New natural protein tyrosine phosphatase 1B inhibitors from Gynostemma pentaphyllum.

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease mainly caused by insulin resistance, which can lead to a series of complications such as cardiovascular disease, retinopathy, and its typical clinical symptom is hyperglycaemia. Glucosidase inhibitors, including Acarbose, Miglitol, are commonly used in the clinical treatment of hypoglycaemia. In addition, Protein tyrosine phosphatase 1B (PTP1B) is also an important promising target for the treatment of T2DM. Gynostemma pentaphyllum is a well-known oriental traditional medicinal herbal plant, and has many beneficial effects on glucose and lipid metabolism. In the present study, three new and nine known dammarane triterpenoids isolated from G. pentaphyllum, and their structures were elucidated by spectroscopic methods including HR-ESI-MS,1H and 13C NMR and X-ray crystallography. All these compounds were evaluated for inhibitory activity against α-glucosidase, α-amylase and PTP1B. The results suggested that compounds 7∼10 were potential antidiabetic agents with significantly inhibition activity against PTP1B in a dose-dependent manner.

Dammarane-type triterpenoids from Gynostemma longipes and their protective activities on hypoxia-induced injury in PC12 cells.

Sixteen new dammarane-type triterpenoid saponins (1-16) featuring diverse structural variations in the side chain at C-17, along with twenty-one known analogues (17-37), have been isolated from the rhizomes of Gynostemma longipes C. Y. Wu, a plant renowned for its medicinal and edible properties. The structural elucidation of these compounds was accomplished through comprehensive analyses of 1D and 2D NMR and HRMS spectroscopic data, supplemented by comparison with previously reported data. Subsequent assays on the isolates for their protective effects against hypoxia-induced damage in pheochromocytoma cells (PC12 cells) revealed that nine saponins exhibited significant anti-hypoxic activities. Further investigation into the anti-hypoxia mechanisms of the representative saponins demonstrated that compounds 22 and 36 markedly reduced the levels of hypoxia-induced apoptosis. Additionally, these compounds were found to decrease the release of lactate dehydrogenase (LDH) and malondialdehyde (MDA), while increasing the activity of superoxide dismutase (SOD), thereby indicating that the saponins could mitigate hypoxia-induced injuries by ameliorating apoptosis and oxidative stress. These findings offer substantial evidence for the future utilization and development of G. longipes, identifying dammarane-type triterpenoid saponins as its active anti-hypoxic constituents.

Gypenoside XVII Reduces Synaptic Glutamate Release and Protects against Excitotoxic Injury in Rats.

Excitotoxicity is a common pathological process in neurological diseases caused by excess glutamate. The purpose of this study was to evaluate the effect of gypenoside XVII (GP-17), a gypenoside monomer, on the glutamatergic system. In vitro, in rat cortical nerve terminals (synaptosomes), GP-17 dose-dependently decreased glutamate release with an IC50 value of 16 µM. The removal of extracellular Ca2+ or blockade of N-and P/Q-type Ca2+ channels and protein kinase A (PKA) abolished the inhibitory effect of GP-17 on glutamate release from cortical synaptosomes. GP-17 also significantly reduced the phosphorylation of PKA, SNAP-25, and synapsin I in cortical synaptosomes. In an in vivo rat model of glutamate excitotoxicity induced by kainic acid (KA), GP-17 pretreatment significantly prevented seizures and rescued neuronal cell injury and glutamate elevation in the cortex. GP-17 pretreatment decreased the expression levels of sodium-coupled neutral amino acid transporter 1, glutamate synthesis enzyme glutaminase and vesicular glutamate transporter 1 but increased the expression level of glutamate metabolism enzyme glutamate dehydrogenase in the cortex of KA-treated rats. In addition, the KA-induced alterations in the N-methyl-D-aspartate receptor subunits GluN2A and GluN2B in the cortex were prevented by GP-17 pretreatment. GP-17 also prevented the KA-induced decrease in cerebral blood flow and arginase II expression. These results suggest that (i) GP-17, through the suppression of N- and P/Q-type Ca2+ channels and consequent PKA-mediated SNAP-25 and synapsin I phosphorylation, reduces glutamate exocytosis from cortical synaptosomes; and (ii) GP-17 has a neuroprotective effect on KA-induced glutamate excitotoxicity in rats through regulating synaptic glutamate release and cerebral blood flow.

