin lesions and color, histopathological abnormalities such as epidermal hyperplasia and immune cell infiltration, and tumor necrosis factor (TNF)-α, interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) production were investigated. The effects on changes in body weights and spleen/body weight ratio were also investigated. RESULTS: EEAJ at 30 mg/kg significantly prevented scaling, erythema and enlargement of skin weight compared to using carbon dioxide. EEAJ also prevented epithelial hyperplasia and immune cell infiltrations induced by repeated application of DNFB (P<0.01). In addition, EEAJ significantly lowered levels of TNF-α, IL-6 and MCP-1 (P<0.05 or P<0.01). The anti-inflammatory effects of EEAJ were similar to those of DEX. CONCLUSION: A. japonica may be a new therapeutic agent with the potential to reduce or replace corticosteroids and its mechanisms are closely related to regulation of TNF-α production.

Vine Tea (Ampelopsis grossedentata) Extract Attenuates CCl4 -Induced Liver Injury by Restoring Gut Microbiota Dysbiosis in Mice.

SCOPE: Vine tea (Ampelopsis grossedentata), a traditional Chinese tea, has displayed various biological activities. The authors aim to investigate the effect of Vine Tea (Ampelopsis grossedentata) extract (VTE) on carbon tetrachlorid (CCl4 )induced acute liver injury (ALI) in mice and to explore the underlying role of gut microbiota during the treatment. METHODS AND RESULTS: C57BL/6J mice injected with CCl4 are treated with VTE for 6 weeks. By using H&E staining, immunofluorescence staining, quantitative real-time (qRT)-PCR, and western blot, it is shown that VTE treatment significantly ameliorates hepatocyte necrosis, alleviates the mRNA levels of toll-like receptor 4 (Tlr4), interleukin (Il)-6, inducible nitric oxide synthase (iNOS), acetyl-CoA carboxylase 1 (Acc1), and increases the mRNA levels of peroxisome proliferator-activated receptor gamma (Ppar-γ) and 3-hydroxy-3-methylglutaryl coenzyme A reductase (Hmg-coar) compared to the CCl4 group. Also, VTE abrogates the decreased mRNA expressions of zonula occludens-1 (Zo-1), Occludin, and Mucin1 in colon tissues. Using microbial 16S rDNA sequencing, VTE treatment significantly downregulates the abundances of some harmful intestinal bacteria like Helicobacter and Oscillibacter. In contrast, VTE upregulates the contents of several beneficial bacteria, such as Ruminococcaceae_UCG-014 and Eubacterium_fissicatena_group. Further, VTE fails to improve ALI in the mice with gut microbiota depletion using antibiotic treatment. CONCLUSIONS: The studies suggest that VTE exhibits a protective effect against CCl4 -induced ALI in mice by alleviating hepatic inflammation, suppressing intestinal epithelial barrier injury, and restoring gut microbiota dysbiosis.

Effects of dietary supplementation with Ampelopsis grossedentata extract on production performance and body health of hens.

To investigate the potential of Ampelopsis grossedentata extract used as a feed additive, laying performance, egg quality, yolk cholesterol, plasma biochemical parameters, intestinal histology, and gut microbiota of hens (n = 60) were determined between basal diet (CK) and dietary supplementation with A. grossedentata extract (RT) for 11 weeks. The laying rate in RT group was 6.3 percentage points higher than in CK group together with feed conversion rate decreasing. Significant upregulation of immunoglobulin indexes and downregulation of lipid-related indexes in RT group were also found in comparison with CK group, suggesting that dietary supplementation with A. grossedentata extract benefited in immunity enhancing and blood-fat depressing. Meanwhile, the villus height in duodenum and villus height to crypt depth ratio in duodenum and jejunum of RT group were significantly higher than that of CK group, indicating that dietary supplementation with A. grossedentata extract facilitated nutrient adsorption via intestinal histology changing. Moreover, the richness, diversity, and composition of gut microbiota in RT group significantly altered with a comparison of CK group, including beneficial bacterium and pathogenic bacterium, revealing that dietary supplementation with A. grossedentata extract could modify gut microbiota communities to affect intestinal adsorption and pathogen invasion. In addition, the lipid metabolism-related insulin signing pathway was significantly enriched by gut microbiota in RT group, which were conducive to egg production elevation via facilitating blood lipid amelioration and insulin resistance alleviation. These results provided a basis for A. grossedentata extract served as a feed additive in the hen industry.

