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.

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.

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.

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.

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.

[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.

New dammarane-type triterpenoid saponins from Gynostemma pentaphyllum and their Sirt1 agonist activity.

Gynostemma pentaphyllum (Thunb.) Makino (Cucurbitaceae family) is a perennial creeping plant with a common Chinese name of "south ginseng". To date, more than 250 individual saponins with dammarane-type skeleton have been isolated from G. pentaphyllum. The purpose of this study was the isolation and structural characterization of novel, minor gypenosides from G. pentaphyllum and evaluation of their Sirt1 agonist activity. Individual saponins from G. pentaphyllum were isolated and purified by a variety of chromatography techniques, and their structures were elucidated by means of various spectroscopic analysis and comparision with the reported data. Sirt1 enzyme activity detection kit was used to preliminarily evaluate the Sirt1 agonist activity of thirty three individual saponins purified from G. pentaphyllum. Fourteen new triterpenoid saponins named gypenoside CII-CXV (1-14) along with twenty six known compounds (15-40) were isolated from G. pentaphyllum. Thirty three of all the isolates were screened for Sirt1 agonist activity, and the results showed that three dammarane-type saponins (2, 18, 37) and one cucurbitane-type saponin 33 exhibited satisfactory Sirt1 agonist activity. These findings suggested that G. pentaphyllum was worthy of further investigation to find small molecule Sirt1 agonist and facilitate their utilization as "south ginseng".

New dammarane-type glycosides from Gynostemma pentaphyllum and their lipid-lowering activity.

Gynostemma pentaphyllum (Thunb.) Makino has a long history as food and diary supplement in China. At present, there are some products for hyperlipidemia in the market, including G. pentaphyllum tea, healthy wine and healthy food. In order to discover proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, fourteen new triterpenoid saponins named gypenoside LXXXVIII-CI (1-14) along with six known compounds (15-20) were isolated from G. pentaphyllum. Their structures were elucidated by means of various spectroscopic techniques. Eight isolates were evaluated the inhibitory effect on PCSK9 in HepG2 cells. The results showed that three dammarane-type glycosides (2, 3, 15) remarkably reduced PCSK9 expression at 10 µM concentration. These findings suggested that G. pentaphyllum was worthy of further investigation to find small molecule PCSK9 inhibitors and facilitate their utilization as functional food ingredients.

Protective effects of four new saponins from Gynostemma pentaphyllum against hydrogen peroxide-induced neurotoxicity in SH-SY5Y cells.

Gynostemma pentaphyllum has been used as a medicine-food homologious health product in China for a long time. This research aimed to isolate and identify its active compounds with protective effects against hydrogen peroxide induced SH-SY5Y cell death. Four new dammarane-type saponins were isolated from G. pentaphyllum using various chromatographic methods. They were identified as gypenoside S1 (1), gypenoside S3 (2), gypenoside S2 (3) and gypenoside S4 (4), respectively by HRESIMS and NMR spectra. Their cytotoxic activity was evaluated against three human cancer cell lines, A549 (lung), HepG2 (liver), SH-SY5Y (nerve), by MTT method. They showed low cytotoxicities with the IC50 values of more than 100 µM on three cancer cell lines. However, they appeared protective effects against hydrogen peroxide induced SH-SY5Y cell death in a dose-dependent manner. They recovered cell viability more than 69% at the concentration of 20 µM from 66%, while as vitamin C to 67%. Compound 3 and 4 recovered more than 79% at 100 µM. The present study suggests that G. pentaphyllum has antioxidative potential and the saponins from G. pentaphyllum are considered as the active compounds with safe and neuroprotecitve effect.

Protective Effects of Gynostemma pentaphyllum (var. Ginpent) against Lipopolysaccharide-Induced Inflammation and Motor Alteration in Mice.

Gynostemma pentaphyllum (var. Ginpent) (GP) is a variety of Cucurbit with anti-inflammatory and antioxidant effects in patients. In this manuscript, the main components present in the dry extract of GP have been identified using Ultra High Performance Liquid Chromatography quadrupole-time-of-flight mass spectrometry (UHPLC/Q-TOF-MS). In addition, the anti-inflammatory action of GP was evaluated in animal models with acute peripheral inflammation and motor alteration induced by lipopolysaccharide. The results showed that GP dry extract is rich in secondary metabolites with potential antioxidant and anti-inflammatory properties. We found that the treatment with GP induced a recovery of motor function measured with the rotarod test and pole test, and a reduction in inflammatory cytokines such as interleukin-1ß and interleukin-6 measured with the ELISA test. The data collected in this study on the effects of GP in in vivo models may help integrate the therapeutic strategies of inflammatory-based disorders.

