Protective effect of gypenosides against oxidative stress in phagocytes, vascular endothelial cells and liver microsomes

Effects of Gynostemma pentaphyllum on spinal cord motor neurons and microglial cells in vitro

The regenerative capability of spinal cord neurons is limited to impossible. Thus, experimental approaches supporting reconstruction/regeneration are in process. This study focused on the evaluation of the protective potency of an extract from Gynostemma pentaphyllum (GP), a plant used in traditional medicine with anti-oxidative and neuroprotective activities, in vitro on organotypic spinal cord cultures, the motor-neuron-like NSC-34 cell line and the microglial cell line BV-2. Organotypic cultures were mechanically stressed by the slicing procedure and the effect of GP on motor neuron survival and neurite sprouting was tested by immunohistochemistry. NSC-34 cells were neuronal differentiated by using special medium. Afterwards, cell survival (propidium iodide/fluorescein diacetate labeling), proliferation (BrdU-incorporation), and neurite sprouting were evaluated. BV-2 cells were stimulated with LPS/interferon γ and subjected to migration assay and nanoparticle uptake. Cell survival, proliferation and the expression pattern of different microglial activation markers (cFOS, iNOS) as well as transcription factors (PPARγ, YB1) were analyzed. In organotypic cultures, high-dose GP supported survival of motor neurons and especially of the neuronal fiber network. Despite reduced neurodegeneration, however, there was a GP-mediated activation of astro- and microglia. In NSC-34 cells, high-dosed GP had degenerative and anti-proliferative effects, but only in normal medium. Moreover, GP supported the neuro-differentiation ability. In BV-2 cells, high-dosed GP was toxic. In lower dosages, GP affected cell survival and proliferation when combined with LPS/interferon γ. Nanoparticle uptake, migration ability, and the transcription factor PPARγ, however, GP affected directly. The data suggest positive effects of GP on injured spinal motor neurons. Moreover, GP activated microglial cells. The dual role of microglia (protective/detrimental) in neurodegenerative processes required further experiments to enhance the knowledge about GP effects. Therefore, a possible clinical use of GP in spinal cord injuries is still a long way off.

Herbal Medicine for Slowing Aging and Aging-associated Conditions: Efficacy, Mechanisms and Safety

Aging and aging-associated diseases are issues with unsatisfactory answers in the medical field. Aging causes important physical changes which, even in the absence of the usual risk factors, render the cardiovascular system prone to some diseases. Although aging cannot be prevented, slowing down the rate of aging is entirely possible to achieve. In some traditional medicine, medicinal herbs such as Ginseng, Radix Astragali, Ganoderma lucidum, Ginkgo biloba, and Gynostemma pentaphyllum are recognized by the "nourishing of life" and their role as anti-aging phytotherapeutics is increasingly gaining attention. By mainly employing PubMed here we identify and critically analysed 30 years of published studies focusing on the above herbs' active components against aging and aging-associated conditions. Although many plant-based compounds appear to exert an anti-aging effect, the most effective resulted in being flavonoids, terpenoids, saponins, and polysaccharides, which include astragaloside, ginkgolide, ginsenoside, and gypenoside specifically covered in this review. Their effects as antiaging factors, improvers of cognitive impairments, and reducers of cardiovascular risks are described, as well as the molecular mechanisms underlying the above-mentioned effects along with their potential safety. Telomere and telomerase, PPAR-α, GLUTs, FOXO1, caspase-3, bcl-2, along with SIRT1/AMPK, PI3K/Akt, NF-κB, and insulin/insulin-like growth factor-1 pathways appear to be their preferential targets. Moreover, their ability to work as antioxidants and to improve the resistance to DNA damage is also discussed. Although our literature review indicates that these traditional herbal medicines are safe, tolerable, and free of toxic effects, additional well-designed, large-scale randomized control trials need to be performed to evaluate short- and long-term effects and efficacy of these medicinal herbs.

Gypenosides Protect Orbital Fibroblasts in Graves Ophthalmopathy via Anti-Inflammation and Anti-Fibrosis Effects

Purpose

To investigate the effect of Gypenosides (Gyps) on the inflammation and fibrosis in orbital fibroblasts (OFs) in Graves ophthalmopathy (GO).

Methods

Bioinformatics analyses were performed to identify the enriched genes and signaling pathways related to Gyps function. For ex vivo experiments, OFs were cultured from orbital connective tissues from patients with GO. OF proliferation was estimated by Cell Counting Kit-8 assay. Effects of Gyps treatment on interleukin (IL)-1β-induced inflammation and transforming growth factor-β1 (TGF-β1)-induced fibrosis were evaluated by real-time quantitative PCR (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), and Western blotting. OFs were treated with IL-1β or TGF-β1 in the absence or presence of Gyps pretreatment, and the levels of related mRNA or proteins were evaluated by RT-qPCR or ELISA.

Results

Eight inflammation-related target genes and nine fibrosis-related target genes were screened out. These genes were mainly enriched in pathways corresponding to inflammation and fibrosis, respectively. IL-1β-induced upregulation of inflammatory cytokines, and TGF-β-induced upregulation of fibrotic mediators in OFs were downregulated by Gyps. Moreover, Gyps reduced the activation of Toll like receptors 4/nuclear factor-κ B signaling and TGF-β1/SMAD2/SMAD4 signaling in GO OFs.

Conclusions

Gyps could protect GO-derived OFs against IL-1β-induced inflammation and TGF-β1-induced fibrosis. Thus Gyps might have therapeutic potential on inflammation and fibrosis in GO.