Anti-inflammatory Effects of Ampelopsis Japonica Root on Contact Dermatitis in Mice / 中国结合医学杂志

OBJECTIVE@#To investigate the anti-inflammatory potential of Ampelopsis japonica on contact dermatitis (CD).@*METHODS@#A total of 38 Balb/c mice were divided into 5 groups by using a random number table: normal mice (n=6), CD model mice (n=8), CD mice treated with 3 or 30 mg/kg of the ethanol extract of A. japonica (EEAJ, n=8) and 7.5 mg/kg dexamethasone treated CD mice (DEX, n=8). CD was induced using topical application of 1-fluoro-2,4-dinitrofluorobenzene in mice. EEAJ and DEX were topically applied to the shaved skin of each mouse for 6 days, and the effects of EEAJ and DEX on skin lesions and color, histopathological abnormalities such as epidermal hyperplasia and immune cell infiltration, and tumor necrosis factor (TNF)-α, interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) production were investigated. The effects on changes in body weights and spleen/body weight ratio were also investigated.@*RESULTS@#EEAJ at 30 mg/kg significantly prevented scaling, erythema and enlargement of skin weight compared to using carbon dioxide. EEAJ also prevented epithelial hyperplasia and immune cell infiltrations induced by repeated application of DNFB (P<0.01). In addition, EEAJ significantly lowered levels of TNF-α, IL-6 and MCP-1 (P<0.05 or P<0.01). The anti-inflammatory effects of EEAJ were similar to those of DEX.@*CONCLUSION@#A. japonica may be a new therapeutic agent with the potential to reduce or replace corticosteroids and its mechanisms are closely related to regulation of TNF-α production.

Diversity and chemical fingerprinting of endo-metabolomes from endophytes associated with Ampelopsis grossedentata (Hand.-Mazz.) W. T. Wang possessing antibacterial activity against multidrug resistant bacterial pathogens.

BACKGROUND: Serious infections caused by bacteria and their resistance to antibiotics are one of the biggest healthcare threats to mankind. Therefore, the present study aimed to isolate endophytes from medicinal plant Ampelopsis grossedentata, an endemic species of Western Hubei, China and to investigate its antibacterial efficacy and chemical diversity of the secondary metabolites. METHODS: The antibacterial potential of the endophytes was evaluated by disc diffusion method against a panel of eleven type strains and some multidrug resistant pathogenic bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were estimated by broth microdilution using iodonitrotetrazolium chloride assay. Further, the chemical diversity of the metabolites was estimated using LC-Q-TOF-MS/MS and GC-MS fingerprinting. RESULTS: Four endophytic fungi were isolated from the tender shoot of A. grossedentata; they were identified as Fusarium graminearum TC-1, Phomopsis mali TC-3, Pestalotiopsis maculans TC-5 and Alternaria alternata TC-11. Among the endophytes screened, A. alternata TC-11 exhibited significant antibacterial activity with the zones of inhibition ranging from 13.72 ± 0.30 to 21.76 ± 0.53 mm against all the tested type strains and multidrug resistant bacterial pathogens. Further, it showed significant antibacterial activity with MIC values ranging from 0.37 to 3.00 µg/mL. The combined LC-Q-TOF-MS/MS and GC-MS analyses of active extract revealed that alternarian acid, altertenuol, dimethyl sulfone, docosane, dodecane, duclauxin, ergosta-4,6,8(14),22-tetraen-3-one, ethyl 6-cyano-5-oxo-1-phenyl-7-thiophen-2-yl-[1,2,4]triazolo[4,3-a]pyrimidine-3-carboxylate, heptacosane, linoleic acid, neodecanoic acid, oxiranylmethyl ester, pentadecane, verrulactone E, 2,6,11-Trimethyldodecane and 4-[(E,4R,6R)-11-(furan-3-yl)-6-hydroxy-4,8-dimethylundec-8-enyl]-2-hydroxy-2H-furan-5-one were the most abundant compounds present which were responsible for the significant antibacterial activity. CONCLUSIONS: To our knowledge, this is the first report of fungal endophytes isolated from the tender shoot of A. grossedentata with bacteriostatic and bactericidal activities. Our finding provides a new insight into the antibacterial potential of endophytes and envisages the possibility of using them for drug discovery.