Progress in the Medicinal Value, Bioactive Compounds, and Pharmacological Activities of Gynostemma pentaphyllum.

Gynostemma pentaphyllum (Thunb.) Makino (GP), also named Jiaogulan in Chinese, was known to people for its function in both health care and disease treatment. Initially and traditionally, GP was a kind of tea consumed by people for its pleasant taste and weight loss efficacy. With the passing of the centuries, GP became well known as more than just a tea. Until now, numbers of bioactive compounds, including saponins (also named gypenosides, GPS), polysaccharides (GPP), flavonoids, and phytosterols were isolated and identified in GP, which implied the great medicinal worth of this unusual tea. Both in vivo and in vitro tests, ranging from different cell lines to animals, indicated that GP possessed various biological activities including anti-cancer, anti-atherogenic, anti-dementia, and anti-Parkinson's diseases, and it also had lipid-regulating effects as well as neuroprotection, hepatoprotective, and hypoglycemic properties. With the further development and utilization of GP, the research on the chemical constituents and pharmacological properties of GP were deepening day by day and had made great progress. In this review, the recent research progress in the bioactive compounds, especially gypenosides, and the pharmacological activities of GP were summarized, which will be quite useful for practical applications of GP in the treatment of human diseases.

Activity Components from Gynostemma pentaphyllum for Preventing Hepatic Fibrosis and of Its Molecular Targets by Network Pharmacology Approach.

Hepatic fibrosis would develop into cirrhosis or cancer without treating. Hence, it is necessary to study the mechanism and prevention methods for hepatic fibrosis. Gynostemma pentaphyllum is a traditional medicinal material with a high medicinal and health value. In this study, nineteen compounds obtained from G. pentaphyllum were qualitative and quantitative by HPLC-FT-ICR MS and HPLC-UV, respectively. Among them, the total content of 19 gypenosides accurately quantified reaches 72.21 mg/g and their anti-proliferation against t-HSC/Cl-6 cells indicated compound 19 performed better activity (IC50: 28.1 ± 2.0 µM) than the other compounds. Further network pharmacology study demonstrated that compound 19 mainly plays an anti-fibrosis role by regulating the EGFR signaling pathway, and the PI3K-Akt signaling pathway. Overall, the verification result indicated that compound 19 appeared to be nontoxic to LO2, was able to modulate the PI3K/Akt signal, led to subG1 cells cycle arrest and the activation of mitochondrial-mediated apoptosis of t-HSC/Cl-6 cells for anti-hepatic fibrosis.

Gypenosides mediate cholesterol efflux and suppress oxidized LDL induced inflammation in retinal pigment epithelium cells.

Age-related macular degeneration (AMD) is a predominant cause of visual deficit in aged population. Abnormal accumulation of cholesterol, including oxidized low-density lipoprotein (oxLDL), underneath the retinal pigment epithelium (RPE) cells contributes to the development of AMD. Gypenosides (Gyp) are glycosides extracted from Gynostemma pentaphyllum and have demonstrated protective effects against inflammation and oxidative stress. To determine the therapeutic potential of Gyp for AMD, we investigated its effect on cholesterol trafficking and metabolism and assessed the protective function of Gyp against oxLDL-induced damage in RPE cells. Cholesterol efflux to high-density lipoprotein (HDL) and human serum was significantly increased in RPE cells treated with Gyp when compared to untreated control cells. Expression of cholesterol metabolism (CYP27A1, CYP46A1) and trafficking (TSPO, ABCA1 and ABCG1) genes was also markedly increased in Gyp-treated RPE cells. OxLDL-treated RPE cells had significantly increased cholesterol accumulation and lipid droplet formation. There were marked increases in reactive oxygen species (ROS) generation and proinflammatory cytokines via NF-κB activation in RPE cells treated with oxLDL, while incubation with Gyp rectified these changes. These findings provide pharmacological evidence that Gyp has the potential to treat patients with early onset AMD by promoting cellular cholesterol removal from RPE cells and inhibiting inflammation and oxidative stress.

Effects of extraction methods on antioxidant and immunomodulatory activities of polysaccharides from superfine powder Gynostemma pentaphyllum Makino.

