Selective induction of apoptosis in glioma tumour cells by a Gynostemma pentaphyllum extract

Gypenoside XLIX alleviates acute liver injury: Emphasis on NF-κB/PPAR-α/NLRP3 pathways

Liver is one of the vital organs in the human body and liver injury will have a very serious impact on human damage. Gypenoside XLIX is a PPAR-α activator that inhibits the activation of the NF-κB signaling pathway. The components of XLIX have pharmacological effects such as cardiovascular protection, antihypoxia, anti-tumor and anti-aging. In this study, we used cecum ligation and puncture (CLP) was used to induce in vivo mice hepatic injury, and lipopolysaccharide (LPS)-induced inflammation in RAW264.7 cells, evaluated whether Gypenoside XLIX could have a palliative effect on sepsis-induced acute liver injury via NF-κB/PPAR-α/NLRP3. In order to gain insight into these mechanisms, six groups were created in vivo: the Contol group, the Sham group, the CLP group, the CLP + XLIX group (40 mg/kg) and the Sham + XLIX (40 mg/kg) group, and the CLP + DEX (2 mg/kg) group. Three groups were created in vitro: Control, LPS, LPS + XLIX (40 μM). The analytical methods used included H&E staining, qPCR, reactive oxygen species (ROS), oil red O staining, and Western Blot. The results showed that XLIX attenuated hepatic inflammatory injury in mice with toxic liver disease through inhibition of the TLR4-mediated NF-κB pathway, attenuated lipid accumulation through activation of PPAR-α, and attenuated hepatic pyroptosis by inhibiting NLRP3 production. Regarding the imbalance between oxidative and antioxidant defenses due to septic liver injury, XLIX reduced liver oxidative stress-related biomarkers (ALT, AST), reduced ROS accumulation, decreased the amount of malondialdehyde (MDA) produced by lipid peroxidation, and increased the levels of antioxidant enzymes such as glutathione (GSH) and catalase (CAT). Our results demonstrate that XLIX can indeed attenuate septic liver injury. This is extremely important for future studies on XLIX and sepsis, and provides a potential pathway for the treatment of acute liver injury.

Angelica sinensis extract induces telomere dysfunction, cell cycle arrest, and mitochondria-mediated apoptosis in human glioblastoma cells

Glioblastoma (GB) is one of the most aggressive and malignant tumors of the central nervous system. Conventional treatment for GB requires surgical resection followed by radiotherapy combined with temozolomide chemotherapy; however, the median survival time is only 12-15 months. Angelica sinensis Radix (AS) is commonly used as a traditional medicinal herb or a food/dietary supplement in Asia, Europe, and North America. This study aimed to investigate the effect of AS-acetone extract (AS-A) on the progression of GB and the potential mechanisms underlying its effects. The results indicated that AS-A used in this study showed potency in growth inhibition of GB cells and reduction of telomerase activity. In addition, AS-A blocked the cell cycle at the G₀/G₁ phase by regulating the expression of p53 and p16. Furthermore, apoptotic morphology, such as chromatin condensation, DNA fragmentation, and apoptotic bodies, was observed in AS-A-treated cells, induced by the activation of the mitochondria-mediated pathway. In an animal study, AS-A reduced tumor volume and prolonged lifespans of mice, with no significant changes in body weight or obvious organ toxicity. This study confirmed the anticancer effects of AS-A by inhibiting cell proliferation, reducing telomerase activity, altering cell cycle progression, and inducing apoptosis. These findings suggest that AS-A has great potential for development as a novel agent or dietary supplement against GB.

Gypenoside-Induced Apoptosis via the PI3K/AKT/mTOR Signaling Pathway in Bladder Cancer

Gynostemma pentaphyllum (Thunb.) Makino (G. pentaphyllum) is a natural herbal drug that has been widely used to treat many diseases. The antitumor effects of G. pentaphyllum were first described in the illustrated catalog of plants. Gypenosides are the major active components of G. pentaphyllum, and they have been widely reported to possess antitumor effects in prostate cancer, gastric cancer, hepatocellular carcinoma, colon cancer, lung cancer, and breast cancer. However, research on the use of gypenoside in the treatment of bladder cancer has not been conducted. In this study, we explored the potential molecular mechanisms of gypenosides in the treatment of bladder cancer using network pharmacology and experimental validation. First, we used a network pharmacology-based method to identify both the effective components of gypenosides and the molecular mechanism underlying their antibladder cancer effects. The results were further confirmed by molecular docking, CCK8 and colony formation assays, and cell cycle and cell apoptosis analyses. Additionally, a mouse xenograft model of bladder cancer was used to investigate the antitumor effect of gypenosides in vivo. We identified 10 bioactive ingredients and 163 gene targets of gypenosides. Network exploration suggested that VEGFA, STAT3, and PI3KCA may be candidate agents for the antibladder cancer effect of gypenosides. In addition, analysis of the Kyoto Encyclopedia of Genes and Genomes pathway revealed that the phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway may play a crucial role in the mechanism of action of gypenosides against bladder cancer. Molecular docking revealed that gypenosides combine well with PI3K, AKT, and mTOR. As expected, gypenosides displayed apoptosis-inducing properties in bladder cancer cells by inactivating the PI3K/AKT/mTOR signaling pathway in vitro. Furthermore, gypenosides significantly (P < 0.05) inhibited the growth of bladder cancer cells in vivo. Mechanistically, gypenosides induced the apoptosis of bladder cancer cells via inactivation of the PI3K/AKT/mTOR signaling pathway.