Exploring the genes involved in biosynthesis of dihydroquercetin and dihydromyricetin in Ampelopsis grossedentata.

Dihydroquercetin (DHQ), an extremely low content compound (less than 3%) in plants, is an important component of dietary supplements and used as functional food for its antioxidant activity. Moreover, as downstream metabolites of DHQ, an extremely high content of dihydromyricetin (DHM) is up to 38.5% in Ampelopsis grossedentata. However, the mechanisms involved in the biosynthesis and regulation from DHQ to DHM in A. grossedentata remain unclear. In this study, a comparative transcriptome analysis of A. grossedentata containing extreme amounts of DHM was performed on the Illumina HiSeq 2000 sequencing platform. A total of 167,415,597 high-quality clean reads were obtained and assembled into 100,584 unigenes having an N50 value of 1489. Among these contigs, 57,016 (56.68%) were successfully annotated in seven public protein databases. From the differentially expressed gene (DEG) analysis, 926 DEGs were identified between the B group (low DHM: 210.31 mg/g) and D group (high DHM: 359.12 mg/g) libraries, including 446 up-regulated genes and 480 down-regulated genes (B vs. D). Flavonoids (DHQ, DHM)-related DEGs of ten structural enzyme genes, three myeloblastosis transcription factors (MYB TFs), one basic helix-loop-helix (bHLH) TF, and one WD40 domain-containing protein were obtained. The enzyme genes comprised three PALs, two CLs, two CHSs, one F3'H, one F3'5'H (directly converts DHQ to DHM), and one ANS. The expression profiles of randomly selected genes were consistent with the RNA-seq results. Our findings thus provide comprehensive gene expression resources for revealing the molecular mechanism from DHQ to DHM in A. grossedentata. Importantly, this work will spur further genetic studies about A. grossedentata and may eventually lead to genetic improvements of the DHQ content in this plant.

Flavonoids in Ampelopsis grossedentata as covalent inhibitors of SARS-CoV-2 3CLpro: Inhibition potentials, covalent binding sites and inhibitory mechanisms.

Coronavirus 3C-like protease (3CLpro) is a crucial target for treating coronavirus diseases including COVID-19. Our preliminary screening showed that Ampelopsis grossedentata extract (AGE) displayed potent SARS-CoV-2-3CLpro inhibitory activity, but the key constituents with SARS-CoV-2-3CLpro inhibitory effect and their mechanisms were unrevealed. Herein, a practical strategy via integrating bioactivity-guided fractionation and purification, mass spectrometry-based peptide profiling and time-dependent biochemical assay, was applied to identify the crucial constituents in AGE and to uncover their inhibitory mechanisms. The results demonstrated that the flavonoid-rich fractions (10-17.5 min) displayed strong SARS-CoV-2-3CLpro inhibitory activities, while the constituents in these fractions were isolated and their SARS-CoV-2-3CLpro inhibitory activities were investigated. Among all isolated flavonoids, dihydromyricetin, isodihydromyricetin and myricetin strongly inhibited SARS-CoV-2 3CLpro in a time-dependent manner. Further investigations demonstrated that myricetin could covalently bind on SARS-CoV-2 3CLpro at Cys300 and Cys44, while dihydromyricetin and isodihydromyricetin covalently bound at Cys300. Covalent docking coupling with molecular dynamics simulations showed the detailed interactions between the orthoquinone form of myricetin and two covalent binding sites (surrounding Cys300 and Cys44) of SARS-CoV-2 3CLpro. Collectively, the flavonoids in AGE strongly and time-dependently inhibit SARS-CoV-2 3CLpro, while the newly identified SARS-CoV-2 3CLpro inhibitors in AGE offer promising lead compounds for developing novel antiviral agents.

Highly Crystalline Covalent Organic Frameworks Act as a Dual-Functional Fluorescent-Sensing Platform for Myricetin and Water, and Adsorbents for Myricetin.