Medicinal Value and Potential Therapeutic Mechanisms of Gynostemma pentaphyllum (Thunb.) Makino and Its Derivatives: An Overview

:

Gynostemma pentaphyllum (Thunb.) Makino (GpM) and its derivatives, especially gypenosides (Gyps), are widely used as safe and convenient natural herbal drugs for the treatment of many diseases for a long time, and Gyps have different oral bioavailability (OB) values and low ability to cross the blood-brain barrier (BBB). The effects of GpM and isolates on fibrosis, inflammation, oxidation, proliferation and migration are proved. GpM shows bidirectional regulation effect on proliferation, oxidation and apoptosis in tumor and non-tumor cells. GpM and its extractions can resist proliferation, activate oxidation and apoptosis in tumor cells and have opposite effects on non-tumor cells. We succinctly present some current views of medicinal value and potential therapeutic mechanisms of GpM and its derivatives.

Gypenosides reverses depressive behavior via inhibiting hippocampal neuroinflammation

Gypenosides, a saponins extract isolated from the Gynostemma pentaphyllum plant, produces neuroprotective effects in the brain. Our previous studies have shown that hippocampal glucocorticoid receptor (GR)-brain-derived neurotrophic factor (BDNF)-TrkB signaling was involved in the antidepressant-like effects of gypenosides. It remains unknown whether gypenosides could alleviate neuroinflammation in depressive-like animals. The aim of the present study was to address this issue in chronic unpredictable mild stress (CUMS). Gypenosides was administrated for four weeks, followed by sucrose preference test and tail suspension test, which were performed to evaluate the effects of gypenosides. The results showed that gypenosides reversed both the decreased sucrose preference and increased immobility time in CUMS mice. In addition, gypenosides also attenuated the increase of pro-inflammatory cytokine levels in the hippocampus of CUMS animals. Furthermore, the activation of NF-κB, as well as its upstream mediators IKKα and IKKβ were inhibited by gypenosides. Last but not the least, CUMS promoted the activation of microglia, while gypenosides suppressed it according to the reduced number of iba1 positive cells. In conclusion, this study demonstrates that gypenosides exhibits the antidepressant-like effects in mice, which may be mediated by the inhibition of microglia and NF-κB signaling in the hippocampus.

Natural products as modulators of the nuclear receptors and metabolic sensors LXR, FXR and RXR

Nuclear receptors (NRs) represent attractive targets for the treatment of metabolic syndrome-related diseases. In addition, natural products are an interesting pool of potential ligands since they have been refined under evolutionary pressure to interact with proteins or other biological targets. This review aims to briefly summarize current basic knowledge regarding the liver X (LXR) and farnesoid X receptors (FXR) that form permissive heterodimers with retinoid X receptors (RXR). Natural product-based ligands for these receptors are summarized and the potential of LXR, FXR and RXR as targets in precision medicine is discussed.

Gynostemma pentaphyllum saponins attenuate inflammation in vitro and in vivo by inhibition of NF-κB and STAT3 signaling

Recent advances in the development of anti-inflammatory agents have improved their therapeutic outcome in inflammatory bowel disease (IBD), however, the presence of side effects and limited effectiveness hinder their widespread use. Therefore, novel compounds with strong anti-inflammatory efficacy are still required. In this study, we investigated the anti-inflammatory effect and potential mechanisms of Gynostemma pentaphyllum (Thunb.) Makino saponins (GpS), a major component of the herbal medicine widely used in Asian countries. In in vitro studies, we demonstrated that GpS dose dependently suppressed activation of macrophages, one of the main effectors in IBD. GpS also suppressed cytokine production and the activation of NF-κB and STAT3 signaling in lipopolysaccharide-induced macrophages, without affecting their viability. Further in vivo studies demonstrated that GpS could ameliorate the weight loss, increased disease activity index, colon shortening and histological damage associated with dextran sulfate sodium (DSS)-induced colitis in mice. In agreement with results from our in vitro experiments, GpS suppressed cytokine production and activation of NF-κB and STAT3 signaling in the colons of DSS-induced mice.

In this study, we present for the first time, evidence of the therapeutic effect of GpS in IBD, highlighting its potential as an effective therapeutic against the disease.

Gypenosides induce cell death and alter gene expression in human oral cancer HSC-3 cells

Gypenosides (Gyp), the primary components of Gynostemma pentaphyllum Makino, have long been used as a Chinese herbal medicine. In the present study, the effects of Gyp on cell viability, the cell cycle, cell apoptosis, DNA damage and chromatin condensation were investigated in vitro using human oral cancer HSC-3 cells. The results of the present study indicated that Gyp induces cell death, G2/M phase arrest and apoptosis in HSC-3 cells in a dose-dependent manner. It was also demonstrated that Gyp decreased the depolarization of mitochondrial membrane potential in a time-dependent manner. A cDNA microarray assay was performed and the results indicated that a number of genes were upregulated following Gyp treatment. The greatest increase was a 75.42-fold increase in the expression of GTP binding protein in skeletal muscle. Levels of the following proteins were also increased by Gyp: Serpine peptidase inhibitor, clade E, member 1 by 20.25-fold; ras homolog family member B by 18.04-fold, kelch repeat and BTB domain containing 8 by 15.22-fold; interleukin 11 by 14.96-fold; activating transcription factor 3 by 14.49-fold; cytochrome P450, family 1 by 14.44-fold; ADP-ribosylation factor-like 14 by 13.88-fold; transfer RNA selenocysteine 2 by 13.23-fold; and syntaxin 11 by 13.08-fold. However, the following genes were downregulated by GYP: Six-transmembrane epithelial antigen of prostate family member 4, 14.19-fold; γ-aminobutyric acid A receptor by 14.58-fold; transcriptional-regulating factor 1 by 14.69-fold; serpin peptidase inhibitor, clade B, member 13 by 14.71-fold; apolipoprotein L 1 by 14.85-fold; follistatin by 15.22-fold; uncharacterized LOC100506718; fibronectin leucine rich transmembrane protein 2 by 15.61-fold; microRNA 205 by 16.38-fold; neuregulin 1 by 19.69-fold; and G protein-coupled receptor 110 by 22.05-fold. These changes in gene expression illustrate the effects of Gyp at the genetic level and identify potential targets for oral cancer therapy.

