Ginsenoside Rk3 modulates gut microbiota and regulates immune response of group 3 innate lymphoid cells to against colorectal tumorigenesis

The gut microbiota plays a pivotal role in the immunomodulatory and protumorigenic microenvironment of colorectal cancer(CRC).However,the effect of ginsenoside Rk3(Rk3)on CRC and gut microbiota remains unclear.Therefore,the purpose of this study is to explore the potential effect of Rk3 on CRC from the perspective of gut microbiota and immune regulation.Our results reveal that treatment with Rk3 significantly suppresses the formation of colon tumors,repairs intestinal barrier damage,and regulates the gut microbiota imbalance caused by CRC,including enrichment of probiotics such as Akkermansia muciniphila and Barnesiella intestinihominis,and clearance of pathogenic Desulfovibrio.Subsequent metabolomics data demonstrate that Rk3 can modulate the metabolism of amino acids and bile acids,particularly by upregulating glutamine,which has the potential to regulate the immune response.Furthermore,we elucidate the regulatory effects of Rk3 on chemokines and inflammatory factors associated with group 3 innate lymphoid cells(ILC3s)and T helper 17(Th17)signaling pathways,which inhibits the hyperactivation of the Janus kinase-signal transducer and activator of transcription 3(JAK-STAT3)signaling pathway.These results indicate that Rk3 modulates gut microbiota,regulates ILC3s immune response,and inhibits the JAK-STAT3 signaling pathway to suppress the development of colon tumors.More importantly,the results of fecal microbiota transplantation suggest that the inhibitory effect of Rk3 on colon tumors and its regulation of ILC3 immune responses are mediated by the gut microbiota.In summary,these findings emphasize that Rk3 can be utilized as a regulator of the gut microbiota for the prevention and treatment of CRC.

Crosstalk among Oxidative Stress,Autophagy,and Apoptosis in the Protective Effects of Ginsenoside Rb1 on Brain Microvascular Endothelial Cells:A Mixed Computational and Experimental Study

Objective Brain microvascular endothelial cells (BMECs) were found to shift from their usually inactive state to an active state in ischemic stroke (IS) and cause neuronal damage. Ginsenoside Rb1 (GRb1),a component derived from medicinal plants,is known for its pharmacological benefits in IS,but its protective effects on BMECs have yet to be explored. This study aimed to investigate the potential protective effects of GRb1 on BMECs. Methods An in vitro oxygen-glucose deprivation/reperfusion (OGD/R) model was established to mimic ischemia-reperfusion (I/R) injury. Bulk RNA-sequencing data were analyzed by using the Human Autophagy Database and various bioinformatic tools,including gene set enrichment analysis (GSEA),Gene Ontology (GO) classification and enrichment analysis,Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis,protein-protein interaction network analysis,and molecular docking. Experimental validation was also performed to ensure the reliability of our findings. Results Rb1 had a protective effect on BMECs subjected to OGD/R injury. Specifically,GRb1 was found to modulate the interplay between oxidative stress,apoptosis,and autophagy in BMECs. Key targets such as sequestosome 1 (SQSTM1/p62),autophagy related 5 (ATG5),and hypoxia-inducible factor 1-alpha (HIF-1α) were identified,highlighting their potential roles in mediating the protective effects of GRb1 against IS-induced damage. Conclusion GRbl protects BMECs against OGD/R injury by influencing oxidative stress,apoptosis,and autophagy. The identification of SQSTM1/p62,ATG5,and HIF-1α as promising targets further supports the potential of GRb1 as a therapeutic agent for IS,providing a foundation for future research into its mechanisms and applications in IS treatment.

Ginsenoside Rb1 induces hepatic stellate cell ferroptosis to alleviate liver fibrosis via the BECN1/SLC7A11 axis