Analysis of Serum Biochemical Indexes, Egg Quality, and Liver Transcriptome in Laying Hens Fed Diets Supplemented with Gynostemma pentaphyllum Powder

Gynostemma pentaphyllum (GP), known as “southern ginseng”, can reduce the blood pressure and blood lipid levels. In this study, 300 layer chicks of one day old were divided randomly into three groups (control group (base diet), high addition group (base diet with 1% GP), and low addition group (base diet with 0.5% GP)). After 29 weeks, the growth performance, egg quality, and serum index were determined. Additionally, liver mRNA was identified using RNA-seq to investigate the molecular mechanisms. The results indicated that the serum total cholesterol and triglycerides decreased significantly in the GP addition group. The addition of GP increased the egg weight, Haugh unit and redness (a*) of the egg yolk color, and reduced the yolk cholesterol concentration. Moreover, 95 differentially expressed genes (DEGs) were screened between the control and GP addition group. GO and the KEGG analysis showed that the PPAR pathway was significantly enriched. Five fatty acid metabolism-related genes (FABP3, CYP7A1, ANKRD22, SCD1, and PCK1) were validated by qRT-PCR analysis, which confirmed the tendency of the expression. These DEGs in the PPAR pathway may be the key factors of GP affecting fatty acid metabolism. These results may provide a theoretical basis for further research and new insights into GP as a feed additive.

Therapeutic Potential of Berberine in the Treatment of Glioma: Insights into Its Regulatory Mechanisms

Glioma is known as one of the most common primary intracranial tumors accounting for four-fifths of malignant brain tumors. There are several biological pathways that play a synergistic, pathophysiological role in glioma, including apoptosis, autophagy, oxidative stress, and cell cycle arrest. According to previous rese arches, the drugs used in the treatment of glioma have been associated with significant limitations. Therefore, improved and/or new therapeutic platforms are required. In this regard, multiple flavonoids and alkaloids have been extensively studied in the treatment of glioma. Berberine is a protoberberine alkaloid with wide range of pharmacological activities, applicable to various pathological conditions. Few studies have reported beneficial roles of berberine in glioma. Berberine exerts its pharmacological functions in glioma by controlling different molecular and cellular pathways. We reviewed the existing knowledge supporting the use of berberine in the treatment of glioma and its effects on molecular and cellular mechanisms.

Pharmacological intervention in oxidative stress as a therapeutic target in neurological disorders

OBJECTIVES

Oxidative stress is a major cellular burden that triggers reactive oxygen species (ROS) and antioxidants that modulate signalling mechanisms. Byproducts generated from this process govern the brain pathology and functions in various neurological diseases. As oxidative stress remains the key therapeutic target in neurological disease, it is necessary to explore the multiple routes that can significantly repair the damage caused due to ROS and consequently, neurodegenerative disorders (NDDs). Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is the critical player of oxidative stress that can also be used as a therapeutic target to combat NDDs.

KEY FINDINGS

Several antioxidants signalling pathways are found to be associated with oxidative stress and show a protective effect against stressors by increasing the release of various cytoprotective enzymes and also exert anti-inflammatory response against this oxidative damage. These pathways along with antioxidants and reactive species can be the defined targets to eliminate or reduce the harmful effects of neurological diseases.

SUMMARY

Herein, we discussed the underlying mechanism and crucial role of antioxidants in therapeutics together with natural compounds as a pharmacological tool to combat the cellular deformities cascades caused due to oxidative stress.

Mechanism of gypenosides of Gynostemma pentaphyllum inducing apoptosis of renal cell carcinoma by PI3K/AKT/mTOR pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Gynostemma pentaphyllum (Thunb.) Makino is a traditional medicine commonly used in China, East Asia and Southeast Asia. In clinic, it is mainly used for hyperlipidemia and antitumor. Its antitumor activity was first recorded in "Illustrated Catalogue of Plants". Gypenosides were the main active ingredients of G. pentaphyllum. The anticancer activity of gypenosides in vivo and in vitro had been widely reported. However, the mechanism of gypenosides in renal cell carcinoma (RCC) still unclear.