Gypenoside XLIX alleviates intestinal injury by inhibiting sepsis-induced inflammation, oxidative stress, apoptosis, and autophagy.

Intestinal barrier dysfunction is a significant complication induced by sepsis, yet therapeutic strategies targeting such dysfunction remain inadequate. This study investigates the protective effects of Gypenoside XLIX (Gyp XLIX) against intestinal damage induced by sepsis. Septic intestinal injury in mice was induced by cecum ligation and puncture (CLP) surgery. The biological activity and potential mechanisms of Gyp XLIX were explored through intraperitoneal injection of Gyp XLIX (40 mg/kg). The study demonstrates that Gyp XLIX improves the pathological structural damage of the intestine and increases tight junction protein expression as well as the number of cup cells. Through activation of the nuclear factor erythroid 2-related factor 2 - Kelch-like ECH-associated protein 1 (Nrf2-Keap1) pathway, Gyp XLIX enhances antioxidant enzyme levels while reducing the excessive accumulation of reactive oxygen species (ROS). In addition, Gyp XLIX effectively alleviates sepsis-induced intestinal inflammation by inhibiting the nuclear factor kappa B (NF-κB) pathway and activation of the NLRP3 inflammasome. Moreover, Gyp XLIX inhibits cell death through modifying phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, further enhancing its ability to shield the intestinal barrier. The combined action of these molecular mechanisms promotes the restoration of immune balance and reduces excessive autophagy activity induced under septic conditions. In summary, Gyp XLIX exhibits a significant preventive action against intestinal damage brought on by sepsis, with its mechanisms involving the improvement of intestinal barrier function, antioxidative stress, inhibition of inflammatory response, and cell apoptosis. This research offers a potential strategy for addressing intestinal barrier impairment brought on by sepsis.

Integrative metabolomic and transcriptomic analyses reveals the accumulation patterns of key metabolites associated with flavonoids and terpenoids of Gynostemma pentaphyllum (Thunb.) Makino.

Gynostemma pentaphyllum (Thunb.) Makino (G. pentaphyllum) is a medicinal and edible plant with multiple functions of liver protection, anti-tumor, anti-inflammation, balancing blood sugar and blood lipids. The nutritional value of the G. pentaphyllum plant is mainly due to its rich variety of biologically active substances, such as flavonoids, terpenes and polysaccharides. In this study, we performed a comprehensive analysis combining metabolomics and root, stem and leaf transcriptomic data of G. pentaphyllum. We used transcriptomics and metabolomics data to construct a dynamic regulatory network diagram of G. pentaphyllum flavonoids and terpenoids, and screened the transcription factors involved in flavonoids and terpenoids, including basic helix-loop-helix (bHLH), myb-related, WRKY, AP2/ERF. Transcriptome analysis results showed that among the DEGs related to the synthesis of flavonoids and terpenoids, dihydroflavonol 4-reductase (DFR) and geranylgeranyl diphosphate synthases (GGPPS) were core genes. This study presents a dynamic image of gene expression in different tissues of G. pentaphyllum, elucidating the key genes and metabolites of flavonoids and terpenoids. This study is beneficial to a deeper understanding of the medicinal plants of G. pentaphyllum, and also provides a scientific basis for further regulatory mechanisms of plant natural product synthesis pathways and drug development.

Tumor-targeted gypenoside nanodrug delivery system with double protective layers.

OBJECTIVES: Gypenoside (Gyp) is easily degraded in the gastrointestinal tract, resulting in its low bioavailability. We aimed to develop a tumor-targeted Gyp nanodrug delivery system and to investigate its antitumor effect in vitro. MATERIALS AND METHODS: We used Gyp as the therapeutic drug molecule, mesoporous silica (MSN) and liposome (Lipo) as the drug carrier and protective layers, and aptamer SYL3C as the targeting element to establish a tumor-targeted nanodrug delivery system (i.e., SYL3C-Lipo@Gyp-MSN). The characteristics of SYL3C-Lipo@Gyp-MSN were investigated, and its drug release performance, cell uptake, and antitumor activity in vitro were evaluated. RESULTS: A tumor-targeted Gyp nanodrug delivery system was successfully prepared. The SYL3C-Lipo@Gyp-MSN was spherical or ellipsoidal; had good dispersion, which enabled it to specifically target and kill the liver tumor cell HepG2; and effectively protected the early leakage of Gyp. CONCLUSIONS: We have established a tumor-targeted nanodrug delivery system that can target and kill liver cancer cells and may provide a strategy for preparing new nanodrug-loaded preparations of traditional Chinese medicine.