Liver fibrosis is primarily driven by the activation of hepatic stellate cells(HSCs),a process associated with ferroptosis.Ginsenoside Rb1(GRb1),a major active component extracted from Panax ginseng,inhibits HSC activation.However,the potential role of GRb1 in mediating HSC ferroptosis remains unclear.This study examined the effect of GRb1 on liver fibrosis both in vivo and in vitro,using CCl4-induced liver fibrosis mouse model and primary HSCs,LX-2 cells.The findings revealed that GRb1 effectively inactivated HSCs in vitro,reducing alpha-smooth muscle actin(a-SMA)and type I collagen(Col1A1)levels.Moreover,GRb1 significantly alleviated CCl4-induced liver fibrosis in vivo.From a mechanistic standpoint,the ferroptosis pathway appeared to be central to the antifibrotic effects of GRb1.Specifically,GRb1 promoted HSC ferroptosis both in vivo and in vitro,characterized by increased glutathione depletion,malondialdehyde production,iron overload,and accumulation of reactive oxygen species(ROS).Intriguingly,GRb1 increased Beclin 1(BECN1)levels and decreased the System Xc-key subunit SLC7A11.Further experiments showed that BECN1 silencing inhibited GRb1-induced effects on HSC ferroptosis and mitigated the reduction of SLC7A11 caused by GRb1.Moreover,BECN1 could directly interact with SLC7A11,initiating HSC ferroptosis.In conclusion,the suppression of BECN1 counteracted the effects of GRb1 on HSC inactivation both in vivo and in vitro.Overall,this study highlights the novel role of GRb1 in inducing HSC ferroptosis and promoting HSC inactivation,at least partly through its modulation of BECN1 and SLC7A11.

GPCR-Gs mediates the protective effects of ginsenoside Rb1 against oxygen-glucose deprivation/re-oxygenation-induced astrocyte injury

Objectives:To investigate whether the protective actions of ginsenoside Rb1(Rb1)on astrocytes are mediated through the G_(s)-type G-protein-coupled receptor(GPCR-G_(s)).Methods:Primary astrocyte cultures derived from neonatal mouse brain were used.Astrocyte injury was induced via oxygen-glucose deprivation/re-oxygenation(OGD/R).Cell morphology,viability,lactate dehydrogenase(LDH)leakage,apoptosis,glutamate uptake,and brain-derived neurotrophic factor(BDNF)secretion were assessed to gauge cell survival and functionality.Western blot was used to investigate the cyclic adenosine monophosphate(cAMP)and protein kinase B(Akt)signaling pathways.GPCR-G_(s)-specific inhibitors and molecular docking were used to identify target receptors.Results:Rb1 at concentrations ranging from 0.8 to 5μM did not significantly affect the viability,glutamate uptake,or BDNF secretion in normal astrocytes.OGD/R reduced astrocyte viability,increasing their LDH leakage and apoptosis rate.It also decreased glutamate uptake and BDNF secretion by these cells.Rb1 had protective effects of astrocytes challenged by OGD/R,by improving viability,reducing apoptosis,and enhancing glutamate uptake and BDNF secretion.Additionally,Rb1 activated the cAMP and Akt pathways in these cells.When the GPCR-G_(s) inhibitor NF449 was introduced,the protective effects of Rb1 completely disappeared,and its activation of cAMP and Akt signaling pathways was significantly inhibited.Conclusion:Rb1 protects against astrocytes from OGD/R-induced injury through GPCR-G_(s) mediation.

Transcriptome-Wide Identification and Functional Analysis of PgSQE08-01 Gene in Ginsenoside Biosynthesis in Panax ginseng C.A.Mey.

Panax ginseng C.A.Mey.is an important plant species used in traditional Chinese medicine,whose primary active ingredient is a ginsenoside.Ginsenoside biosynthesis is not only regulated by transcription factors but also controlled by a variety of structural genes.Nonetheless,the molecular mechanism underlying ginsenoside biosynthesis has always been a topic in the discussion of ginseng secondary metabolites.Squalene epoxidase(SQE)is a key enzyme in the mevalonic acid pathway,which affects the biosynthesis of secondary metabolites such as terpenoid.Using ginseng transcriptome,expression,and ginsenoside content databases,this study employed bioinformatic methods to systematically analyze the genes encoding SQE in ginseng.We first selected six PgSQE candidates that were closely involved in ginsenoside biosynthesis and then identified PgSQE08-01 to be highly associated with ginsenoside biosynthesis.Next,we constructed the overexpression vector pCAMBIA3301-PgSQE08-01 and the RNAi vector pART27-PgSQE08-01 and transformed ginseng adventitious roots using Agrobacterium rhizogenes,to obtain positive hairy-root clones.Thereafter,quantitative reverse transcriptionpolymerase chain reaction and high-performance liquid chromatography were used to determine the expression of relevant genes and ginsenoside content,respectively.Then,we focused on the function of PgSQE08-01 gene,which was noted to be involved in ginsenoside biosynthesis.Thus,these findings not only provided a molecular basis for the identification of important functional genes in ginseng but also enriched genetic resources for the biosynthesis of ginsenosides using synthetic biology.