AIM OF THE STUDY

In this study, we tried to investigate the active constituents from G. pentaphyllum and potential mechanisms in RCC treatment through network pharmacology and in vitro experiments.

MATERIAL/METHODS

Active compounds and their targets were evaluated and screened through TCMSP and Swiss Target Prediction database. Notably, nine preliminary screened components obtained from database were identified by LC-MS and LC-MS/MS. The targets associated with RCC were obtained from OMIM, TTD and GeneCards database. The PPI network and active component/target/pathway networks were constructed to identify the potential drug targets using String database and Cytoscape software. The functions and pathways of targets were analyzed through DAVID database. Finally, AutoDockTools 1.5.6 was used for molecular docking to assess the binding ability between compounds and targets. To support our prediction, we then explore the antitumor effect and mechanism of gypenosides by vitro experiments. CCK8 and flow cytometry were performed to evaluate cell death treated with gypenosides. Quantitative real-time PCR and Western blot were conducted to detect the changes of PI3K/AKT/mTOR signaling pathway.

RESULTS

Nine saponins and 68 targets have been screened. The hub targets covered PIK3CA, VEGFA, STAT3, JAK2, CCND1 and MAPK3. Enrichment analysis showed that the pathways mainly contained PI3K/Akt/mTOR, HIF-1, TNF, JAK-STAT and MAPK signaling pathways. Gypenosides extracted from G. pentaphyllum showed strong activity against 786-O and Caki-1 cells, and cell apoptosis were detected through Annexin V/PI dual staining assay. RT-qPCR showed that gypenosides downregulated the levels of PIK3CA, Akt and mTOR in Caki-1 and 786-O cells. Mechanistically, gypenosides induced apoptosis of RCC cells through regulating PI3K/Akt/mTOR signaling pathway which was implemented though decreasing the phosphorylation level of Akt and mTOR.

CONCLUSIONS

Gypenosides induced apoptosis of RCC cells by modulating PI3K/Akt/mTOR signaling pathway.

Triterpenoids from the genus Gynostemma: Chemistry and pharmacological activities

ETHNOPHARMACOLOGICAL RELEVANCE

G. pentaphyllum, also known as Jiao-Gu-Lan, has been used traditionally as folk remedies for many diseases, including diabetes mellitus, metabolic syndrome, aging, and neurodegenerative diseases in China and some countries in East and Southeast Asia. It is considered as an "immortality herb" in Guizhou Province, because it was consumed regularly by the elderly native inhabitants. Other species of the same genus Gynostemma such as G. longipes and G. laxum have been used as alternatives to G. pentaphyllum in ethno-medicine in Vietnam and other Asian countries.

AIM OF THE REVIEW

The review aims to summarize up-to-date study results on Gynostemma species, including traditional usage, phytochemical profile, pharmacological activities, and toxicological studies, in order to suggest future research orientation and therapeutic applications on acute and chronic diseases.

MATERIALS AND METHODS

The relevant literature on the genus Gynostemma was gathered from secondary databases (Web of Science and PubMed), books, and official websites. The latest literature cited in this review was published in February 2020.

RESULTS

The genus Gynostemma has been widely used in traditional medicine, mainly for treatment of diabetes, hypertension, obesity, and hepatosteatosis. To date, 328 dammarane-type saponins were isolated and structurally elucidated from Gynostemma species. Crude extracts, saponin-rich fractions (gypenosides), and pure compounds were reported to show a wide range of pharmacological activities in both in vitro and in vivo experiments. The most notable pharmacological effects were anti-cancer, cardioprotective, hepatoprotective, neuroprotective, anti-diabetic, anti-obesity, and anti-inflammatory activities. Toxicological studies were conducted only on G. pentaphyllum, showing that the plant extracts were relatively safe in both acute and long-term toxicity experiments at the given dosage while no toxicological studies were reported for the other species.

CONCLUSIONS

The review summarizes current studies on traditional uses, phytochemistry, biological properties, and toxicology of medicinal Gynostemma species. Till now, the majority of publications still focused only on G. pentaphyllum. However, the promising preliminary data of other Gynostemma species indicated the research potential of this genus, both in phytochemical and pharmacological aspects. Furthermore, clinical data are required to evaluate the efficacy and undesired effects of crude extracts, standard saponin fractions, and pure compounds prepared from Gynostemma medicinal plants.