Genome-wide characterization of the bHLH gene family in Gynostemma pentaphyllum reveals its potential role in the regulation of gypenoside biosynthesis.

BACKGROUND: Gynostemma pentaphyllum, an ancient Chinese herbal medicine, serves as a natural source of gypenosides with significant medicinal properties. Basic helix-loop-helix (bHLH) transcription factors play pivotal roles in numerous biological processes, especially in the regulation of secondary metabolism in plants. However, the characteristics and functions of the bHLH genes in G. pentaphyllum remain unexplored, and their regulatory role in gypenoside biosynthesis remains poorly elucidated. RESULTS: This study identified a total of 111 bHLH members in G. pentaphyllum (GpbHLHs), categorizing them into 26 subgroups based on shared conserved motif compositions and gene structures. Collinearity analysis illustrated that segmental duplications predominately lead to the evolution of GpbHLHs, with most duplicated GpbHLH gene pairs undergoing purifying selection. Among the nine gypenoside-related GpbHLH genes, two GpbHLHs (GpbHLH15 and GpbHLH58) were selected for further investigation based on co-expression analysis and functional prediction. The expression of these two selected GpbHLHs was dramatically induced by methyl jasmonate, and their nuclear localization was confirmed. Furthermore, yeast one-hybrid and dual-luciferase assays demonstrated that GpbHLH15 and GpbHLH58 could bind to the promoters of the gypenoside biosynthesis pathway genes, such as GpFPS1, GpSS1, and GpOSC1, and activate their promoter activity to varying degrees. CONCLUSIONS: In conclusion, our findings provide a detailed analysis of the bHLH family and valuable insights into the potential use of GpbHLHs to enhance the accumulation of gypenosides in G. pentaphyllum.

Gypenoside XIII regulates lipid metabolism in HepG2 hepatocytes and ameliorates nonalcoholic steatohepatitis in mice.

Gypenoside XIII is isolated from Gynostemma pentaphyllum (Thunb.) Makino. In mice, G. pentaphyllum extract and gypenoside LXXV have been shown to improve non-alcoholic steatohepatitis (NASH). This study investigated whether gypenoside XIII can regulate lipid accumulation in fatty liver cells or attenuate NASH in mice. We used HepG2 hepatocytes to establish a fatty liver cell model using 0.5 mM oleic acid. Fatty liver cells were treated with different concentrations of gypenoside XIII to evaluate the molecular mechanisms of lipid metabolism. In addition, a methionine/choline-deficient diet induced NASH in C57BL/6 mice, which were given 10 mg/kg gypenoside XIII by intraperitoneal injection. In fatty liver cells, gypenoside XIII effectively suppressed lipid accumulation and lipid peroxidation. Furthermore, gypenoside XIII significantly increased SIRT1 and AMPK phosphorylation to decrease acetyl-CoA carboxylase phosphorylation, reducing fatty acid synthesis activity. Gypenoside XIII also decreased lipogenesis by suppressing sterol regulatory element-binding protein 1c and fatty acid synthase production. Gypenoside XIII also increased lipolysis and fatty acid ß-oxidation by promoting adipose triglyceride lipase and carnitine palmitoyltransferase 1, respectively. In an animal model of NASH, gypenoside XIII effectively decreased the lipid vacuole size and number and reduced liver fibrosis and inflammation. These findings suggest that gypenoside XIII can regulate lipid metabolism in fatty liver cells and improve liver fibrosis in NASH mice. Therefore, gypenoside XIII has potential as a novel agent for the treatment of NASH.

New dammarane-type triterpenoids from hydrolyzate of total Gynostemma pentaphyllum saponins with protein tyrosine phosphatase 1B inhibitory activity.