Effect of ginsenoside Rg1 on hematopoietic stem cells in treating aplastic anemia in mice via MAPK pathway

BACKGROUND Aplastic anemia(AA)presents a significant clinical challenge as a life-threatening condition due to failure to produce essential blood cells,with the current the-rapeutic options being notably limited.AIM To assess the therapeutic potential of ginsenoside Rg1 on AA,specifically its protective effects,while elucidating the mechanism at play.METHODS We employed a model of myelosuppression induced by cyclophosphamide(CTX)in C57 mice,followed by administration of ginsenoside Rg1 over 13 d.The invest-igation included examining the bone marrow,thymus and spleen for pathological changes via hematoxylin-eosin staining.Moreover,orbital blood of mice was collected for blood routine examinations.Flow cytometry was employed to identify the impact of ginsenoside Rg1 on cell apoptosis and cycle in the bone marrow of AA mice.Additionally,the study further evaluated cytokine levels with enzyme-linked immunosorbent assay and analyzed the expression of key proteins in the MAPK signaling pathway via western blot.RESULTS Administration of CTX led to significant damage to the bone marrow’s structural integrity and a reduction in hematopoietic cells,establishing a model of AA.Ginsenoside Rg1 successfully reversed hematopoietic dysfunction in AA mice.In comparison to the AA group,ginsenoside Rg1 provided relief by reducing the induction of cell apoptosis and inflammation factors caused by CTX.Furthermore,it helped alleviate the blockade in the cell cycle.Treatment with ginsenoside Rg1 significantly alleviated myelosuppression in mice by inhibiting the MAPK signaling pathway.CONCLUSION This study suggested that ginsenoside Rg1 addresses AA by alleviating myelosuppression,primarily through modulating the MAPK signaling pathway,which paves the way for a novel therapeutic strategy in treating AA,highlighting the potential of ginsenoside Rg1 as a beneficial intervention.

A novel cabazitaxel liposomes modified with ginsenoside Rk1 for cancer targeted therapy

Objective:In this study,we aim to enhance the anti-prostate cancer efficacy of cabazitaxel(CTX)and reduce its immunosuppression and systemic toxicity by developing CTX-loaded liposomes modified with ginsenoside Rk1(Rk1/CTX-Lip).Methods:Physical and chemical properties of Rk1/CTX-Lip were investigated.We evaluated the biological functions of Rk1/CTXLip,both in vitro and in vivo.A subcutaneous prostate cancer(RM-1)-bearing mouse model was established to study the efficacy of Rk1/CTX-Lip inhibition in tumors.Simultaneously,a Candida albicans infection model was established in tumor-bearing mice to study the infection-relieving efficacy of Rk1/CTX-Lip.Finally,biocompatibility and in vivo safety of Rk1/CTX-Lip were evaluated.Results:We successfully prepared Rk1/CTX-Lip,achieving high CTX encapsulation efficiency(97.24±0.75)%and physical stability.Rk1/CTX-Lip demonstrated evasion of macrophage phagocytosis,effective tumor tissue targeting,and a significant reduction(>50%)in average tumor volume compared with Chol/CTX-Lip.Moreover,it relieved the concurrent infection burden and effectively regulated immune organs and cells,demonstrating superior biocompatibility.Conclusion:Rk1/CTX-Lip presents a promising new therapy for prostate cancer and holds potential for relieving concurrent fungal infections in cancer patients with low immunity.