Formulation and characterization of oil-in-water nanoemulsions stabilized by crude saponins isolated from onion skin waste

In the current work, a detailed study of crude saponins isolated from onion skin waste (OSW) was carried out to minimize the interfacial tension (γ) at oil-water interfaces, and to evaluate important factors on the formulation and characterization of nanoemulsions (NEs) stabilized by OSW saponins as a new natural emulsifier. It was found that OSW saponins are moderately strong surface-active agents. The droplet size of OSW saponin-stabilized NEs formulated by a high-pressure homogenizer was significantly dependent on processing parameters, where volume mean droplet diameter (d _4,3) decreased as homogenization pressure and emulsifier concentration increased. The d _4,3 of NEs formulated from soybean oil, sunflower oil, and medium-chain triglyceride (MCT) oil was <140 nm, which was much smaller than those prepared using orange oil (d _4,3 > 800 nm). The OSW saponin-coated droplets in soybean-based NEs showed stability against thermal treatment (30-90 °C, 30 min), pH (7-9), and ionic strength (NaCl < 50 mM). The NEs exhibited instability with droplet coalescence at relatively low pH (3-6), and high ionic strength (NaCl > 50 mM). The NEs stabilized by 0.5-1% (w/w) OSW were highly stable without an increase in d _4,3 during the storage (60 days) at 25 °C. Overall, these results suggest that OSW saponins are an efficient natural emulsifier, with significant potential to replace synthetic emulsifiers in certain practical applications.

Herbal Medicine for Cardiovascular Diseases: Efficacy, Mechanisms, and Safety

Cardiovascular diseases (CVDs) are a significant health burden with an ever-increasing prevalence. They remain the leading causes of morbidity and mortality worldwide. The use of medicinal herbs continues to be an alternative treatment approach for several diseases including CVDs. Currently, there is an unprecedented drive for the use of herbal preparations in modern medicinal systems. This drive is powered by several aspects, prime among which are their cost-effective therapeutic promise compared to standard modern therapies and the general belief that they are safe. Nonetheless, the claimed safety of herbal preparations yet remains to be properly tested. Consequently, public awareness should be raised regarding medicinal herbs safety, toxicity, potentially life-threatening adverse effects, and possible herb–drug interactions. Over the years, laboratory data have shown that medicinal herbs may have therapeutic value in CVDs as they can interfere with several CVD risk factors. Accordingly, there have been many attempts to move studies on medicinal herbs from the bench to the bedside, in order to effectively employ herbs in CVD treatments. In this review, we introduce CVDs and their risk factors. Then we overview the use of herbs for disease treatment in general and CVDs in particular. Further, data on the ethnopharmacological therapeutic potentials and medicinal properties against CVDs of four widely used plants, namely Ginseng, Ginkgo biloba, Ganoderma lucidum, and Gynostemma pentaphyllum, are gathered and reviewed. In particular, the employment of these four plants in the context of CVDs, such as myocardial infarction, hypertension, peripheral vascular diseases, coronary heart disease, cardiomyopathies, and dyslipidemias has been reviewed, analyzed, and critically discussed. We also endeavor to document the recent studies aimed to dissect the cellular and molecular cardio-protective mechanisms of the four plants, using recently reported in vitro and in vivo studies. Finally, we reviewed and reported the results of the recent clinical trials that have been conducted using these four medicinal herbs with special emphasis on their efficacy, safety, and toxicity.

Gynostemma Pentaphyllum Extract Ameliorates High-Fat Diet-Induced Obesity in C57BL/6N Mice by Upregulating SIRT1

Gynostemma pentaphyllum is widely used in Asia as a herbal medicine to treat type 2 diabetes, dyslipidemia, and inflammation. Here, we investigated the anti-obesity effect and underlying mechanism of G. pentaphyllum extract (GPE) enriched in gypenoside L, gypenoside LI, and ginsenoside Rg3 and obtained using a novel extraction method. Five-week-old male C57BL/6N mice were fed a control diet (CD), high-fat diet (HFD), HFD + 100 mg/kg body weight (BW)/day GPE (GPE 100), HFD + 300 mg/kg BW/day GPE (GPE 300), or HFD + 30 mg/kg BW/day Orlistat (Orlistat 30) for 8 weeks. The HFD-fed mice showed significant increases in body weight, fat mass, white adipose tissue, and adipocyte hypertrophy compared to the CD group; but GPE inhibited those increases. GPE reduced serum levels of triglyceride, total cholesterol, and LDL-cholesterol, without affecting HDL-cholesterol. GPE significantly increased AMPK activation and suppressed adipogenesis by decreasing the mRNA expression of CCAAT/enhancer binding protein-α (C/EBPα), peroxisome proliferator-activated receptor-γ (PPARγ), sterol regulatory element-binding protein-1c (SREBP1c), PPARγ coactivator-1α, fatty acid synthase (FAS), adipocyte protein 2 (AP2), and sirtuin 1 (SIRT1) and by increasing that of carnitine palmitoyltransferase (CPT1) and hormone- sensitive lipase (HSL). This study demonstrated the ameliorative effect of GPE on obesity and elucidated the underlying molecular mechanism.

