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.

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.

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.

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.

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 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 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.

Effect of Ginsenoside-Rb_1 on Cardiomyocyte Apoptosis after Ischemia and Reper fusion in Rats

The effect of ginsenoside Rb 1 on cardiomyocyte apotosis after ischemia (30 min ) and reperfusion (6 h) in rats was observed. The ischemia/ reperfusion heart mo del was established by ligating left anterior descending branch of coronary arte ry in Wistar rats. The apoptotic cardiomyocytes were examined under transmission electron microscopy and counted by in situ nick end labeling (TUNEL) method and light microscopy. Results showed that (1) The apoptotic cardiomyocytes were found in ischemic regions in the ischemia/reperfusion group, but not in the sh am oper ating group under transmission electron microscopy; (2) The number of apoptotic cells were 134.45±45.61/field in the ischemia/reperfusion group, 0/field in the sham operating group and 51.65±13.71/field in the ginsenoside Rb 1 treated group. The differences were significant among the three groups ( P <0.01). It was concluded that myocardial ischemia reperfusion could induce cardiomyocyte a poptosis, and ginsenoside Rb 1 could significantly inhibit cardiomyocyte apopto sis induced by ischemia reperfusion in rats, indicating that ginsenoside Rb 1 could inhibit cardiomyocyte apoptosis induced by ischemia reperfusion, thus alleviating ischemia reperfusion injury.

Influence of ginsenoside Rg1, a panaxatriol saponin from Panax notoginseng, on renal fibrosis in rats with unilateral ureteral obstruction

Total saponins of Panax notoginseng （PNS） have been shown to ameliorate renal interstitial fibrosis. Ginsenoside Rg 1, a panaxatriol saponin, is one of the major active molecules from PNS. The present study was undertaken to investigate the effect of ginsenoside Rgl on renal fibrosis in rats with unilateral ureteral obstruction （UUO）. The rats were randomly divided into 3 groups： sham-operation （n=15）, UUO （n=15） and UUO with ginsenoside Rgl treatment （n=15, 50 mg per kg body weight, intraperitoneally （i.p.） injected）. The rats were sacrificed on Days 7 and 14 after the surgery. Histological examination demonstrated that ginsenoside Rgl significantly inhibited interstitial fibrosis including tubular injury as well as collagen deposition, u-smooth muscle actin （α-SMA） and E-cadherin are two markers of tubular epithelial-myofibroblast transition （TEMT）. Interestingly, ginsenoside Rgl notably decreased α-SMA expression and simultaneously enhanced E-cadherin expression. The messenger RNA （mRNA） of transforming growth factor-β1 （TGF-β1）, a key mediator to regulate TEMT, in the obstructed kidney increased dramatically, but was found to decrease significantly after administration of ginsenoside Rg 1. Further study showed that ginsenoside Rgl considerably decreased the levels of both active TGF-β1 and phosphorylated Smad2 （pSmad2）. Moreover, ginsenoside Rgl substantially suppressed the expression of thrombospondin-1 （TSP-1）, a cytokine which can promote the transcription of TGF-β1 mRNA and the activation of latent TGF-β1. These results suggest that ginsenoside Rgl inhibits renal interstitial fibrosis in rats with UUO. The mechanism might be partly related to the blocking of TEMT via suppressing the expression of TSP-1.

High efficiency production of ginsenoside compound K by catalyzing ginsenoside Rb1 using snailase