Protein tyrosine phosphatase 1B (PTP1B) is a key factor and regulator of glucose, lipid metabolism throughout the body, and a promising target for treatment of type 2 diabetes mellitus (T2DM). Gynostemma pentaphyllum is a famous oriental traditional medicinal herbal plant and functional food, which has shown many beneficial effects on glucose and lipid metabolism. The aim of the present study is to assess the inhibitory activity of five new and four known dammarane triterpenoids isolated from the hydrolysate product of total G. pentaphyllum saponins. The bioassay data showed that all the compounds exhibited significant inhibitory activity against PTP1B. The structure-activity relationship showed that the strength of PTP1B inhibitory activity was mainly related to the electron-donating group on its side chain. Molecular docking analysis suggested that its mechanism may be due to the formation of competitive hydrogen bonding between the electron-donating moiety and the Asp48 amino acid residues on the PTP1B protein.

Dammarane-type saponins from Gynostemma pentaphyllum and their anti-aging activities via up-regulating mitochondria related proteins.

The importance of mitochondria in regulation of aging has been extensively recognized and confirmed. Gynostemma pentaphyllum (Thunb.) Makino, a homology of medicine and food, has been widely utilized as dietary supplement. In this study, the transcriptome of normal cells (wild type mouse embryo fibroblasts) regulated by the 30% aqueous EtOH extract of G. pentaphyllum was firstly evaluated by RNA sequencing and the results revealed that the G. pentaphyllum could up-regulate the genes involved in oxidative phosphorylation (OXPHOS) and sirtuin (SIRT) signaling pathways, indicating its effect in promoting cell viability might be attributed to the role of improving mitochondrial functions. To further discover the bioactive compounds, sixteen undescribed dammarane-type saponins along with twenty-eight known analogues were isolated from the active extract of G. pentaphyllum. Their structures were elucidated by means of comprehensive analysis of NMR and HRMS spectroscopic data. All isolates were evaluated for the regulatory effects on SIRT3 and translocase of the outer membrane 20 (TOM20), and thirteen of them exhibited satisfactory agonist activities on both SIRT3 and TOM20 at 5 µM. Furthermore, the preliminary structure-activity relationships analysis demonstrated the additional hydroxymethyl and carbonyl groups or less sugar residues in saponins could contribute positively to the up-regulatory effect on SIRT3 and TOM20. These findings encouraged the potential roles of G. pentaphyllum and its bioactive saponins in the development of natural drugs for the treatment of aging-related diseases.

Systematical characterization of gypenosides in Gynostemma pentaphyllum and the chemical composition variation of different origins.

Gynostemma pentaphyllum (Thunb.) Makino is an herbaceous plant of Cucurbitaceae family, which has been widely used as an herbal tea and traditional Chinese medicine. Since its saponins are similar to ginsenosides and have a wide range of activities, it has attracted wide interest. However, there are still a large number of unknown saponins that have not been isolated, especially some trace gypenosides. In the present study, a HILIC × RP offline two-dimensional liquid separation combined with a multimode data acquisition was developed for the systematical characterization of gypenosides. On top of the negative mode information, considering that saponins are prone to in-source fragmentations in positive ion mode, a precursor ion list data acquisition method was used for the targeted acquisition of multistage positive data. Reference herbal drug was taken as a golden sample to probe the chemical composition of G. pentaphyllum. The mixed sample of commercially available samples were also analyzed in parallel. Furthermore, the chemical compositions of commercially available samples from different sources were compared. In total, 1108 saponins were characterized, among which 588 were accurately characterized, with 574 identified in the reference herbal drug and 700 in the mixed commercially available samples. The commercially available samples showed great composition variation. These findings clarified the material basis and provided clues for quality control of G. pentaphyllum.

The Role of Gynostemma pentaphyllum in Regulating Hyperlipidemia.