Four new dammarane-type triterpenes derivatives from hydrolyzate of total Gynostemma pentaphyllum saponins and their bioactivities

Phytochemical investigation of hydrolysate of total G. pentaphyllum saponins led to the isolation of four novel triterpenes, Gypensapogenin U (1), Gypensapogenin V (2), Gypensapogenin W (3) and Gypensapogenin X (4). The structures of these compounds were identified by 1D, 2D-NMR and HR-ESI-MS evidences. Additionally, the protective activity of these new compounds against cardiomyocytes injury induced by H2O2 and their cytotoxic activity against t-HSC/Cl-6 cells were evaluated.

Gynostemma pentaphyllum is neuroprotective in a rat model of cardiopulmonary resuscitation

Asphyxial cardiac arrest (ACA)-induced ischemia results in acute and delayed neuronal cell death. The early reperfusion phase is critical for the outcome. Intervention strategies directed to this period are promising to reduce ACA/resuscitation-dependent impairments. This study focused on the evaluation of the protective potential of an extract from Gynostemma pentaphyllum (GP), a plant used in traditional medicine with antioxidative, glucose lowering and neuroprotective activities, in an ACA rat model. We tested the following parameters: i) Basic systemic parameters such as pCO₂ and blood glucose value within the first 30 min post-ACA; ii) mitochondrial response by determining activities of citrate synthase, respiratory chain complexes I + III and II + III, and the composition of cardiolipin 6 and 24 h post-ACA; iii) neuronal vitality of the CA1 hippocampal region by immunohistochemistry 24 h and 7 days post-ACA; and iv) cognitive function by a novel object recognition test 7 days post-ACA. GP, administered after reaching spontaneous circulation, counteracted the following: i) ACA-mediated increases in arterial CO₂ tension and blood glucose values; ii) transient increase in the activity of the respiratory chain complexes II + III; iii) elevation in cardiolipin content; iv) hippocampal CA1 neurodegeneration, and v) loss of normal novelty-object seeking. The protective effects of GP were accompanied by side effects of the vehicle DMSO, such as the stimulation of citrate synthase activity in control animals, inhibition of cardiolipin synthesis in ACA animals and complex II + III activity in both control and ACA animals. The results emphasize the importance of the early post-resuscitation phase for the neurological outcome after ACA/resuscitation, and demonstrated the power of GP substitution as neuroprotective intervention. Moreover, the results underline the need of a careful handling of the popular vehicle DMSO.

Targeting of growth factors in the treatment of hepatocellular carcinoma: The potentials of polysaccharides

Hepatocellular carcinoma (HCC) has become a leading cause of cancer-associated mortality worldwide and is thus of great concern. Although various chemotherapeutic drugs are currently used for the treatment of HCC, severe side effects associated with these treatments have prompted interest in novel therapies, including the use of certain biological macromolecules such as polysaccharides. Several studies have shown that polysaccharides have anticancer and antiproliferative effects on HCC. Vascular endothelial growth factor, transforming growth factor β, epidermal growth factor and fibroblast growth factor may be effective targets for polysaccharides and may modulate tumor growth and immunity through increasing the expression levels of cytokines. The present review focuses on the ways in which growth factors contribute to the development of HCC, and on the anti-growth factor activities of natural and synthetic polysaccharides, as well as their effect on proinflammatory cytokines.

Anti-cancer effects of Gynostemma pentaphyllum (Thunb.) Makino (Jiaogulan)

Gynostemma pentaphyllum (Thunb.) Makino (GpM) (Jiaogulan) has been widely used in Chinese medicine for the treatment of several diseases, including hepatitis, diabetes and cardiovascular disease. Furthermore, GpM has recently been shown to exhibit potent anti-cancer activities. In this review, we have summarized recent research progress on the anti-cancer activities and mechanisms of action of GpM, as well as determining the material basis for the anti-cancer effects of GpM by searching the PubMed, Web of Science and China National Knowledge Infrastructure databases. The content of this review is based on studies reported in the literature pertaining to the chemical components or anti-cancer effects of GpM up until the beginning of August, 2016. This search of the literature revealed that more than 230 compounds have been isolated from GpM, and that most of these compounds (189) were saponins, which are also known as gypenosides. All of the remaining compounds were classified as sterols, flavonoids or polysaccharides. Various extracts and fractions of GpM, as well as numerous pure compounds isolated from this herb exhibited inhibitory activity towards the proliferation of cancer cells in vitro and in vivo. Furthermore, the results of several clinical studies have shown that GpM formula could have potential curative effects on cancer. Multiple mechanisms of action have been proposed regarding the anti-cancer activities of GpM, including cell cycle arrest, apoptosis, inhibition of invasion and metastasis, inhibition of glycolysis and immunomodulating activities.

