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.

Recent advances on pharmacological effect and safety of Ampelopsis grossedentata / 中国药房

Ampelopsis grossedentata as a traditional medicinal plant， has many pharmacological effects. Pharmacological effects and possible mechanisms are summarized in this paper based on the research progress of A. grossedentata at home and abroad in recent years， involving digestive system （treating liver injury and improving intestinal flora imbalance）， endocrine system （treating hyperglycemia， hyperlipidemia and hyperuricemia）， cardiovascular system （treating hypertension， vascular injury， myocardial ischemia-reperfusion injury and myocardial hypertrophy）， immune system （anti-inflammatory and anti-tumor） and nervous system （adjuvant treatment for chronic degenerative diseases）. By summarizing the animal acute toxicity test， long-term toxicity test and cell test results of A. grossedentata in the literature， it is confirmed that its safety is good.

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.

The Anti-Adiposity Mechanisms of Ampelopsin and Vine Tea Extract in High Fat Diet and Alcohol-Induced Fatty Liver Mouse Models.

Ampelopsis grossedentata (AG) is an ancient medicinal plant that is mainly distributed and used in southwest China. It exerts therapeutic effects, such as antioxidant, anti-diabetic, and anti-inflammatory activities, reductions in blood pressure and cholesterol and hepatoprotective effects. Researchers in China recently reported the anti-obesity effects of AG extract in diet-induced obese mice and rats. To verify these findings, we herein investigated the effects of AG extract and its principal compound, ampelopsin, in high-fat diet (HFD)- and alcohol diet-fed mice, olive oil-loaded mice, and differentiated 3T3-L1 cells. The results obtained showed that AG extract and ampelopsin significantly suppressed increases in the weights of body, livers and abdominal fat and also up-regulated the expression of carnitine palmitoyltransferase 1A in HFD-fed mice. In olive oil-loaded mice, AG extract and ampelopsin significantly attenuated increases in serum triglyceride (TG) levels. In differentiated 3T3-L1 cells, AG extract and ampelopsin promoted TG decomposition, which appeared to be attributed to the expression of hormone-sensitive lipase. In alcohol diet-fed mice, AG extract and ampelopsin reduced serum levels of ethanol, glutamic oxaloacetic transaminase (GOT), and glutamic pyruvic transaminase (GPT) and liver TG. An examination of metabolic enzyme expression patterns revealed that AG extract and ampelopsin mainly enhanced the expression of aldehyde dehydrogenase and suppressed that of cytochrome P450, family 2, subfamily e1. In conclusion, AG extract and ampelopsin suppressed diet-induced intestinal fat accumulation and reduced the risk of fatty liver associated with HFD and alcohol consumption.

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.

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.

Flavor compounds in Vine Tea (Ampelopsis grossedentata) infusions.

Vine tea (Ampelopsis grossedentata) is a tea traditionally used in Chinese herbal medicine that is rich in the natural antioxidant dihydromyricetin (ampelopsin). In addition to its multiple health benefits, vine tea extracts and dihydromyricetin have been suggested as potential natural antioxidants for food applications, such as soybean oil and meat products. However, there is still little information available on vine tea chemistry, and in particular the volatile profile and sensory characteristics, which can affect product acceptability and restrict its use as a natural antioxidant. The objective of this exploratory study was to identify potential volatile components present in vine tea in order to support further research and applications in the food industry. Vine tea infusions brewed from commercial samples were characterized by acidic pH values and a dark, reddish-yellow color. Twenty-one volatile compounds were identified as potential flavor components of vine tea, including aldehydes and ketones. Further studies are suggested to quantify the volatile compounds and understand their importance to vine tea's aroma profile. Sensory studies are also suggested to access consumer's acceptability of vine tea and products containing vine tea as an ingredient.

Evaluation of antioxidant properties of the different tissues of vine tea (Ampelopsis grossedentata) in stripped canola oil and sunflower oil.