Developing effective and safe lipid-lowering drugs is highly urgent. This study aims to investigate the effectiveness and underlying mechanisms of Gynostemma pentaphyllum (GP) in the treatment of hyperlipidemia. First, a meta-analysis was performed to determine the lipid-lowering effects of GP. Thereafter, hyperlipidemia was induced in mice using a high-fat diet (HFD) and was subsequently treated with Gynostemma pentaphyllum extract (GPE) by daily gavage for 12 weeks. The body weight, tissue weight, blood lipid level, and liver lipid level were determined. Additionally, mouse serum samples were subjected to metabolomic profiling and feces were collected at different time points for metagenomic analysis via 16S rDNA sequencing. A total of 15 out of 1520 studies were retrieved from six databases. The pooled results of the meta-analysis showed that GP effectively reduced triglyceride levels and increased high-density lipoprotein cholesterol (both [Formula: see text]). Animal experiments revealed that GPE administration significantly reduced body weight, ameliorated high blood lipid levels, limited lipid deposition, and improved insulin resistance. Furthermore, GPE treatment markedly changed the intestinal microbiota structure and constitution of tryptophan metabolites. In conclusion, our results confirm the lipid-lowering effect of GP, which may be partly attributable to regulation of the intestinal microbiota and tryptophan metabolism.

Liver lipidomics analysis reveals the anti-obesity and lipid-lowering effects of gypnosides from heat-processed Gynostemma pentaphyllum in high-fat diet fed mice.

BACKGROUND: In traditional Chinese medicine, Gynostemma pentaphyllum (G. pentaphyllum) is widely used to treat conditions associated with hyperlipidemia, and its therapeutic potential has been demonstrated in numerous studies. However, the mechanism of lipid metabolism in hyperlipidemic by G. pentaphyllum, especially heat-processed G. pentaphyllum is not yet clear. PURPOSE: The aim of this study was to investigate the therapeutic mechanism of gypenosides from heat-processed G. pentaphyllum (HGyp) in hyperlipidemic mice by means of a lipidomics. METHODS: The content of the major components of HGyp was determined by ultra-performance liquid chromatography-electrospray ionization ion trap mass spectrometry (UPLC-ESI-MS). An animal model of hyperlipidaemia was constructed using C57BL/6J mice fed with high-fat diet. HGyp was also administered at doses of 50, 100 and 200 mg/kg, all for 12 weeks. Serum parameters were measured, histological sections were prepared and liver lipidome analysis using UPLC-MS coupled with multivariate statistical analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were used to analyze the genes and proteins associated with lipid lowering in HGyp. RESULTS: HGyp reduced body weight, serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein (LDL) and hepatic lipid accumulation in hyperlipidemic obese mice. To explore specific changes in lipid metabolism in relation to HGyp administration, lipid analysis of the liver was performed. Orthogonal partial least squares discriminant analysis (OPLS-DA) score plots showed that HGyp altered lipid metabolism in HFD mice. In particular, fatty acids (FA), triglycerides (DG), TG and ceramides (CER) were significantly altered. Eleven lipids were identified as potential lipid biomarkers, namely TG (18:2/20:5/18:2), TG (18:2/18:3/20:4), DG (18:3/20:0/0:0), Cer (d18:1/19:0), Cer (d16:1/23:0), Ceramide (d18:1/9Z-18:1), PS (19:0/18:3), PS (20:2/0:0), LysoPC (22:5), LysoPE (0:0/18:0), PE (24:0/16:1). Western blot and qRT-PCR analysis showed that these metabolic improvements played a role by down-regulating genes and proteins related to fat production (SREBP1, ACC1, SCD1), up-regulating genes and proteins related to lipid oxidation (CPTA1, PPARα) and lipid transport decomposition in the bile acid pathway (LXRα, PPARγ, FXR, BSEP). CONCLUSION: The lipid-lowering effect of gypenosides from heat-processed G. pentaphyllum is regulate lipid homeostasis and metabolism.

[Determination of gypenoside XLVI and LVI in Gynostemma pentaphyllum from Fujian by ultra-high performance liquid chromatography-charged aerosol detector].