Gypenosides induce apoptosis by ca2+ overload mediated by endoplasmic-reticulum and store-operated ca2+ channels in human hepatoma cells

Gypenosides (Gyps) are triterpenoid saponins contained in an extract from Gynostemma pentaphyllum Makino and reported to induce apoptosis in human hepatoma cells through Ca(2+)-implicated endoplasmic reticulum (ER) stress and mitochondria-dependent pathways. The mechanism underlying the Gyp-increased intracellular Ca(2+) concentration ([Ca(2+)]i) is unclear. Here, we examined Gyp-induced necrosis and apoptosis in human hepatoma HepG2 cells. Gyp-induced apoptotic cell death was accompanied by a sustained increase in [Ca(2+)]i level. Gyp-increased [Ca(2+)]i level was partly inhibited by removal of extracellular Ca(2+) by Ca(2+) chelator EGTA, store-operated Ca(2+) channel (SOC) inhibitor 2- aminoethoxydiphenyl borate (2-APB), and ER Ca(2+)-release-antagonist 3,4,5-trimethoxybenzoic acid 8-(diethylamino) octyl ester (TMB-8). The strongest inhibitory effect was observed with TMB-8. EGTA, 2-APB, and TMB-8 also protected against Gyp-induced apoptosis in HepG2 cells. The combination of 2-APB and TMB-8 almost completely abolished the Gyp-induced Ca(2+) response and apoptosis. In contrast, the sarco/endoplasmic-reticulum-Ca(2+)-ATPase (SERCA) inhibitor thapsigargin slightly elevated Gyp-induced [Ca(2+)]i increase and apoptosis in HepG2 cells. Exposure to 300 μg/mL Gyp for 24 hours upregulated protein levels of inositol 1,4,5-trisphosphate receptor and SOC and downregulated that of SERCA for at least 72 hours. Thus, Gyp-induced increase in [Ca(2+)]i level and consequent apoptosis in HepG2 cells may be mainly due to enhanced Ca(2+) release from ER stores and increased store-operated Ca(2+) entry.

Flavonoids from Gynostemma pentaphyllum exhibit differential induction of cell cycle arrest in H460 and A549 cancer cells

Flavonoids, containing mainly kaempferol rhamnohexoside derivatives, were extracted from Gynostemma pentaphyllum (G. pentaphyllum) and their potential growth inhibition effects against H460 non-small cell lung cancer cells was explored and compared to that on A549 cells. The extracted flavonoids were found to exhibit antiproliferation effects against H460 cells (IC₅₀ = 50.2 μg/mL), although the IC₅₀ of H460 is 2.5-fold that of A549 cells (IC₅₀ = 19.8 μg/mL). Further investigation revealed that H460 cells are more susceptible to kaempferol than A549, whereas A549 cell growth is better inhibited by kaempferol rhamnohexoside derivatives as compared with H460. In addition, flavonoids from G. pentaphyllum induced cell cycle arrest at both S and G2/M phases with concurrent modulated expression of the cellular proteins cyclin A, B, p53 and p21 in A549 cells, but not H460. On the contrary, apoptosis and concomitant alteration in balance of BCL-2 and BAX expression as well as activation of caspase-3 were equally affected between both cells by flavonoid treatment. These observations strongly suggest the growth inhibition discrepancy between H460 and A549 following flavonoid treatment can be attributed to the lack of cell cycle arrest in H460 cells and the differences between H460 and A549 cells may serve as contrasting models for further mechanistic investigations.

Toxicity evaluation of standardized extract of Gynostemma pentaphyllum Makino

ETHNOPHARMACOLOGICAL RELEVANCE

To evaluate the safety of standardized extract of Gynostemma pentaphyllum in rats.

MATERIALS AND METHODS

The water extract of Gynostemma pentaphyllum was prepared and standardized, the dry powder yielded 6% gypenosides. In the acute oral toxicity test, the single oral dose of 5000 mg/kg of Gynostemma pentaphyllum extract was given to female Sprague-Dawley rats. In subchronic toxicity test, the oral dose of 1000 mg/kg/day of the extract was given to rats in treatment and satellite groups for 90 days. Satellite groups of both sexes were kept for additional 28 days after 90-day treatment. Control rats received distilled water.

RESULTS

Standardized extract of Gynostemma pentaphyllum did not cause death or any toxic signs in rats. The daily administration of the extract for 90 days did not produce lethal or harmful effects. Although certain hematological and blood chemistry values (i.e., neutrophil, monocyte, glucose, and serum alkaline phosphatase levels) were found to be statistically different from the control group, however; these values were within the ranges of normal rats.

CONCLUSION

Standardized extract of Gynostemma pentaphyllum did not produce mortality or any abnormality in rats.