Gypenoside inhibits interleukin-1β-induced inflammatory response in human osteoarthritis chondrocytes

Gypenoside (GP), the main active ingredient of Gynostemma pentaphyllum, possesses a variety of pharmacological capacities including anti-inflammation, anti-oxidation, and anti-tumor. However, the effects of GP on IL-1β-stimulated human osteoarthritis (OA) chondrocytes are still unknown. Therefore, this study aimed to investigate the anti-inflammatory effects of GP on IL-1β-stimulated human OA chondrocytes and explore the possible mechanism. Our results showed that GP dose-dependently inhibited IL-1β-induced NO and PGE2 production in human OA chondrocytes. In addition, treatment of GP inhibited the expression of MMP3 and MMP13, which was increased by IL-1β. Finally, we found that pretreatment of GP obviously suppressed NF-κB activation in IL-1β-stimulated human OA chondrocytes. Taken together, the results demonstrated that GP has chondro-protective effects, at least in part, through inhibiting the activation of NF-κB signaling pathway in human OA chondrocytes. Thus, these findings suggest that GP may be considered as an alternative therapeutic agent for the management of OA patients.

Mechanism underlying protective effect of gypenosides against type 2 diabetes mellitus and nonalcoholic fatty liver disease in rats

AIM

To explore the mechanism underlying protective effect of gypenosides (GPS) against type 2 diabetes mellitus and nonalcoholic fatty liver disease (T2DM-NAFLD) in rats.

METHODS

Sixty rats were randomly divided into five groups: blank control group, T2DM-NAFLD model group, low dose GPS group, medium dose GPS group, and high dose GPS group. The efficacy was confirmed by histopathology, and the expression of tumor necrosis factor-α (TNF-α) and nuclear factor-κB (NF-κB) in the liver was analyzed by immunohistochemistry. In addition, the expression of peroxisome proliferator activated receptor gamma (PPARγ) and cytochrome P4501A1 (CYP4501A1) mRNAs was detected by RT-PCR.

RESULTS

Immunohistochemical study showed that the expression of TNF-α and NF-κB was significantly reduced by GPS, in a dose-dependent manner. The expression of PPARγ and CYP4501A1 mRNAs measured by RT-PCR was also significantly down-regulated by GPS. Moreover, GPS decreased the infiltration of liver fats and reversed the histopathological changes in a dose-dependent manner.

CONCLUSION

GPS protects against T2DM-NAFLD by down-regulating the expression of TNF-α, NF-κB, PPARγ and CYP4501A1.

Gypenoside Attenuates β Amyloid-Induced Inflammation in N9 Microglial Cells via SOCS1 Signaling

Reducing β amyloid- (Aβ-) induced microglial activation is believed to be effective in treating Alzheimer's disease (AD). Microglia can be activated into classic activated state (M1 state) or alternative activated state (M2 state), and the former is harmful; in contrast, the latter is beneficial. Gypenoside (GP) is the major bioactive constituent of Gynostemma pentaphyllum, a traditional Chinese herb medicine. In this study, we hypothesized that GP attenuates Aβ-induced microglial activation by ameliorating microglial M1/M2 states, and the process may be mediated by suppressor of cell signaling protein 1 (SOCS1). In this study, we found that Aβ exposure increased the levels of microglial M1 markers, including iNOS expression, tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 releases, and coadministration of GP reversed the increase of M1 markers and enhanced the levels of M2 markers, including arginase-1 (Arg-1) expression, IL-10, brain-derived neurotrophic factor (BDNF), and glial cell-derived neurotrophic factor (GDNF) releases in the Aβ-treated microglial cells. SOCS1-siRNA, however, significantly abolished the GP-induced effects on the levels of microglial M1 and M2 markers. These findings indicated that GP attenuates Aβ-induced microglial activation by ameliorating M1/M2 states, and the process may be mediated by SOCS1.

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.

Chinese Herbal Compounds for the Prevention and Treatment of Atherosclerosis: Experimental Evidence and Mechanisms

Atherosclerosis is a leading cause of disability and death worldwide. Research into the disease has led to many compelling hypotheses regarding the pathophysiology of atherosclerotic lesion formation and the resulting complications such as myocardial infarction and stroke. Herbal medicine has been widely used in China as well as other Asian countries for the treatment of cardiovascular diseases for hundreds of years; however, the mechanisms of action of Chinese herbal medicine in the prevention and treatment of atherosclerosis have not been well studied. In this review, we briefly describe the mechanisms of atherogenesis and then summarize the research that has been performed in recent years regarding the effectiveness and mechanisms of antiatherogenic Chinese herbal compounds in an attempt to build a bridge between traditional Chinese medicine and cellular and molecular cardiovascular medicine.

Mechanism of action of gypenosides on type 2 diabetes and non-alcoholic fatty liver disease in rats

AIM: To explore the mechanism of action of gypenosides (GPs) on type 2 diabetes mellitus and non-alcoholic fatty liver disease (T2DM-NAFLD) in rats.