Ginsenoside Rk3 is a novel PI3K/AKT-targeting therapeutics agent that regulates autophagy and apoptosis in hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is the third leading cause of cancer death worldwide.Ginsenoside Rk3,an important and rare saponin in heat-treated ginseng,is generated from Rg1 and has a smaller molecular weight.However,the anti-HCC efficacy and mechanisms of ginsenoside Rk3 have not yet been characterized.Here,we investigated the mechanism by which ginsenoside Rk3,a tetracyclic triterpenoid rare ginsenoside,inhibits the growth of HCC.We first explored the possible potential targets of Rk3 through network pharmacology.Both in vitro(HepG2 and HCC-LM3 cells)and in vivo(primary liver cancer mice and HCC-LM3 subcutaneous tumor-bearing mice)studies revealed that Rk3 significantly inhibits the proliferation of HCC.Meanwhile,Rk3 blocked the cell cycle in HCC at the G1 phase and induced autophagy and apoptosis in HCC.Further proteomics and siRNA experiments showed that Rk3 regulates the phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)pathway to inhibit HCC growth,which was validated by molecular docking and surface plasmon resonance.In conclusion,we report the discovery that ginsenoside Rk3 binds to PI3K/AKT and promotes autophagy and apoptosis in HCC.Our data strongly support the translation of ginsenoside Rk3 into novel PI3K/AKT-targeting therapeutics for HCC treatment with low toxic side effects.

Ginsenoside Rb1 improves energy metabolism after spinal cord injury

Mitochondrial damage caused by oxidative stress and energy deficiency induced by focal ischemia and hypoxia are important factors that aggravate diseases.Studies have shown that ginsenoside Rb1 has neurotrophic and neuroprotective effects.However,whether it influences energy metabolism after spinal cord injury remains unclear.In this study,we treated mouse and cell models of spinal cord injury with ginsenoside Rb1.We found that ginsenoside Rb1 remarkably inhibited neuronal oxidative stress,protected mitochondria,promoted neuronal metabolic reprogramming,increased glycolytic activity and ATP production,and promoted the survival of motor neurons in the anterior horn and the recovery of motor function in the hind limb.Because sirtuin 3 regulates glycolysis and oxidative stress,mouse and cell models of spinal cord injury were treated with the sirtuin 3 inhibitor 3-TYP.When Sirt3 expression was suppressed,we found that the therapeutic effects of ginsenoside Rb1 on spinal cord injury were remarkably inhibited.Therefore,ginsenoside Rb1 is considered a potential drug for the treatment of spinal cord injury,and its therapeutic effects are closely related to sirtuin 3.

Ginsenoside Rg5 enhances the radiosensitivity of lung adenocarcinoma via reducing HSP90-CDC37 interaction and promoting client protein degradation

Ginsenoside Rg5 is a rare ginsenoside showing promising tumor-suppressive effects.This study aimed to explore its radio-sensitizing effects and the underlying mechanisms.Human lung adenocarcinoma cell lines A549 and Calu-3 were used for in vitro and in vivo analysis.Bioinformatic molecular docking prediction and following validation by surface plasmon resonance(SPR)technology,cellular thermal shift assay(CETSA),and isothermal titration calorimetry(ITC)were conducted to explore the binding between ginsenoside Rg5 and 90 kD heat shock protein alpha(HSP90a).The effects of ginsenoside Rg5 on HSP90-cell division cycle 37(CDC37)interaction,the client protein stability,and the downstream regulations were further explored.Results showed that ginsenoside Rg5 could induce cell-cycle arrest at the G1 phase and enhance irradiationinduced cell apoptosis.It could bind to HSP90a with a high affinity,but the affinity was drastically decreased by HSP90a Y61A mutation.Co-immunoprecipitation(Co-IP)and ITC assays confirmed that ginsenoside Rg5 disrupts the HSP90-CDC37 interaction in a dose-dependent manner.It reduced irradiation-induced upregulation of the HSP90-CDC37 client proteins,including SRC,CDK4,RAF1,and ULK1 in A549 cell-derived xenograft(CDX)tumors.Ginsenoside Rg5 or MRT67307(an IKKε/TBK1 inhibitor)pretreatment suppressed irradiation-induced elevation of the LC3-II/b ratio and restored irradiation-induced downregulation of p62 expression.In A549 CDX tumors,ginsenoside Rg5 treatment suppressed LC3 expression and enhanced irradiation-induced DNA damage.In conclusion,ginsenoside Rg5 may be a potential radiosensitizer for lung adenocarcinoma.It interacts with HSP90a and reduces the binding between HSP90 and CDC37,thereby increasing the ubiquitin-mediated proteasomal degradation of the HSP90-CDC37 client proteins.