BACKGROUP: Superfine grinding (SG) technology has attracted considerable attention in food and medicine researcher fields. METHODS: Polysaccharides in superfine powder of Gynostemma pentaphyllum Makino (GPP) were extracted using three methods, including hot water extraction (HWE), ultrasound-assisted hot extraction (UAE), and microwave-assisted hot extraction (MAE), and the purified polysaccharides were specially denoted as GPWP, GPUP, and GPMP, respectively. The possible structures of polysaccharides were investigated by FT-IR, HPLC and SEM. In addition, the antioxidative and immunomodulatory activities were evaluated by in vitro radical-scavenging activity assay and immune cell functional evaluation. RESULTS: We observed that the yield of GPUP (20.31%) was relatively higher than that of GPWP (15.34%) and GPMP (16.96%). Among all products, GPWP exhibited the highest antioxidative activities against DPPH, hydroxyl, and superoxide anion radicals. GPWP could also preferably chelate Fe2+ and protect against the oxidative damage by increasing the cellular levels of antioxidant enzymes (SOD, CAT and GSH-PX) and decreasing the content of oxidation product (MDA). Three polysaccharides presented some extent of immunoregulatory activity by promoting the phagocytosis of mononuclear macrophages and elevating the levels of NO, TNF-ɑ, and IL-6, and among which GPWP showed the best. CONCLUSION: These results indicate that the HWE method is an excellent technique for extracting GPP with high bioactivities that would be suitable for various industrial applications. Graphical Abstract.

Monomer gypenoside LI from Gynostemma pentaphyllum inhibits cell proliferation and upregulates expression of miR-128-3p in melanoma cells.

Gypenosides have anticancer activity against many cancers. Gypenoside LI is a gypenoside monomer from Gynostemma pentaphyllum, its pharmacological functions in melanoma have not been reported. In this study, we found that gypenoside LI had a potent cytotoxic effect on melanoma cells. Gypenoside LI can induce intrinsic apoptosis along with S phase arrest. Furthermore, gypenoside LI inhibited the colony formation ability of melanoma through inhibition of the Wnt/ß-catenin signaling pathway. Interestingly, we also found that gypenoside LI can induce the upregulation of the tumor suppressor miR-128-3p during melanoma apoptosis. In contrast, gypenoside LI induced apoptosis, cell cycle arrest, and inhibition of the Wnt/ß-catenin signaling pathway, which were abolished by overexpression of the miR-128-3p inhibitor in A375 cells. Taken together, these results showed that gypenoside LI could inhibit human melanoma cells through inducing apoptosis, arresting cell cycle at the S phase and suppressing the Wnt/ß-catenin signaling pathway in a miR-128-3p dependent manner.

Ten New Dammarane-Type Saponins with Hypolipidemia Activity from a Functional Herbal Tea-Gynostemma pentaphyllum.

Gynostemma pentaphyllum (thumb.) Makino is a functional herbal tea commonly used in Asian countries and regions to reduce blood lipid levels. G. pentaphyllum saponin is the main component, but there are still a large number of components with lipid-lowering activity that have not been found. In this study, 10 novel dammarane-type saponins, (1-10) and a known one (11) were isolated from G. pentaphyllum. Ten new compounds were identified and named as yunnangypenosides A-J (1-10), and another known one (11) was also obtained. Their chemical structures were determined by MS, NMR spectroscopic analyses. Moreover, the cytotoxicities on human HepG-2 hepatocellular carcinoma cells of these isolates were evaluated, and the results showed that compounds 1-11 had no obvious cytotoxicity. Finally, all these compounds were evaluated for their lipid-lowering effect by means of the oil red O staining method. Ten compounds could significantly reduce lipid levels except of 2, especially 8 exhibite the strongest hypolipidemia activity.

Mushroom polysaccharides and jiaogulan saponins exert cancer preventive effects by shaping the gut microbiota and microenvironment in ApcMin/+ mice.