Gynostemma pentaphyllum (Thunb.) Makino contains dammarane-type triterpenoid saponins, similar to ginseng, with a host of pharmacological activities. However, its planting resources and chemical composition are quite complex. The chemical constituents of Gynostemma pentaphyllum vary drastically among different origins and varieties. Thus, the corresponding quality control methods also need to be different. Currently, limited information is available about the quality control of Gynostemma pentaphyllum from Fujian. A new method based on ultra-high performance liquid chromatography-charged aerosol detection (UHPLC-CAD) was established for the determination of gypenoside XLVI and LVI in Gynostemma pentaphyllum. The major components of Gynostemma pentaphyllum were characterized using UHPLC-quadrupole time-of-flight-mass spectrometry (UHPLC-Q-TOF/MS) combined with UHPLC-CAD. The results revealed gypenoside XLVI, LVI, and their corresponding malonyl-containing acidic saponins as the main components. However, malonylgypenoside XLVI and LVI can easily remove their malonyl group and convert to gypenoside XLVI and LVI during the application of Gynostemma pentaphyllum. In this study, the samples were pretreated using alkali hydrolysis to transform the acid saponins completely, and the final contents of gypenoside XLVI and LVI were determined via UHPLC-CAD. The optimal alkaline hydrolysis, extraction, and liquid chromatography conditions were established. First, the alkaline hydrolysis conditions were optimized. The effects of the volume of ammonia and reaction time on the contents of gypenoside XLVI, LVI, malonylgypenoside XLVI, and LVI were examined. Malonylgypenoside XLVI and LVI could be transformed completely to gypenoside XLVI and LVI by standing for 24 h in an ethanol-water-ammonia (50∶46∶4, v/v/v) mixture. Furthermore, the extraction conditions were optimized. Next, effects of the different solvents, extraction time, and solid-liquid ratio on the extraction rates of gypenoside XLVI and LVI were investigated. The extraction method for Gynostemma pentaphyllum powder using the ethanol-water-ammonia (50∶46∶4, v/v/v) and a solid-liquid ratio of 1∶150 (g∶mL) for 30 min was established. Finally, a prepared test solution was separated on a Waters ACQUITY UPLC BEH C18 chromatographic column (100 mm×2.1 mm, 1.7 µm). Acetonitrile and 0.1% (v/v) formic acid aqueous solution were used as the mobile phases for gradient elution. The flow rate was set to 0.5 mL/min and column temperature was maintained at 40 ℃. The separation was detected using a charged aerosol detector. Results indicated that the logarithm of the mass concentrations of gypenoside XLVI and LVI had a linear relationship with the logarithm of the peak area in the range of 9.94-318.00 µg/mL and 12.78-409.00 µg/mL, respectively. The correlation coefficients (r) were 0.9993 and 0.9995, respectively. The limit of detection (LOD) and the limit of quantification (LOQ) of gypenoside XLVI were 1.58 µg/mL and 6.36 µg/mL, respectively. The LOD and LOQ of gypenoside LVI were 2.05 µg/mL and 8.18 µg/mL, respectively. The relative standard deviations (RSDs) of precision, repeatability, and 24 h stability were less than 2.0% (n=6). The spiked recoveries of gypenoside XLVI were 100.2%-107.2% and the RSD value was 2.4%. The spiked recoveries of gypenoside LVI were 97.9%-104.2% and the RSD value was 2.6%. The results of 16 batches of Gynostemma pentaphyllum samples indicated that the gypenoside XLVI content was 0.57%-2.57%, and gypenoside LVI content was 0.66%-2.99%. Hence, this method has high sensitivity and good reproducibility. Therefore, it can be used for quality research and quality control of Gynostemma pentaphyllum from Fujian.

[Components and lipid-lowering effect of total saponins from underground part of Gynostemma pentaphyllum].

The saponins in different parts of Gynostemma pentaphyllum were analyzed via UPLC-Q-TOF-MS~E. A total of 46 saponins were identified, and the underground part had 26 saponins more than the aboveground part, most of which were trisaccharide saponins. The rat model of hyperlipidemia was established with high-fat diet. This study explored the lipid-lowering activity of total saponins in the underground part of G. pentaphyllum, so as to provide a theoretical basis for the comprehensive utilization of the underground part of G. pentaphyllum. A total of 99 healthy SD rats were randomly assigned into a blank group, a model group, a positive drug group, an aboveground total saponins group, and low-, medium-, and high-dose underground total saponins groups. Except the blank group, the other groups were fed with high-fat diet for 6 weeks. Then, the blood was collected from the orbital cavity to determine whether the modeling was successful according to the serum levels of total cholesterol(TC) and triglyceride(TG). After intragastric administration of the corresponding agents for 30 continuous days, the physical state of the rats were observed, and the body weight and liver specific gravity were measured. Furthermore, the levels of TC, TG, low-density lipoprotein cholesterol(LDL-C), high-density lipoprotein cholesterol(HDL-C), alanine transaminase(ALT), aspartate transaminase(AST), bilirubin, and total bile acids in serum, as well as the levels of superoxide dismutase(SOD), malondialdehyde(MDA), peroxidase proliferator-activated receptor(PPAR-γ) in the liver tissue, were determined. The pathological changes of liver was observed via HE staining. The results showed that the aboveground total saponins and medium-and high-dose underground total saponins can treat hepatocyte steatosis, lower TC, TG, LDL-C, ALT, AST, total bilirubin, MDA, and PPAR-γ levels, and increase HDL-C and SOD levels in the model rats. The effect tended to be more obvious with the increase in dosage. Therefore, the total saponins in the underground part of G. pentaphyllum have good pharmacological effect of reducing blood lipid, which provides a theoretical basis for the comprehensive utilization of the underground part of G. pentaphyllum.