The leaves of Ampelopsis grossedentata have a long history of use as a health tea and herbal medicine. Data on the distribution of active metabolites in, and antioxidant capacities of, different vine tea tissues remain incomplete. The aim of this work was to investigate the content of metabolites from A. grossedentata different tissues and evaluate the antioxidant capacities of the extraction of the species in vitro and in oil systems: canola oil and sunflower oil. To evaluate the degree of lipid oxidation, the peroxide value (POV) and thiobarbituric acid-reactive substance value (TBARS) were determined, and proton nuclear magnetic resonance (1 H-NMR) was performed. The results revealed a high total flavonoid content in each of the four extractions (>580 mg/g dried weigh). Leaf extractions exhibited higher antioxidant ability, followed by fruit extract and butylated hydroxytoluene (BHT). The POVs of oils bearing extracts of A. grossedentata and BHT maintained less than 21.08 meq/kg oil against to control with 1,406.33 ± 52.63 meq/kg oil on day 32 in canola oil, and 27.87 meq/kg oil comparing to 1,892.96 ± 48.63 meq/kg oil in control on day 24 in sunflower oil. Concurring results were also obtained in TBARS and 1 H-NMR analysis. Our results indicated that these different tissues of A. grossedentata could be a potential antioxidant resource, and this work may contribute to the comprehensive utilization of this species. PRACTICAL APPLICATION: Leaf extracts of Ampelopsis grossedentata showed effective antioxidant properties, followed by the fruit extract, which showed similar activity to that of the synthetic antioxidant of BHT. Moreover, the investigation of different tissues within the plant may contribute to the comprehensive utilization of this species.

Systems pharmacology approach reveals the antiinflammatory effects of Ampelopsis grossedentata on dextran sodium sulfate-induced colitis.

AIM: To investigate the protective effects of Ampelopsis grossedentata (AMP) on dextran sulfate sodium (DSS)-induced colitis in mice based on systems pharmacology approach. METHODS: Systems pharmacology approach was used to predict the active ingredients, candidate targets and the efficacy of AMP on ulcerative colitis (UC) using a holistic process of active compound screening, target fishing, network construction and analysis. A DSS-induced colitis model in C57BL/6 mice (n = 10/group) was constructed and treated with 5-aminosalicylic acid (100 mg/kg/d) and AMP (400 mg/kg/d) to confirm the underlying mechanisms and effects of AMP on UC with western blot analyses, polymerase chain reaction, histological staining and immunohistochemistry. RESULTS: The therapeutic effects of AMP against DSS-induced colitis were determined in the beginning, and the results showed that AMP significantly improved the disease in general observations and histopathology analysis. Subsequent systems pharmacology predicted 89 corresponding targets for the four candidate compounds of AMP, as well as 123 candidate targets of UC, and protein-protein interaction networks were constructed for the interaction of putative targets of AMP against UC. Enrichment analyses on TNF-α and RANKL/RANK, a receptor activator of NF-κB signaling pathways, were then carried out. Experimental validation revealed that inflammation-related signaling pathways were activated in the DSS group, and AMP significantly suppressed DSS-induced high expression of IRAK1, TRAF6, IκB and NF-κB, and inhibited the elevated expression levels of TNF-α, IL-1ß, IL-6 and IL-8. CONCLUSION: AMP could exert protective effects on UC via suppressing the IRAK1/TRAF6/NF-κB-mediated inflammatory signaling pathways.

Research progress on antibacterial effects of Ampelopsis grossedentata / 中草药

In recent years, researches on the antibacterial experiments of single herb, extracts, monomer ingredients and the compound preparations have confirmed that a variety of Chinese meteria medica have good antibacterial effects, and they are not easily produced drug resistance. Ampelopsis grossedentata, which can be used as medicine and food, contains various biological ingredients. Among them, flavonoids have desired antibacterial effect and synergistic effect when combined with antibiotics. In this review, antibacterial effects of A. grossedentata were summarized from domestic and foreign study literatures in the recent decade, including the main antibacterial components, the antimicrobial effects, and mechanism of this medicinal plant, aming to provide reference for the studies on the physiological and pharmacological functions, clinical application, and product development of A. grossedentata.

Optimization of the Ultrasonic-Assisted Extraction of Bioactive Flavonoids from Ampelopsis grossedentata and Subsequent Separation and Purification of Two Flavonoid Aglycones by High-Speed Counter-Current Chromatography.

The fermented leaf of Ampelopsis grossedentata has been used as a beverage and folk medicine called "vine tea" in the southern region of China. In this paper, the optimum extraction conditions for the maximum recovery amounts of total flavonoids (TF), dihydromyricetin (DMY), myricitrin (MYG) and myricetin (MY) from natural Ampelopsis grossedentata leaves subjected to ultrasonic-assisted extraction (UAE) were determined and optimized by using response surface methodology. The method was employed by the Box-Behnken design (BBD) and Derringer's desirability function using methanol concentration, extraction time, liquid/solid ratio as factors and the contents of TF, DMY, MYG and MY as responses. The obtained optimum UAE conditions were as follows: a solvent of 80.87% methanol, an extraction time of 31.98 min and a liquid/solid ratio of 41.64:1 mL/g. Through analysis of the response surface, it implied that methanol concentration and the liquid/solid ratio had significant effects on TF, DMY, MYG and MY yields, whereas extraction time had relatively little effects. The established extraction and analytical methods were successfully applied to determine the contents of the total flavonoids and three individual flavonoids in 10 batches of the leaf samples of A. grossedentata from three counties in Fujian Province, China. The results suggested the variability in the quality of A. grossedentata leaves from different origins. In addition, high purities of dihydromyricetin and myricetin were simultaneously separated and purified from the extract subjected to optimized UAE, by high-speed counter-current chromatography using a solvent system of N-hexane-ethyl acetate-methanol-water (1:3:2:4; v/v/v/v). In a single operation, 200 mg of the extract were separated to yield 86.46 mg of dihydromyricetin and 3.61 mg of myricetin with the purity of 95.03% and 99.21%, respectively. The results would be beneficial for further exploiting the herbal products and controlling the quality of the herb and its derived products.