Ginsenoside Rk2, a dehydroprotopanaxadiol saponin, alleviates alcoholic liver disease via regulating NLRP3 and NLRP6 inflammasome signaling pathways in mice

Heavy alcohol consumption results in alcoholic liver disease(ALD)with inadequate therapeutic options.Here,we first report the potential beneficial effects of ginsenoside Rk2(Rk2),a rare dehydroprotopanaxadiol saponin isolated from streamed ginseng,against alcoholic liver injury in mice.Chronic-plus-single-binge ethanol feeding caused severe liver injury,as manifested by significantly elevated serum aminotransferase levels,hepatic histological changes,increased lipid accumulation,oxidative stress,and inflammation in the liver.These deleterious effects were alleviated by the treatment with Rk2(5 and 30 mg/kg).Acting as an nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3(NLRP3)inhibitor,Rk2 ameliorates alcohol-induced liver inflammation by inhibiting NLRP3 inflammasome signaling in the liver.Meanwhile,the treatment with Rk2 alleviated the alcohol-induced intestinal barrier dysfunction via enhancing NLRP6 inflammasome in the intestine.Our findings indicate that Rk2 is a promising agent for the prevention and treatment of ALD and other NLPR3-driven diseases.

Comparative analysis of physicochemical properties,ginsenosides content andα-amylase inhibitory effects in white ginseng and red ginsen

Ginseng(Panax ginseng C.A.Meyer)as a common dietary adjunct is widely applied in Traditional Chinese Medicine due to its health-promoting properties,but the differences between white ginseng and red ginseng was rarely studied.In the present study,color parameters and scanning electron microscope(SEM)were determined to evaluate the differences of ginseng color and microstructure induced by processing procedure.Quantitative analysis of multi-components by a single-marker(QAMS)method and anti-α-amylase activity test were used to assess variations of chemical ingredients and pharmacological activity between white and red ginseng.Finally,molecular docking studies were carried out to screen out the most effective compound againstα-amylase.Results indicated that processing had a significant impact on the physicochemical properties and pharmacological activity of white and red ginseng.After processing,the color value of L*declined significantly.Red ginseng sample displayed a compact structure and presented of a gel layer on the surface compared to white ginseng.Additionally,the content of ginsenosides and the activity of anti-α-amylase decreased.The contents of total ginsenosides were positively correlated with the anti-α-amylase activities of ginseng,and ginsenoside Rb1 might be the most effective compound to inhibit the activity ofα-amylase.

Ginsenoside Rc:A potential intervention agent for metabolic syndrome

Ginsenoside Rc,a dammarane-type tetracyclic triterpenoid saponin primarily derived from Panax ginseng,has garnered significant attention due to its diverse pharmacological properties.This review outlined the sources,putative biosynthetic pathways,extraction,and quantification techniques,as well as the pharmacokinetic properties of ginsenoside Rc.Furthermore,this study explored the pharmacological effects of ginsenoside Rc against metabolic syndrome(MetS)across various phenotypes including obesity,diabetes,atherosclerosis,non-alcoholic fatty liver disease,and osteoarthritis.It also highlighted the impact of ginsenoside Rc on multiple associated signaling molecules.In conclusion,the anti-MetS effect of ginsenoside Rc is characterized by its influence on multiple organs,multiple targets,and multiple ways.Although clinical investigations regarding the effects of ginsenoside Rc on MetS are limited,its proven safety and tolerability suggest its potential as an effective treatment option.

Ginsenoside Rg1 protects against ischemia-induced neuron damage by regulating the rno-miRNA-27a-3p/PPARγaxis

A preliminary miRNA screening showed that expression levels of rno-miRNA-27a-3p were significantly increased in the serum and brain tissues of rats undergoing cerebral ischemia.In recent years,there is evidence of the protective capacity of the saponins extracted from panax ginseng and its primary active ingredient ginsenosideRg1oncerebral ischemic injury.Methods:Fetal rat neurons(FRNs)were cultured in glucose-and-serumfree medium and exposed to hypoxia to establish a cerebral ischemia model in vitro(oxygen and glucose deprivation model,OGD).Antioxidant indexes(CAT,SOD),inflammatory markers(MPO,TNF-αand IL-6),and the expression of apoptosis and proliferation associated proteins(NF kB-p65,Caspase 3-cleaved,BCL-2)were examined.Results:Pre-treatment of Rg1(30–100μg/mL)could effectively inhibit the decline of antioxidant indexes(CAT,SOD)and increase in inflammatory markers(MPO,TNF-αand IL-6),and effectively inhibited the apoptosis in FRNs induced by OGD in a gradient-dependent manner.The mechanism analysis showed that the role of Rg1 in protecting against ischemia-induced neuron damage depends on its indirect up-regulation of PPAR protein via suppression of rnomiRNA-27a-3p.Moreover,these effects of Rg1 could be reversed by exogenous rno-miRNA-27a-3p and PPAR gene silencing in FRNs exposed to OGD.Conclusion:To summarize,our study demonstrates that Rg1 could effectively attenuate neuronal damage caused by cerebral ischemia via the rno-miRNA-27a-3p/PPARγpathway.Further,clarification of the novel mechanism will certainly improve our previous understanding of the role of Rg1 and enhancing its level in treatments for alleviating ischemic brain injury.