METHODS: Sixty rats were randomly divided into a healthy group, an untreated disease model group and GP-treatment groups. The study involved the evaluation of biochemical parameters, including serum aspartate transaminase (AST), alanine transferase (ALT), blood glucose (BG), triglycerides (TG) and total cholesterol (TC). Additionally, the protective effect of the treatments were confirmed histopathologically and the expression of TNF-α and NF-κB in the rat liver was analyzed using immunohistochemistry. The expression of proliferator-activated receptor gamma (PPARγ) and cytochrome P₄₅₀ (CYP₄₅₀) 1A1 mRNA was determined by quantitative RT-PCR.

RESULTS: GP treatments at oral doses of 200, 400, and 800 mg/kg per day significantly decreased the levels of serum AST and ALT (P < 0.05, P < 0.01), especially at the dose of 800 mg/kg per day. To a similar extent, GP at 800 mg/kg per day reduced the levels of BG (4.19 ± 0.47, P < 0.01), TG (80.08 ± 10.05, P < 0.01), TC (134.38 ± 16.39, P < 0.01) and serum insulin (42.01 ± 5.04, P < 0.01). The expression of TNF-α and NF-κB measured by immunohistochemistry was significantly reduced by GPs in a dose-dependent manner, and the expression of PPARγ and CYP₄₅₀1A1 mRNA, as measured using quantitative real-time PCR, were significantly down-regulated by GPs. Moreover, GPs decreased the infiltration of liver fats and reversed the histopathological changes in a dose-dependent manner.

CONCLUSION: This study suggests that GPs have a protective effect against T2DM-NAFLD by down-regulating the expression of TNF-α and NF-κB proteins, and PPARγ and CYP₄₅₀1A1 mRNAs.

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.

Hypoglycemic effect of Gynostemma pentaphyllum saponins by enhancing the Nrf2 signaling pathway in STZ-inducing diabetic rats

Gynostemma pentaphyllum (GP) is a natural plant resources for diabetes therapy, however, there is little research on the mechanisms of GP. The present study was undertaken to characterize if G. pentaphyllum saponins (GPs) is the principal active compound of GP responsible for anti-diabetes, and to examine the relativity between blood glucose modulate and antioxidation. The GPs-treated streptozotocin diabetic rats had a more effective hypoglycemic status than those of diabetic control rats, which also ameliorate dyslipidemia. GPs has increased SOD and GSH-px activities, and the spleen and thymus indexes in diabetic rats. The insulin levels in the GPs-treated groups were significantly higher than diabetic control group. Our finding provides a new insight into the application of GPs for the treatment of oxidative stress related diseases.

Anti-cancer effect and the underlying mechanisms of gypenosides on human colorectal cancer SW-480 cells

BACKGROUND

Gypenosides (Gyp), the main components from Gynostemma pentaphyllum Makino, are widely used in traditional Chinese medicine. The present study aimed to investigate the anti-cancer effect and the underlying mechanisms of Gyp on human colorectal cancer cells SW-480.

MATERIALS AND METHODS

The inhibitory effect of Gyp on SW-480 cells was evaluated by MTT assay. Apoptotic cell death was detected by nuclear Hoechst 33342 staining and DNA fragmentation analysis. Apoptosis was analyzed using Annexin V-PE/7-amino-actinomycin D staining. Cell membrane integrity was evaluated with flow cytometry following PI staining. Changes of mitochondrial membrane potential (Δψm) were detected through flow cytometry analysis of rhodamine 123 (Rh123). The role of reactive oxygen species (ROS) in Gyp induced cell death was investigated by intracellular ROS generation and general ROS scavenger. Wound-healing assay was carried out to investigate Gyp-inhibited migration of SW-480 cells in vitro. Additionally, the alterations in F-actin microfilaments were analyzed by FITC-labeled phalloidin toxin staining and the morphological changes were evaluated under scanning electron microscope (SEM).

RESULTS

After the Gyp treatment, the plasma membrane permeability of SW-480 cell was increased, Δψm was decreased significantly, the level of intracellular ROS level was increased, DNA fragmentation and apoptotic morphology were observed. Cells treated with Gyp exert serious microfilament network collapse as well as the significant decrease in the number of microvilli. Gyp induced the changes of cell viability, cell migration, intracellular ROS generation and nuclear morphology were alleviated obviously by NAC.

CONCLUSION

The results in this study implied that ROS play an important role in Gyp induced cell toxicity and apoptosis, and the mitochondria damage may be upstream of ROS generation post Gyp treatment. The findings of the present study provide new evidences for anti-tumor mechanisms by which Gyp induces apoptosis in vitro.

Determination by UPLC-MS of four dammarane-type saponins from heat-processed Gynostemma pentaphyllum

Heat-processed Gynostemma pentaphyllum and its main dammaran-type saponins, gypenoside L, gypenoside LI, damulin B, and damulin A, possess non-small cell lung carcinoma A549 cell inhibitory activity. We established in this study a method by ultra-high performance liquid chromatography with tandem mass spectrometry for determination of the saponins and also investigated their content change in heat-processed G. pentaphyllum. The main saponins increased with increasing heating temperature and time. Further investigation showed that they were produced from gypenoside XLVI and gypenoside LVI by undergoing hydrolysis during the heat treatment.