Dammarane-type saponins from heat-processed Gynostemma pentaphyllum show fortified activity against A549 cells

An ethanol extract from heat-processed Gynostemma pentaphyllum showed more potent cytotoxic activity against human lung adenocarcinoma A549 cells than that of raw G. pentaphyllum. Four constituents were isolated from heat-processed G. pentaphyllum using resin HP-20, silica gel and reversed ODS column chromatography. They were identified by mass and NMR spectra as damulin A and damulin B, gypenoside L and gypenoside LI, respectively. To evaluate the efficacy of these four constituents, the MTT cytotoxicity assay was performed using A549 cells. Based on the structure of these four constituents, the results indicate that the hydroxyl group in C-2 and double bond in C20(21) and C20(22) positions are of importance in inhibition of A549 cell proliferation.

Preconditioning of brain slices against hypoxia induced injury by a Gynostemma pentaphyllum extract--stimulation of anti-oxidative enzyme expression

A short period of hypoxia/hypoglycaemia (oxygen and glucose deprivation, OGD) induced by perfusion with O(2)/glucose-free medium caused immediate loss and incomplete restoration of evoked field potentials in the CA1 region of transverse hippocampus slices. OGD-dependent decrease in evoked field potentials can be prevented by a proceeding short OGD event (preconditioning). We report about a study investigating the effect of an ethanolic Gynostemma pentaphyllum extract on evoked field potentials when administered before the OGD episode. Using this procedure, the extract completely protected the cells of the slices from functional injury. In an astroglia rich cell culture the ethanolic Gynostemma pentaphyllum extract caused within 48 h of cultivation increased protein and activity levels of the anti-oxidative enzymes manganese superoxide dismutase (Mn-SOD) and glutathione peroxidase (GPx). Consequently, the cellular H(2)O(2) concentration remained at a low level. These data suggest that the Gynostemma pentaphyllum-mediated increase in antioxidative enzyme activities may contribute to the protection of transverse hippocampus slices from OGD induced functional injury. Our results demonstrate that the prophylactic administration of the ethanolic extract from Gynostemma pentaphyllum has a high potential to protect from ischemia/reperfusion injury.

Prevention of free fatty acid-induced lipid accumulation, oxidative stress, and cell death in primary hepatocyte cultures by a Gynostemma pentaphyllum extract

Hepatocytes of a primary cell culture that are exposed to high glucose, insulin, and linoleic (LA) acid concentration respond with lipid accumulation, oxidative stress up to cell death. Such alterations are typically found in patients with non-alcoholic fatty liver disease (NAFLD). We used this cellular model to study the effect of an ethanolic Gynostemma pentaphyllum (GP) extract in NAFLD. When hepatocytes were cultured in the presence of high insulin, glucose, and LA concentration the extract completely protected the cells from cell death. In parallel, the extract prevented accumulation of triglycerides (TGs) and cholesterol as well as oxidative stress. Our data further demonstrate that GP stimulates the production of nitric oxide (NO) in hepatocytes and affects the molecular composition of the mitochondrial phospholipid cardiolipin (CL). We conclude that GP is able to protect hepatocytes from cell death, lipid accumulation, and oxidative stress caused by diabetic-like metabolism and lipotoxicity. Therefore, GP could be beneficial for patients with diabetes mellitus and NAFLD.

Antiproliferation effect and apoptosis mechanism of prostate cancer cell PC-3 by flavonoids and saponins prepared from Gynostemma pentaphyllum

The objectives of this study were to investigate the antiproliferation and apoptosis mechanism of saponin and flavonoid fractions from Gynostemma pentaphyllum (Thunb.) Makino on prostate cancer cell PC-3. Both flavonoid and saponin fractions were isolated by a column chromatographic method with Cosmosil 75C(18)-OPN as adsorbent and elution solvents of ethanol-water (30:70, v/v) for the former and 100% ethanol for the latter, followed by high-performance liquid chromatography-tandem mass spectrometry analysis. On the basis of the MTT assay, the saponin and flavonoid fraction were comparably effective in inhibiting the growth of PC-3 cells, with the IC(50) being 39.3 and 33.3 μg/mL, respectively. Additionally, both fractions induced an arrest of PC-3 cell cycle at both S and G2/M phases, with both early and late apoptotic cell populations showing a dose-dependent rise. The Western blot assay indicated that the incorporation of flavonoid or saponin fraction could modulate the expression of G2 and M checkpoint regulators, cyclins A and B, and the antiapoptotic proteins Bcl-2 and Bcl-xl and pro-apoptotic proteins Bad and Bax. The expression of the caspase-3 and its activated downstream substrate effectors, DFF45 and poly (ADP-ribose) polymerase-1 (PARP-1), was also increased and followed a dose-dependent manner. All of these findings suggest that the apoptosis of PC-3 cells may proceed through the intrinsic mitochondria pathway.