Selective detection of active ingredients in complex samples has always been a crucial challenge because there are many disturbing compounds, especially structural analogues that interfere with the detection. In this work, a fluorescent covalent organic framework (named COF-TD), which can be used for the selective fluorescence detection and enrichment of myricetin from complex samples, was reported for the first time. The highly crystalline COF-TD with bright blue fluorescence was formed through a solution polymerization method by the condensation reaction between 4,4',4″-(1,3,5-triazine-2,4,6-triyl)trianiline and 2,5-dihydroxy-1,4-benzenedicarboxaldehyde. Due to spatial size selectivity, multisites hydrogen bonding, and π-π interaction, myricetin can quench the fluorescence of COF-TD with an inner filter effect (IFE) and static quenching mechanisms as well as can be enriched on COF-TD. Myricetin can observably eliminate the interference of other compounds and selectively quench the fluorescence of COF-TD with a limit of detection (LOD) of 0.30 µg·mL-1. The high adsorption ability of COF-TD (Q = 124.6 mg·g-1) to myricetin was also obtained. Finally, a sensing platform based on COF-TD for myricetin was successfully developed and applied for the detection of myricetin from vine teas. In addition, COF-TD also showed good water sensing ability and could be used effectively to detect water content in organic solvent (1-18% water in acetone, 0.5-5% water in acetonitrile, 1-4.5% water in ethyl acetate, v/v). To the best of our knowledge, this is the first report where COF-TD was used to detect water in a relatively wide concentration range. In all, this work provided dual-functional fluorescent COFs with the properties of an adsorbent, opening up new methodologies for the simple, selective, and enrichment detection method for myricetin.

Total flavone extract from Ampelopsis megalophylla induces apoptosis in the MCF­7 cell line.

Ampelopsis megalophylla has been found to demonstrate anticancer activities in human cancer cells; however, the effect of total flavone extract (TFE), commonly used in Traditional Chinese Medicine, remains unclear. Furthermore, there is limited information on its effects on breast cancer cell lines. The present study aimed to investigate the inhibitory effects of TFE in different human cancer cell lines. In addition, the underlying mechanisms and the signaling pathways involved were also investigated by determining tumor cell morphological changes, and differences in the cell cycle, apoptosis, mitochondrial transmembrane potential, and related protein expression levels in a breast cancer cell line. It was found that TFE inhibited proliferation in seven cancer cell lines (HeLa, A549, MCF­7, HepG2, A2780, SW620 and MDA­MB­231 and demonstrated a strong inhibitory effect on MCF­7 cell proliferation. Cell morphological changes were also observed and arrested at the G2/M phase following treatment with TFE at different concentrations. In addition, TFE disrupted the mitochondrial membrane potential and upregulated the expression level of apoptotic proteins, including caspase­3, ­8 and ­9, the Bax/Bcl­2 ratio, and Apaf­1 in time­dependent manner. These results indicated that TFE induced apoptosis of the MCF­7 cells via a mitochondrial­mediated apoptotic pathway. In conclusion, TFE is potentially effective in treating breast cancer.

Mechanism and antibacterial activity of vine tea extract and dihydromyricetin against Staphylococcus aureus.

Vine tea (Ampelopsis grossedentata) has been approved as a new food ingredient in 2013. Both vine tea extract (VTE) and its active ingredient, 2R, 3R-Dihydromyricetin (DMY), showed good antibacterial activity. The mechanism of VTE and DMY against Staphylococcus aureus were evaluated by morphology observation, cell membrane and wall assay, protein assay, and DNA assay in this study. The results of SEM and TEM revealed that the VTE and DMY changed the morphology of S. aureus. The leakage of AKPase and ß-galactosidase in treated groups demonstrated that the membrane integrity of S. aureus was disrupted. Meanwhile, the results of protein assay showed that VTE and DMY inhibited the expression of total proteins, and decreased activities of a few energy metabolism enzymes, total ATPase. Moreover, spectral and competitive analysis revealed that VTE and DMY interacted with DNA by groove and intercalation binding. Finally, the suspension experiments of Chinese cabbage and barley showed that inhibitors had strong inhibitory effect on bacteria growth. Overall, the results suggested that VTE and DMY may be potential food preservatives for inhibiting pathogen.