The Effect of Gynostemma pentaphyllum Extract on Mouse Dermal Fibroblasts

Background. The objective of this paper is to demonstrate the effect of Gynostemma pentaphyllum extract on mouse dermal fibroblasts. Recent studies have shown that this plant may possess great antioxidant properties, which can be very beneficial in combating oxidative stress. Methods. Gynostemma pentaphyllum extract was prepared and mouse dermal fibroblasts were obtained and cultured as per our laboratory protocols. Twelve samples of cells were cultured under the same conditions and both negative and positive controls were established. Induction of oxidative stress was carried out using ultraviolet C (UVC) light. Viable cell count was carried out, using microscopy. The analysis of the overall results was processed using SPSS version 16.0. Results. Statistical analysis showed strong positive correlation between the concentration of Gynostemma pentaphyllum and the mean duration of cell viability (rs = 1), with a high level of statistical significance (P < 0.01). Likewise, strong positive correlation existed between trials of cell viability (rs = 0.988–1), with statistical significance (P < 0.01). Conclusion. Gynostemma pentaphyllum extract prolongs viability of mouse dermal fibroblasts damaged by UVC light-induced oxidative stress. The results show the potential benefits of this extract on dermal cell aging.

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.

Antiproliferation and anti-migration induced by gypenosides in human colon cancer SW620 and esophageal cancer Eca-109 cells

Gypenosides (Gyp), found in Gynostemma pentaphyllum Makino, has attracted more attention owing to its wide bioactivities. However, the effects of Gyp on esophageal cancer cells and colon cancer cells are still unknown. The present study was to investigate the possible anti-proliferative and anti-migration activity of Gyp on human colon cancer cells SW620 and esophageal cancer cells Eca-109. Cell viability was evaluated using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell membrane integrity was evaluated using flow cytometry following propidium iodide staining. Apoptotic cell death was determined by nuclear 4′-6-diamidino-2-phenylindole staining. Generation of intracellular reactive oxygen species (ROS) and changes in mitochondrial membrane potential (Δ ψm) was analyzed by flow cytometry using 2′,7′-dichlorofluorescein–diacetate and rhodamine 123 staining, respectively. Wound healing assay was carried out to investigate Gyp-inhibited migration of SW620 and Eca-109 cells. The results indicated that Gyp inhibited cell proliferation and migration in SW620 and Eca-109 cells in dose- and time-dependent manner. Gyp elevated intracellular ROS level, decreased the Δ ψm, and induced apoptotic morphology such as cell shrinkage and chromatin condensation, suggesting oxidative stress and mitochondria-dependent cell apoptosis that might be involved in Gyp-induced cell viability loss in SW620 and Eca-109 cells. The findings indicate Gyp may have valuable application in clinical colon cancer and esophageal cancer treatments.

Restoration of electric footshock-induced immunosuppression in mice by Gynostemma pentaphyllum components

The immunomodulatory effects of the ethanol extract of Gynostemma pentaphyllum (GP-EX) were examined in electric footshock (EFS)-stressed mice. The mice were orally administered various doses of GP-EX for 7 days before exposure to EFS (duration: 3 min, interval: 10 s, intensity: 2 mA) once a day from day 8 for 14 days with continuous daily feeding of GP-EX. Oral administration of GP-EX to mice prevented EFS stress-induced immunosuppression as determined by the lymphoid organ (thymus and spleen) weight and cellularity. In addition, oral administration of GP-EX restored EFS-suppressed functional properties of mature lymphocytes in terms of concanavalin A-induced proliferation of splenocytes and lipopolysaccharide-induced cytokine production (TNF-α, IL-1β). Furthermore, we found that mice that were orally administered with GP-EX generated much more potent ovalbumin-specific cytotoxic T lymphocyte responses upon intravenous ovalbumin injection compared to the untreated controls. These results demonstrate that oral administration of the ethanol extract of Gynostemma pentaphyllum could increase host defense in immunocompromised situations such as stress-induced immunosuppression.

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.

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.

Gypenosides suppress growth of human oral cancer SAS cells in vitro and in a murine xenograft model: the role of apoptosis mediated by caspase-dependent and caspase-independent pathways

PURPOSE

Gypenosides (Gyp) are the major components of Gynostemma pentaphyllum Makino. The authors investigated the effects of Gyp on cell morphology, viability, cell cycle distribution, and induction of apoptosis in human oral cancer SAS cells and the determination of murine SAS xenograft model in vivo.

EXPERIMENTAL DESIGN

Flow cytometry was used to quantify the percentage of viable cells; cell cycle distribution; sub-G1 phase (apoptosis); caspase-3, -8, and -9 activity; reactive oxygen species (ROS) production, intracellular Ca(2+) determination; and the level of mitochondrial membrane potential (ΔΨ(m)). Western blotting was used to examine levels of apoptosis-associated proteins, and confocal laser microscopy was used to examine the translocation of proteins in cells.

RESULTS

Gyp induced morphological changes, decreased the percentage of viable cells, caused G0/G1 phase arrest, and triggered apoptotic cell death in SAS cells. Cell cycle arrest induced by Gyp was associated with apoptosis. The production of ROS, increased intracellular Ca(2+) levels, and the depolarization of ΔΨ(m) were observed. Gyp increased levels of the proapoptotic protein Bax but inhibited the levels of the antiapoptotic proteins Bcl-2 and Bcl-xl. Gyp also stimulated the release of cytochrome c and Endo G. Translocation of GADD153 to the nucleus was stimulated by Gyp. Gyp in vivo attenuated the size and volume of solid tumors in a murine xenograft model of oral cancer.

CONCLUSIONS

Gyp-induced cell death occurs through caspase-dependent and caspase-independent apoptotic signaling pathways, and the compound reduced tumor size in a xenograft nu/nu mouse model of oral cancer.