Chemical Characterization and Atherosclerosis Alleviation Effects of Gypenosides from Gynostemma pentaphyllum through Ameliorating Endothelial Dysfunction via the PCSK9/LOX-1 Pathway.

Dietary saponins have the potential to ameliorate atherosclerosis (AS). Gypenosides of Gynostemma pentaphyllum (GPs) have been used as functional foods to exhibit antiatherosclerotic activity. The present study aimed to explore the protective effect, underlying mechanism and active substances of GPs on AS in vivo and in vitro. Results demonstrated GPs administration reduced the serum concentrations of TC and LDL-C, upregulated the plasma HDL-C content, inhibited the secretion of ICAM-1, VCAM-1, and MCP-1, and alleviated vascular lesions in VitD3 plus high cholesterol diet-induced AS rats as well as reduced adhesion factors levels in ox-LDL-stimulated HUVECs, which was potentially associated with suppressing PCSK9/LOX-1 pathway. Further activity-guided phytochemical investigation of GPs led to the identification of five new dammarane-type glycosides (1-5) and ten known analogs (6-15). Bioassay evaluation showed compounds 1, 6, 7, 12, 13, and 14 observably reduced the expressions of PCSK9 and LOX-1, as well as the secretion of adhesion factors in injured HUVECs. Molecular docking experiments suggested that the active saponins of GPs might bind to the allosteric pocket of PCSK9 located at the catalytic and C-terminal domains, and 2α-OH-protopanaxadiol-type gypenosides might exert a higher affinity for an allosteric binding site on PCSK9 by hydrogen-bond interaction with ARG-458. These findings provide new insights into the potential nutraceutical application of GPs and their bioactive compounds in the prevention and discovery of novel therapeutic strategies for AS.

Enzymatic Biotransformation of Gypenoside XLIX into Gylongiposide I and Their Antiviral Roles against Enterovirus 71 In Vitro.

Biotransformation of specific saponins in the valuable medical plants to increase their bioavailability and pharmaceutical activities has attracted more and more attention. A gene encoding a thermophilic glycoside hydrolase from Fervidobaterium pennivorans DSM9078 was cloned and expressed in Escherichia coli. The purified recombinant enzyme, exhibiting endoglucanase cellulase activity, was used to transform gypenoside XLIX into gylongiposide I via highly selective and efficient hydrolysis of the glucose moiety linked to the C21 position in gypenoside XLIX. Under the optimal reaction conditions for large scale production of gylongiposide I, 35 g gypenoside XLIX was transformed by using 20 g crude enzyme at pH 6.0 and 80 °C for 4 h with a molar yield of 100%. Finally, 11.51 g of gylongiposide I was purified using a silica gel column with 91.84% chromatographic purity. Furthermore, inhibitory activities of gypenoside XLIX and gylongiposide I against Enterovirus 71 (EV71) were investigated. Importantly, the EC50 of gypenoside XLIX and gylongiposide I calculated from viral titers in supernatants was 3.53 µM and 1.53 µM, respectively. Moreover, the transformed product gylongiposide I has better anti-EV71 activity than the glycosylated precursor. In conclusion, this enzymatic method would be useful in the large-scale production of gylongiposide I, which would be a novel potent anti-EV71 candidate.

Mechanisms of Gynostemma pentaphyllum against non-alcoholic fibre liver disease based on network pharmacology and molecular docking.