Chemical composition and anti-proliferative and anti-inflammatory effects of the leaf and whole-plant samples of diploid and tetraploid Gynostemma pentaphyllum (Thunb.) Makino

Leaf and whole-plant samples of the diploid and tetraploid Gynostemma pentaphyllum (GP) were investigated and compared for their chemical compositions, and their potential anti-proliferative and anti-inflammatory effects. The highest levels of total flavonoids and phenolics were observed in the diploid leaf botanical (2L3) at 36.84mg rutin equiv/g and 41.15mg gallic acid equiv/g, respectively. The diploid leaf sample (2L2) had the highest amount of rutin and quercetin contents of 77.7μmol quercetin equiv/g. The tetraploid whole-plant botanical (4L3) had the highest total saponin content of 227.1mg gypenoside equiv/g. Extracts from all tested GP samples showed time- and dose-dependent antiproliferative effects in HT-29 cells, and the diploid leaf samples had the overall highest inhibitory activity. These extracts had different order of antiproliferative properties in the LNCaP cells, suggesting the potential selective inhibition of GP extracts against different types of cancer cells and the effect of the cell model in screening and evaluation of antiproliferative components. In addition, the diploid leaf extracts showed the strongest inhibitory effects on the expression of TNF-α, IL-6 and COX-2 mRNA at final concentrations of 0.2 and 1mg botanical equiv/ml media. The results from this study will be used to develop new nutraceutical products from G. pentaphyllum.

Molecular evidence of anti-leukemia activity of gypenosides on human myeloid leukemia HL-60 cells in vitro and in vivo using a HL-60 cells murine xenograft model

We have shown that gypenosides (Gyp) induced cell cycle arrest and apoptosis in many human cancer cell lines. However, there are no reports showing that show Gyp acts on human leukemia HL-60 cells in vitro and in a murine xenograft model in vivo. In the present study effects of Gyp on cell morphological changes and viability, cell cycle arrest and induction of apoptosis in vitro and effects on Gyp in an in vivo murine xenograft model. Results indicated that Gyp induced morphological changes, decreased cell viability, induced G0/G1 arrest, DNA fragmentation and apoptosis (sub-G1 phase) in HL-60 cells. Gyp increased reactive oxygen species production and Ca(2+) levels but reduced mitochondrial membrane potential in a dose- and time-dependent manner. Gyp also changed one of the primary indicators of endoplasmic reticulum (ER) stress due to the promotion of ATF6-α and ATF4-α associated with Ca(2+) release. Gyp reduced the ratio of Bcl-2 to Bax due to an increase in the pro-apoptotic protein Bax and inhibited levels of the anti-apoptotic protein Bcl-2. Oral consumption of Gyp reduced tumor size of HL-60 cell xenograft mode mice in vivo. These results provide new information on understanding mechanisms by which Gyp induces cell cycle arrest and apoptosis in vitro and in vivo.

Translational research involving oxidative stress and diseases of aging

There is ample mounting evidence that reactive oxidant species are exacerbated in inflammatory processes, many pathological conditions, and underlying processes of chronic age-related diseases. Therefore there is increased expectation that therapeutics can be developed that act in some fashion to suppress reactive oxidant species and ameliorate the condition. This has turned out to be more difficult than at first expected. Developing therapeutics for indications in which reactive oxidant species are an important consideration presents some unique challenges. We discuss important questions including whether reactive oxidant species should be a therapeutic target, the need to recognize the fact that an antioxidant in a defined chemical system may be a poor antioxidant operationally in a biological system, and the importance of considering that reactive oxidant species may accompany the disease or pathological system rather than being a causative factor. We also discuss the value of having preclinical models to determine if the processes that are important in causing the disease under study are critically dependent on reactive oxidant species events and if the therapeutic under consideration quells these processes. In addition we discuss measures of success that must be met in commercial research and development and in preclinical and clinical trials and discuss as examples our translational research effort in developing nitrones for the treatment of acute ischemic stroke and as anti-cancer agents.

Preparative chromatography of flavonoids and saponins in Gynostemma pentaphyllum and their antiproliferation effect on hepatoma cell

A preparative column chromatographic method was developed to isolate flavonoids and saponins from Gynostemma pentaphyllum, a Chinese Medicinal herb, and evaluate their antiproliferation effect on hepatoma cell Hep3B, with the standards rutin and ginsenoside Rb(3) being used for comparison. Initially the powdered G. pentaphyllum was extracted with ethanol, followed by eluting flavonoids and saponins with ethanol-water (30:70, v/v) and 100% ethanol, respectively, in an open-column containing 5 g of Cosmosil 75C(18)-OPN, and then subjected to HPLC-MS analysis. The flavonoid fraction was mainly composed of quercetin- and kaempferol-glycosides, while in saponin fraction, both ginsenoside Rb(3) and ginsenoside Rd dominated. Both fractions were more effective against Hep3B cells than the standards rutin and ginsenoside Rb(3), with the cell cycle being arrested at G0/G1 phase for all the treatments. Additionally, the inhibition effect followed a dose-dependent increase for all the sample treatments. The result of this study may be used as a basis for possible phytopreparations in the future with G. pentaphyllum as raw material.