Chemical composition of five commercial Gynostemma pentaphyllum samples and their radical scavenging, antiproliferative, and anti-inflammatory properties

Five Gynostemma pentaphyllum (GP) samples were investigated and compared for their chemical compositions and their antioxidant, antiproliferative, and anti-inflammatory effects. Extracts (50% acetone, 75% ethanol, and 100% ethanol) of the five GP samples (GP1-5) differed in their total phenolic, saponin, and flavonoid contents and in their rutin and quercetin concentrations. The highest level of total flavonoids was 63.5 mg of rutin equiv/g in GP4, and the greatest total phenolic content was 44.3 mg of gallic acid equiv/g in GP1 with 50% acetone as the extraction solvent. GP2 had the highest total saponin content of 132.6 mg/g with 100% ethanol as the extraction solvent. These extracts also differed in their scavenging capacity against DPPH and hydroxyl radicals, although they all showed significant radical scavenging capacity. The 100% ethanol extracts also showed dose-dependently strong inhibition on IL-6 and Ptgs2 mRNA expression and weak inhibition on TNF-α mRNA expression. In addition, GP1 had the highest antiproliferative activity at 3.2 mg equiv/mL concentration in HT-29 human colon cancer cells. The results from this study will be used to promote the application of G. pentaphyllum for improving human health.

An Experimental Study on the Antileukemia Effects of Gypenosides In Vitro and In Vivo

Purpose. Gypenosides (Gyp), found in Gynostemma pentaphyllum Makino, have been used as folk medicine for centuries and have exhibited diverse pharmacological effects, including antileukemia effects in vitro and in vivo. In the present study, Gyp were used to examine effects on cell viability, cell cycle, and induction of apoptosis in vitro. They were administered in the diet to mice injected with WEHI-3 cells in vivo. Experimental design. Effects of Gyp on WEHI-3 cells were determined by flow cytometric assay and Western blotting. Results. Gyp inhibited the growth of WEHI-3 cells. These effects were associated with the induction of G0/G1 arrest, morphological changes, DNA fragmentation, and increased sub-G1 phase. Gyp promoted the production of reactive oxygen species, increased Ca2+ levels, and induced the depolarization of the mitochondrial membrane potential. The effects of Gyp were dose and time dependent. Moreover, Gyp increased levels of the proapoptotic protein Bax, reduced levels of the antiapoptotic proteins Bcl-2, and stimulated release of cytochrome c, AIF (apoptosis-inducing factor), and Endo G (endonuclease G) from mitochondria. The levels of GADD153, GRP78, ATF6-α, and ATF4-α were increased by Gyp, resulting in ER (endoplasmic reticular) stress in WEHI-3 cells. Oral consumption of Gyp increased the survival rate of mice injected with WEHI-3 cells used as a mouse model of leukemia. Conclusions. Results of these experiments provide new information on understanding mechanisms of Gyp-induced effects on cell cycle arrest and apoptosis in vitro and in an in vivo animal model.

Dammarane saponins from Gynostemma pentaphyllum

Dammarane-type saponins (1-7), together with five known compounds, were isolated from the aerial parts of Gynostemma pentaphyllum. Compounds 1-4, 6 and 7 induced the phosphorylation of ERK protein in primary rat cortical neurons, which indicates their potential neuroactivity. On the other hand, no induction of ERK phosphorylation was observed for HEK293 cells following treatment with saponins 1, 3, 4 and 7.

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

At low concentration H(2)O(2) is an important signal molecule in proliferation of tumour cells. We report about a study investigating the effect of an ethanolic extract from Gynostemma pentaphyllum on proliferation of C6 glioma tumour cells and cellular H(2)O(2) concentration. The proliferation of these cells was maximal at about 1 muM extracellular H(2)O(2). HPLC-finger prints of the extract revealed a set of saponines as essential components. In C6 glioma cells the extract caused increase in super oxide dismutase (SOD) activity, in the amount of SOD protein, and in cellular H(2)O(2) concentration. It inhibited cell proliferation and induced activation of caspase 3 as indication of apoptosis. No effect of the extract was observed on the proliferation of astrocytes of a primary cell culture. From these findings we suggest that the ethanolic extract from Gynostemma pentaphyllum may selectively shift the H(2)O(2) concentration to toxic levels exclusively in tumour cells due to increased SOD activity. It may have a high potency in cancer therapy and cancer prophylaxis.

Protection of hippocampal slices against hypoxia/hypoglycemia injury by a Gynostemma pentaphyllum extract

In transverse hippcampus slices a short period of hypoxia/hypoglycemia induced by perfusion with O(2)/glucose-free medium caused early loss and incomplete restoration of evoked field potentials to only 50% in the CA(1) region. We report about a study investigating the effect of an ethanolic Gynostemma pentaphyllum extract in this system. When given with reperfusion the extract completely protected the cells of the slices from functional injury. The extract also protected at the subcellular level isolated mitochondria which had been subjected to hypoxia/reoxygenation in combination with elevated extramitochondrial Ca(2+) concentration from functional injury. In isolated mitochondria the extract protected from Ca(2+)-induced opening of the mitochondrial permeability transition pore and reduced lipid peroxidation. Our data demonstrate that the ethanolic extract of Gynostemma pentaphyllum has a high potential to protect from ischemia/reperfusion injury. It should be beneficial as prophylactic nutrition supplement and during revascularization of arterial blood vessels from stroke and other ischemic events such as coronary occlusion.