As a progressive chronic disease, the effective treatment for non-alcoholic fibre liver disease (NAFLD) has not yet been thoroughly explored at the moment. The widespread use of Gynostemma pentaphyllum (Thunb) for its anti-insulin resistance effect indicates that potential therapeutic value may be found in Thunb for NAFLD. Hence, this research aims to discover the latent mechanism of Thunb for NAFLD treatment. To achieve the goal of discovering the latent mechanism of Thunb for NAFLD treatment, molecular docking strategy integrated a network phamacology was adopted in the exploration. We acquire Thunb compounds with activeness from TCMSP database. We collect the putative targets of Thunb and NAFLD to generate the network. Key targets and mechanism are screened by PPI analysis, GO and KEGG pathway enrichment analyses. Molecular docking simulation is introduced into the study as assessment method. Through network analysis and virtual screening based on molecular docking, 2 targets (AKT 1 and GSK3B) are identified as key therapeutic targets with satisfying binding affinity. Main mechanism is believed to be the biological process and pathway related to insulin resistance according to the enrichment analyses outcomes. Particularly, the P13K-AKT signalling pathway is recognized as a key pathway of the mechanism. In conclusion, the study shows that Thunb could be a potential treatment against NAFLD and may suppress insulin resistance through the P13K-AKT signalling pathway. The result of the exploration provides a novel perspective for approaching experimental exploration.

GP-14 protects against severe hypoxia-induced neuronal injury through the AKT and ERK pathways and its induced transcriptome profiling alteration.

Gypenosides are major bioactive ingredients of G. pentaphyllum. In our previous study, we found that gypenosides had neuroprotective effects against hypoxia-induced injury. In the current study, we focused on the protective effects of gypenoside-14 (GP-14), which is one of the newly identified bioactive components, on neuronal injury caused by severe hypoxia (0.3% O2). The results showed that GP-14 pretreatment alleviated the cell viability damage and apoptosis induced by hypoxia in PC12 cells. Moreover, GP-14 pretreatment also attenuated primary neuron injuries under hypoxic conditions. Additionally, GP-14 pretreatment significantly ameliorated neuronal damage in the hippocampal region induced by high-altitude cerebral edema (HACE). At the molecular level, GP-14 pretreatment reversed the decreased activities of the AKT and ERK signaling pathways caused by hypoxia in PC12 cells and primary neurons. To comprehensively explore the possible mechanisms, transcriptome sequencing was conducted, and these results indicated that GP-14 could alter the transcriptional profiles of primary neuron. Taken together, our results suggest that GP-14 acts as a neuroprotective agent to protect against neuronal damage induced by severe hypoxia and it is a promising compound for the development of neuroprotective drugs.

Beneficial effects of Gynostemma pentaphyllum honey paste on obesity via counteracting oxidative stress and inflammation: An exploration of functional food developed from two independent foods rich in saponins and phenolics.

The development of functional foods that possess a combination of biological functions and good sensory properties is an emerging topic in the field of food and function. Gynostemma pentaphyllum (G. pentaphyllum) is widely considered to exert anti-obesity effect owing to its abundant saponins and other bioactive components, but bitter and unacceptable taste limit its utilization. While honey, a natural sweetener, not only has the pleasure sense but is also usually used as the carrier of functional food due to its phenolic oligosaccharide, etc. In the present study, we proposed the preparation method of a G. pentaphyllum honey paste (GH) and its beneficial effects on obese mice. The results showed that GH contented 0.055 mg/g Gypenoside XLIX, 0.01 mg/g Gypenoside A, and 11 kinds of phenolics. It could down-regulate 23.3% of liver TC level, increase serum ALT activity, improve liver tissue damage and epididymal adipocyte hypertrophy than obese mice. Besides, GH regulated enzyme activities such as SOD and GSH to enhance oxidative stress defense and exerted anti-inflammatory activity via IL-6 (52.4%), TNF-α (38.7%), IFN-γ (32%) and NF-κB (28%) genes down-regulation, which also reshaped the gut microbiota structure, exerting anti-obesity effects. More importantly, GH promoted obese mice appetite with orexin-A compared to G. pentaphyllum alone. This study provided a new perspective on the development of G. pentaphyllum functional foods with both good organoleptic performance and obesity therapy.