The incidence of colorectal cancer (CRC) is alarming among younger peoples. While no effective chemopreventive drug available in the market, researchers have been searching for alternative strategies against CRC that are in demand. Therefore, we tested the cancer-preventive properties of Ganoderma lucidum (Lingzhi) polysaccharides (GLP), along with the saponins extracted from Gynostemma pentaphyllum (GpS), an herbal tea with prebiotic-like effects. Here, we report that saponins from Gynostemma pentaphyllum (GpS) and polysaccharides from Ganoderma lucidum (GLP together with GpS) profoundly improved the inflamed gut barrier of ApcMin/+ mice by reducing polyps, shifting colonic M1 to M2 macrophages, positively reverting E-cadherin/N-cadherin ratio, and downregulating oncogenic signaling molecules. The treatments also markedly promoted short-chain fatty acids (SCFAs)-producing bacteria and abridged sulfate-reducing bacteria in a time-dependent manner. G-protein coupled-receptors were significantly stimulated in the treated mice, accompanied by the modulated expressions of histone deacetylases, anti-cancer gut hormone PYY, and PPAPγ. These findings suggest that some of the herbal medicinal foods could modulate the relationship between the host and the gut microbiota (GM) to exert their beneficial properties to the host. Our study also implicates that these dietary mushroom polysaccharides and the Gp saponins have the potential to be developed as new preventive medicines against CRC.

Assessment of the hepatocyte protective effects of gypenoside and its phosphorylated derivative against DHAV-1 infection on duck embryonic hepatocytes.

BACKGROUND: Duck viral hepatitis (DVH) is an acute disease of young ducklings with no effective veterinary drugs for treatment. Gynostemma pentaphyllum is a well-known traditional Chinese medicine that plays an important role in the treatment of various diseases. Gypenoside (GP), one of the main ingredients of Gynostemma pentaphyllum, was reported with good hepatoprotective effects. However, its low solubility limits its application in the clinics. To improve its solubility and bioactivity, a phosphorylated derivative of gypenoside (pGP) was prepared by the sodium trimetaphosphate-sodium tripolyphosphate (STMP-STPP) method. An infrared spectroscopy method was applied to analyse the structures of GP and pGP. Then, a methyl thiazolyl tetrazolium (MTT) colorimetric assay was applied to study the hepatocyte protective efficacy of these two drugs against duck hepatitis A virus type 1 (DHAV-1) infection, and qPCR, TUNEL labelling and flow cytometry methods were used to study the relevant hepatocyte protective in vitro. RESULTS: The infrared spectroscopy detection results showed that the phosphorylation modification of GP was successful. The MTT colorimetric assay results showed that both GP and pGP possessed good hepatocyte protective efficacy in vitro, and pGP performed better than GP when the drug was added before or after virus inoculation. Furthermore, the qPCR results revealed that both drugs could effectively inhibit the adsorption (when adding GP and pGP pre-virus inoculation), replication and release of DHAV-1, and the viral inhibition rate of pGP was greater than that of GP. The subsequent TUNEL labelling and flow cytometry assays showed that both GP and pGP could significantly inhibit duck embryo hepatocyte apoptosis induced by DHAV-1, and the inhibition effect of pGP was much stronger than that of GP. CONCLUSIONS: GP exerts good hepatocyte protective efficacy not only by inhibiting the proliferation of DHAV-1 but also by inhibiting duck embryonic hepatocyte apoptosis induced by DHAV-1, and phosphorylation modification significantly improves the antiviral and the anti-apoptotic effects of GP. Therefore, pGP has the potential to be developed into a novel drug against DHAV-1 infection.

Inhibitory Effect of Damulin B from Gynostemma pentaphyllum on Human Lung Cancer Cells.

Damulin B, a dammarane-type saponin from steamed Gynostemma pentaphyllum, exhibits the strongest activity against human lung carcinoma A549 cells among the isolated active saponins. In this study, the structure-activity relationship of a series of saponin compounds was discussed. The inhibitory effect of damulin B on human lung cancer A549 and H1299 cells was investigated from apoptosis, cell cycle, and migration aspects. In vitro, human lung cancer cells were more susceptible to damulin B treatment than human normal fibroblasts. Damulin B exhibited a strong cytotoxic effect, as evidenced by the increase of apoptosis rate, reduction of mitochondrial membrane potential (MMP), generation of reactive oxygen species, and G0/G1 phase arrest. Furthermore, damulin B activated the following: both intrinsic and extrinsic apoptosis pathways along with early G1 phase arrest via the upregulation of the Bax, Bid, tBid, cleaved caspase-8, and p53 expression levels; downregulation of the procaspase-8/-9, CDK4, CDK6, and cyclin D1 expression levels; and more release of cytochrome c in the cytoplasm. In addition, antimigratory activities and suppressive effects on metastasis-related factors, such as MMP-2 and MMP-9, accompanied by the upregulation of IL-24 were revealed. Altogether, the results proved that damulin B could inhibit human lung cancer cells by inducing apoptosis, blocking the cell cycle at early G0/G1 phase and suppressing the migration. Hence, damulin B has potential therapeutic efficacy against lung cancer.