GSH-dependent iNOS and HO-1 mediated apoptosis of human Jurkat cells induced by nickel(II)

The molecular mechanisms by which nickel compounds cause immune cytotoxicity are far from understood. Our preliminary data suggested that nickel(II) induced apoptosis in Jurkat cells by mitochondrial pathway, specifically via mitochondrial membrane potential dissipation and antiapoptotic gene bcl-2 down-regulation. The main goal of this study was to further investigate the toxicity of nickel, especially the induction of reactive oxygen species (ROS) on immune cells, which finally induced apoptosis. Nickel was found to induce glutathione (GSH) depletion in a dose- and time-dependent manner. When Jurkat cells were preincubated with antioxidant N-acetylcysteine (NAC), apoptosis was inhibited distinctly, which suggested that ROS played an initial role in nickel immune toxicity. Heme oxygenase-1 (HO-1) and Nitric oxide (NO) which may play an important role in regulatory and protective processes in cells were assayed upon nickel treatment. A significant increase in HO-1 mRNA levels was detected in nickel treated cells. We confirmed that reduction of Nitrate levels in Jurkat cells was due to down-regulation of inducible nitric oxide synthase (iNOS), not endothelial nitric oxide synthase (eNOS). Expression changes of HO-1 and iNOS were markedly blocked when Jurkat cells were preincubated with NAC, suggesting that ROS resulted in HO-1 and iNOS dysfunction in Jurkat cells. We supposed that the immune toxicity of nickel(II) was mainly due to GSH depletion and finally led to apoptosis, probably via changing the expression levels of HO-1 and iNOS in human T lymphocytes.

Potential hypoglycemic effect of an ethanol extract of Gynostemma pentaphyllum in C57BL/KsJ-db/db mice

This study was conducted to evaluate the antihyperglycemic effect of an extract of Gynostemma pentaphyllum Makino, containing standardized concentrations of gypenosides, in C57BL/KSJ-db/db mice. For 5 weeks, animals were provided a standard AIN-76 diet (normal control) with rosiglitazone (0.005%, wt/wt) or two different doses of G. pentaphyllum ethanol extract (GPE) of the plant leaves (0.0025% and 0.01%, wt/wt). After the experimental period, the blood glucose levels of the high-dose GPE- and rosiglitazone-supplemented groups were significantly lower than that of the control group. The plasma insulin concentrations of the GPE-supplemented mice were significantly elevated compared to the control group. The GPE and rosiglitazone treatments profoundly affected the intraperitoneal insulin tolerance test compared to the control group, but not the intraperitoneal glucose tolerance test. In the evaluation of effects on hepatic glucose metabolism, the ratios of glucokinase/glucose-6-phosphatase activities in the high-dose GPE- and rosiglitazone-supplemented groups were prominently higher than that of the control group. The histology of the pancreatic islets revealed that the insulin-positive beta-cell numbers were higher in the high-dose GPE- and rosiglitazone-supplemented groups than in the control group. These results suggest that the supplementation of high-dose GPE (0.01%) in the diet lowers the blood glucose level by altering the hepatic glucose metabolic enzyme activities.

Gypenosides induced G0/G1 arrest via CHk2 and apoptosis through endoplasmic reticulum stress and mitochondria-dependent pathways in human tongue cancer SCC-4 cells

Gypenosides (Gyp), a component of Gynostemma pentaphyllum Makino, was selected for examining the effects on the cell viability, cell cycle and induction of apoptosis in human tongue cancer SCC-4 cells. Gyp induced cytotoxicity (decreased the percentage of viable cells) in SCC-4 cells appeared to be associated with induction of cell cycle arrest (G0/G1 arrest), apoptotic cell death based on Gyp induced morphological changes and DNA fragmentation and increased the sub-G1 group in examined SCC-4 cells. The production of reactive oxygen species and Ca(2+) and the depolarization of mitochondrial membrane potential were observed, dose- and time-dependently, after treatment of SCC-4 cells with various concentrations of Gyp. Gyp inhibited the levels of the anti-apoptotic proteins Bcl-2 and Bcl-xl, but promoted the levels of the pro-apoptotic protein Bax. Western blotting showed the releases of cytochrome c and Endo G and both were also confirmed by confocal laser microscopic systems. The GADD153 moved to nuclei (nuclear translocation). In conclusion, Gyp induced ER stress and production of reactive oxygen species and Ca(2+), change the ratio of Bcl-2 and Bax, followed by the dysfunction of mitochondria, caused cytochrome c release, activation of caspase-3 before leading to apoptosis. These results provide information towards an understanding of the mechanisms by which Gyp induces cell cycle arrest and apoptosis in human tongue cancer cells.

Dammarane-type glycosides from Gynostemma pubescens

Triterpene saponins 1-8 were isolated from the aerial parts of Gynostemma pubescens. Among them, compounds 1-4, 8 possess carboxylic groups at both C-21 and C-29, 5 contains a carboxylic group at C-21 and an aldehyde function at C-29, whereas 6 and 7 contain carboxylic groups at C-21 and hydroxymethylene groups at C-29. Their structural elucidation was accomplished by extensive spectroscopic methods including application of 1D (1H, (13)C, (13)C DEPT) and 2D NMR experiments (HMQC, HMBC, HSQC), HRESIMS analysis, as well as by chemical degradation.