α-Glucosidase inhibition and antihyperglycemic activity of flavonoids from Ampelopsis grossedentata and the flavonoid derivatives.

The dried leaves and stems of Ampelopsis grossedentata have been used as a health tea and herbal medicine for hundreds of years in China. The study was aimed at searching for novel α-glucosidase inhibitors among the richest components of A. grossedentata and their derivatives. Three known major components (1-3) were isolated by recrystallization process and six new derivatives (4-9) were obtained by etherification of the bioactive flavonoid. All compounds were evaluated for their inhibitory activities against α-glucosidase (from Saccharomyces cerevisiae). As a result, compound 9 showed a significant α-glucosidase inhibitory activity with IC50 value of 9.3 µM and acted as a competitive inhibitor with the value of the inhibition constant (Ki) being 10.3 µM. The oral administration of compound 9 at a dose of 50mg/kg significantly reduced the post prandial blood glucose levels of normal and streptozotocin (STZ)-induced diabetic mice. Furthermore, compound 9 significantly decreased the fasting blood glucose levels in STZ-induced diabetic mice.

Determination of dihydromyricetin in rat plasma by LC-MS/MS and its application to a pharmacokinetic study.

Ampelopsis grossedentata (Hand.-Mazz.) W.T. Wang has long been used as a traditional Chinese medicinal herb among the indigenous people in the Yangtze River region of China. Dihydromyricetin (DMY) is the most abundant (approximately 30%) and bioactive constituent in A. grossedentata (Hand.-Mazz.) W.T. Wang, and recent studies have demonstrated its various pharmacological activities. In the present study, a first specific, sensitive, rapid and reliable LC-MS/MS method for the determination of DMY in rat plasma was developed and validated. The plasma samples were prepared with protein precipitation method, and chromatographic separation was performed on a Welch Ultimate XB-C18 column (50 × 2.1 mm, 5 µm) using a gradient elution with water and acetonitrile. The mass spectrometry (MS) analysis was conducted in negative ionization mode with multiple reaction monitoring (MRM) transitions at m/z 319.1→192.8 for DMY and m/z 609.0→301.2 for rutin (IS). The plasma concentration profiles and pharmacokinetic parameters were analyzed after oral administration of dextroisomer and racemate DMY at the dose of 100 mg/kg in rats. The method validation was conducted over the calibration range of 10.0-5000 ng/ml with the intra- and inter-day precision and accuracy within 12.0% (RSD) and 5.6% (RE). The recoveries, matrix effect and stability under different conditions were all proved acceptable. The values of Tmax, AUC(0-∞) and Vd were significantly different between the groups of dextroisomer and racemate DMY (P<0.05), and pharmacokinetic results revealed their poor absorptions into blood, probably high tissue distributions and slow elimination processes. The present study will provide helpful information for the further studies and future clinical applications of DMY.

Supercritical carbon dioxide extraction of bioactive compounds from Ampelopsis grossedentata stems: process optimization and antioxidant activity.

Supercritical carbon dioxide (SC-CO(2)) extraction of bioactive compounds including flavonoids and phenolics from Ampelopsis grossedentata stems was carried out. Extraction parameters such as pressure, temperature, dynamic time and modifier, were optimized using an orthogonal array design of L(9) (3(4)), and antioxidant activities of the extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay and ferrous ion chelating (FIC) assay. The best conditions obtained for SC-CO(2) extraction of flavonoids was 250 bar, 40 °C, 50 min, and with a modifier of methanol/ethanol (1:3, v/v), and that for phenolics extraction was 250 bar, 40 °C, 50 min, and with a modifier of methanol/ethanol (1:1, v/v). Meantime, flavonoids and phenolics were found to be mainly responsible for the DPPH scavenging activity of the extracts, but not for the chelating activity on ferrous ion according to Pearson correlation analysis. Furthermore, several unreported flavonoids such as apigenin, vitexin, luteolin, etc., have been detected in the extracts from A. grossedentata stems.