Ginsenoside compound-K attenuates OVX-induced osteoporosis via the suppression of RANKL-induced osteoclastogenesis and oxidative stress

Osteoporosis(OP),a systemic and chronic bone disease,is distinguished by low bone mass and destruction of bone microarchitecture.Ginsenoside Compound-K(CK),one of the metabolites of ginsenoside Rb1,has anti-aging,anti-inflammatory,anti-cancer,and hypolipidemic activities.We have demonstrated CK could promote osteogenesis and fracture healing in our previous study.However,the contribution of CK to osteoporosis has not been examined.In the present study,we investigated the effect of CK on osteoclastogenesis and ovariectomy(OVX)-induced osteoporosis.The results showed that CK inhibited receptor activator for nuclear factor-κB ligand(RANKL)-mediated osteoclast differentiation and reactive oxygen species(ROS)activity by inhibiting the phosphorylation of NF-κB p65 and oxidative stress in RAW264.7 cells.In addition,we also demonstrated that CK could inhibit bone resorption using bone marrow-derived macrophages.Furthermore,we demonstrated that CK attenuated bone loss by suppressing the activity of osteoclast and alleviating oxidative stress in vivo.Taken together,these results showed CK could inhibit osteoclastogenesis and prevent OVX-induced bone loss by inhibiting NF-κB signaling pathway.

Ginsenoside F1 administration promotes UCP1-dependent fat browning and ameliorates obesity-associated insulin resistance

Obesity-induced type 2 diabetes is mainly due to excessive free fatty acids leading to insulin resistance.Increasing thermogenesis is regarded as an effective strategy for hypolipidemia and hypoglycemia.Ginsenoside is a natural active component in Panax ginseng C.A.Meyer,and some of them enhance thermogenesis.However,there are few studies on the mechanism and target of ginsenosides enhancing thermogenesis.Using thermogenic protein uncoupling protein 1(UCP1)-luciferase reporter assay,we identifi ed ginsenoside F1 as a novel UCP1 activator in the ginsenosides library.Using pull down assay and inhibitor interference,we found F1 binds toβ3-adrenergic receptors(β3-AR)to enhance UCP1 expression via cAMP/PKA/CREB pathway.We also investigated the ability of F1 on energy metabolism in obesity-induced diabetic mice,including body weight,body composition and energy expenditure.The results of proteomics showed that F1 signifi cantly up-regulated thermogenesis proteins and lipolytic proteins,but down-regulated fatty acid synthesis proteins.Ginsenoside F1 increased thermogenesis and ameliorated insulin resistance specifi cally by promoting the browning of white adipose tissue in obese mice.Additionally,ginsenoside F1 improves norepinephrine-induced insulin resistance in adipocytes and hepatocytes,and shows a stronger mitochondria respiration ability than norepinephrine.These fi ndings suggest that ginsenoside F1 is a promising lead compound in the improvement of insulin resistance.

Protective effect of ginsenoside Rg1 on 661W cells exposed to oxygen-glucose deprivation/reperfusion via keap1/nrf2 pathway