Gypenoside XLIX, a naturally occurring PPAR-alpha activator, inhibits cytokine-induced vascular cell adhesion molecule-1 expression and activity in human endothelial cells

Vascular cell adhesion molecule-1 (VCAM-1) is involved in several diseases, including chronic inflammation and atherosclerosis. Inhibition of the expression of this adhesion molecule is one of the key targets of anti-inflammatory, anti-cancer and anti-atherosclerotic drugs. Gynostemma pentaphyllum is a traditional medicine widely used in the treatment of respiratory inflammation, hyperlipidemia and atherosclerosis. However, its molecular mechanisms of action are still largely unknown. Gypenoside XLIX, a dammarane-type glycoside, is a prominent component of G. pentaphyllum. We have recently demonstrated Gypenoside XLIX to be a selective peroxisome proliferator-activated receptor (PPAR)-alpha activator. Here we demonstrate that Gypenoside XLIX concentration-dependently (0-300 microM) inhibited VCAM-1 promoter activity after induction by cytokine tumor necrosis factor (TNF)-alpha in human umbilical vein endothelial cells (HUVECs) transfected with promoter-reporter construct pVCAM-1-LUC. Furthermore, Gypenoside XLIX inhibited TNF-alpha-induced VCAM-1 mRNA and protein overexpression in HUVECs. The result of the enzyme immunoassay demonstrated that Gypenoside XLIX inhibited TNF-alpha-induced increase in cell surface VCAM-1 protein levels in HUVECs. In the present study we show that activities of Gypenoside XLIX are similar to those of Wy-14643, a potent synthetic PPAR-alpha activator. Furthermore, Gypenoside XLIX-induced inhibition on TNF-alpha-stimulated VCAM-1 promoter hyperactivity was completely abolished by a selective blocker of PPAR-alpha, MK-886. Thus, our findings suggest that Gypenoside XLIX inhibits cytokine-induced VCAM-1 overexpression and hyperactivity in human endothelial cells via a PPAR-alpha-dependent pathway. These data provide new insight into the rational basis of the use of the traditional Chinese herbal medicine G. pentaphyllum in the treatment of inflammatory and cardiovascular diseases, including atherosclerosis.

Gypenoside XLIX isolated from Gynostemma pentaphyllum inhibits nuclear factor-kappaB activation via a PPAR-alpha-dependent pathway

Nuclear factor (NF)-kappaB is important in the generation of inflammation. Besides regulating lipid metabolism, peroxisome proliferator-activated receptor (PPAR)-alpha activators also reduce NF-kappaB activation to terminate activation of inflammatory pathways. Gynostemma pentaphyllum (GP) has been used to treat various inflammatory diseases and hyperlipidemia. Here, we demonstrate that GP extract and one of its main components, Gypenoside XLIX (Gyp-XLIX) inhibited LPS-induced NF-kappaB activation in murine macrophages. Furthermore, Gyp-XLIX restored the LPS- and TNF-alpha-induced decrease in cytosolic I-kappaBalpha protein expression and inhibited the translocation of NF-kappaB(p65) to the nucleus in THP-1 monocyte and HUVEC cells. The inhibition of LPS- and TNF-alpha-induced NF-kappaB luciferase activity in macrophages was abolished by MK-886, a selective PPAR-alpha antagonist. GP extract and Gyp-XLIX (EC(50): 10.1 microM) enhanced PPAR-alpha luciferase activity in HEK293 cells transfected with the tK-PPREx3-Luc reporter plasmid and expression vectors for PPAR-alpha. Additionally, Gyp-XLIX specifically enhanced PPAR-alpha mRNA and protein expression in THP-1-derived macrophage cells. The selectivity of Gyp-XLIX for PPAR-alpha was demonstrated by the activation of only PPAR-alpha in HEK293 cells transfected with expression vectors for PPAR-alpha, PPAR-beta/delta or PPAR-gamma1 plasmids and in THP-1-derived macrophage naturally expressing all three PPAR isoforms. The present study demonstrates that Gyp-XLIX, a naturally occurring gynosaponin, inhibits NF-kappaB activation via a PPAR-alpha-dependent pathway.

A novel LXR-α activator identified from the natural product Gynostemma pentaphyllum

Liver X receptors (LXR) play an important role in cholesterol homeostasis by serving as regulatory sensors of cholesterol levels in tissues. The present study reports a novel LXR-alpha activator, (20S)-2alpha, 3beta, 12beta, 24(S)-pentahydroxydammar-25-ene 20-O-beta-d-glucopyranoside (TR1), a dammarane-type gynosaponin, isolated from the herbal medicine, Gynostemma pentaphyllum. Gynosaponin TR1 demonstrated greater selectivity toward activation of the LXR-alpha isoform than LXR-beta in HEK293 cells. TR1 selectively enhanced LXR-mediated transcriptional activation and protein expression of ABCA1 and apoE gene expression and secretion in THP-1-derived macrophages. The selectivity of TR1 for LXR-alpha was consistent with ligand docking studies, which showed favourable interaction of TR1 in the LXR-alpha-binding domain, whereas the presence of the sugar substituent interfered with binding to the LXR-beta site. Findings from the present study may provide insight into the development of pharmaceutical agents for treating atherosclerosis.

Neuroprotective herbs for stroke therapy in traditional eastern medicine

Traditional Eastern Medicine (TEM) has a long history in stroke therapy and its therapeutic efficacy has been confirmed by clinical studies. Extensive experience and abundant clinical data on TEM in stroke treatment have been accumulated over the past thousand years. Basic and clinical research in TEM constitutes a potentially rich source for new drug discovery and development with the integration of TEM and Western pharmacology. In recent years, many attempts have been made to document research data from extracts of composite formulas, single herbs, or single compounds from TEM herbs, according to orthodox pharmacological actions. This article reviews herbs and prescriptions that have been documented to have a neuroprotective effect in in vitro and in vivo ischemic model systems, and the neuroprotective compounds isolated from them. I also discuss the neuroprotective mechanisms of prescriptions, herbs, and single compounds relevant to the treatment of brain ischemia, including anti-oxidant, anti-excitotoxic, and anti-inflammatory effects.