AIM:To construct an in vitro model of oxygen-glucose deprivation/reperfusion(OGD/R)induced injury to the optic nerve and to study the oxidative damage mechanism of ischemia-reperfusion(I/R)injury in 661W cells and the protective effect of ginsenoside Rg1.METHODS:The 661W cells were treated with different concentrations of Na2S2O4 to establish OGD/R model in vitro.Apoptosis,intracellular reactive oxygen species(ROS)levels and superoxide dismutase(SOD)levels were measured at different time points during the reperfusion injury process.The injury model was pretreated with graded concentrations of ginsenoside Rg1.Real-time polymerase chain reaction(PCR)was used to measure the expression levels of cytochrome C(cyt C)/B-cell lymphoma-2(Bcl2)/Bcl2 associated protein X(Bax),heme oxygenase-1(HO-1),caspase9,nuclear factor erythroid 2-related factor 2(nrf2),kelch-like ECH-associated protein 1(keap1)and other genes.Western blot was used to detect the expression of nrf2,phosphorylated nrf2(pnrf2)and keap1 protein levels.RESULTS:Compared to the untreated group,the cell activity of 661W cells treated with Na2S2O4 for 6 and 8h decreased(P<0.01).Additionally,the ROS content increased and SOD levels decreased significantly(P<0.01).In contrast,treatment with ginsenoside Rg1 reversed the cell viability and SOD levels in comparison to the Na_(2)S_(2)O_(4)treated group(P<0.01).Moreover,Rg1 reduced the levels of caspase3,caspase9,and cyt C,while increasing the Bcl2/Bax level.These differences were all statistically significant(P<0.05).Western blot analysis showed no significant difference in the protein expression levels of keap1 and nrf2 with Rg1 treatment,however,Rg1 significantly increased the ratio of pnrf2/nrf2 protein expression compared to the Na_(2)S_(2)O_(4)treated group(P<0.001).CONCLUSION:The OGD/R process is induced in 661W cells using Na_(2)S_(2)O_(4).Rg1 inhibits OGD/R-induced oxidative damage and alleviates the extent of apoptosis in 661W cells through the keap1/nrf2 pathway.These results suggest a potential protective effect of Rg1 against retinal I/R injury.

Microbiological Transformation of Ginsenoside Rg_1

Forty-nine microbial strains were used to screen their ability for the microbiological transforma-tion of ginsenoside Rg1. Aspergillus niger (3.1858) and Absidia coerulea (3.3538) were found to convert ginsenoside Rg1 efficiently to less polar metabolites. Preparative scale transformation with both fungi Absidia coerulea (3.3538) and Aspergillus niger (3.1858) have resulted in the production of one same metabolite (MT1). Its structure was char-acterized as 6-O-b-D-glucopyranosyl-20(S)-protopanaxatriol (Ginsenoside Rh1) on the basis of its TOF-MS and 1H, 13C NMR spectral data. The biotransformation kinetic curves for Ginsenoside Rg1 and MT1 were reported for the first time, and the biotransformation pathway was proposed.

Enrichment of the less polar ginsenoside (Rg3) from ginseng grown in New Zealand by post-harvest processing and extraction

Background:Previous studies showed that New Zealand-grown ginseng contains an abundance of ginsenosides and that rare less polar ginsenosides,such as Rg3,exhibit more pharmacological activities than polar ginsenosides,which are the major components of ginseng.Methods:The ginsenoside profile of New Zealand-grown Panax ginseng was manipulated by treatment with acetic acid,sodium hydroxide,pH,and high temperature.The abundance of 23 ginsenosides extracted by different treatments was quantified using high-performance liquid chromatography.Results:Treatment with 0.5 mol/L acetic acid can stimulate the degradation of polar ginsenosides to less polar ginsenosides(5.6%Rg3 was accumulated,P<0.0001).Furthermore,when ginseng root was treated at 121℃ for 100 min in a pH 3.0 acetic acid aqueous solution,the majority of the polar ginsenosides were converted into less polar ginsenosides.Specifically,83.46±3.69%(P=0.0360)of the less polar ginsenosides and 41.01±2.39%(P=0.0412)of Rg3 were enriched.In contrast,alkali treatment did not convert the polar ginsenosides into less polar ginsenosides at mild temperature and less conversion was observed compared with acid treatment at high temperature.Conclusion:This is the first attempt to manipulate the ginsenoside profile of New Zealand-grown ginseng.The conditions(high temperature with low pH)may be modified to produce and enrich the less polar ginsenoside fraction(especially Rg3)from the total ginseng extract.

Ocotillone-type Ginsenoside from Leaves of Panax ginseng

An ocotillone type ginsenoside, together with 2 known ginsenosides was isolated from leaves of Panax ginseng and identified as pseudoginsenoside RT 5 on the basis of chemical and physicochemical evidences. It has been so far the first example of ocotillone type ginsenoside discovered in Panax ginseng and its plausible biotransformation pathway also discussed.