The rare ginsenoside Compound K （C-K） is attracting more attention because of its good physiological activity and urgent need. There are many pathways to obtain ginsenoside C-K, including chemical and biological methods. Among these, the conversion of PPD-type ginsenosides by enzymatic hydrolysis is a trend due to its high efficiency and mild conditions. For effectively extracting from the other panaxadiol saponins, the conversion process for ginsenoside C-K was investigated using snailases in this study. The univariate experimental design and response surface methodology were used to determine the optimal hydrolysis conditions for the conversion of ginsenoside Rbl into ginsenoside C-K by snailases. The optimum conditions were as follows： pH 5,12, temperature 51 ℃, ratio of snailase/substrate 0.21, and reaction time 48 h. On the basis of these parameters, the addition of 1.0 mmol· L- 1 ferric ion was found to significantly improve the enzymolysis ofsnailases for the first time. With the above conditions, the maximum conversion rate reached 89.7%, suggesting that the process can obviously increase the yield of ginsenoside C-K. The bioassay tests indicated that the ginsenoside C-K showed anti-tumor activity in a series of tumor cell lines. Based on these results, we can conclude that the process of rare ginsenoside C- K production by enzymolysis with snailase is feasible, efficient, and suitable for the industrial production and application.

Inhibitory Effects of Ginsenoside Rb1 on Apoptosis Caused by HSV-1 in Human Glioma Cells

To investigate the inhibitory effects of Ginsenoside Rbl （GRbl） on apoptosis caused by Herpes Simplex Virus-1 （HSV-1） in Human Glioma Cells （U251）, U251 cells were infected by HSV-1 at a multiplicity of infection of 5 and GRbl, GRbl＋HSV-1, HSV-1 and control groups. MTT and cell apoptosis assays were used to detect the inhibitory effects of GRbl on the apoptosis of U251 cells that caused by HSV-1 infection for various concentrations of drug and virus treatments by MTT assay. We found that in the 400 μg/mL GRb 1 and 400 μg/mL GRbl＋HSV-1 groups, MTT values were higher than control group at all times （P〈0.05）. Moreover, the apoptosis rate in the 400 μg/mL GRbl＋HSV-1 group was lower than the HSV-1 group （P〈0. 05）. These results confirmed that, at appropriate concentrations, GRbl could inhibit nerve cell apoptosis in HSV-1 infections.

Ginsenoside Rb1 produces antidepressant-like effects in chronic social defeat stress model of depression through BDNF-TrkB sig⁃naling pathway

OBJECTIVE Ginsenoside Rb1(Rb1),an important bioactive ingredient of Panax ginseng,has potent neuroprotective effects.The objective of the study is to elucidate the impact of Rb1 treatment on chronic social defeat stress(CSDS)-induced depressive-like behaviors and its related mechanism.METHODS AND RE⁃SULTS The daily oral administration of Rb1(35 and 70 mg·kg-1)and imipramine(15 mg·kg-1)for 28 d significantly reversed the social avoidance behavior,anhedonia,and behavioral despair via CSDS exposure,as demonstrated by the consid⁃erable elevation in the time in the zone in social interaction test and consumption of sucrose solu⁃tion in sucrose preference test and decrease of immobility time in forced swim test.Moreover,Rb1 obviously restored the CSDS-induced decrease of BDNF-signaling pathway and hippo⁃campal neurogenesis.Rb1 significantly increased the hippocampal levels of ERK,AKT,and CREB phosphorylation and increased the number of DCX+cells in DG.Importantly,the antidepres⁃sant effects of Rb1 were completely blocked in mice by using K252a(the nonselective tyrosine kinase B inhibitor).CONCLUSION Rb1 exerts promising antidepressant-like effects in mice with CSDS-induced depression,and its effects was facilitated by enhancing the BDNF signaling cas⁃cade and up-regulation of hippocampal neuro⁃genesis.

Ginsenoside Rb1 protects dopaminergic neurons from inflammatory injury induced by intranigral lipopolysaccharide injection

Accumulating studies suggest that neuroinflammation characterized by microglial overactivation plays a pivotal role in the pathogenesis of Parkinson’s disease.As such,inhibition of microglial overactivation might be a promising treatment strategy to delay the onset or slow the progression of Parkinson’s disease.Ginsenoside Rbl,the most active ingredient of ginseng,reportedly exerts neuroprotective effects by suppressing inflammation in vitro.The present study aimed to evaluate the neuroprotective and anti-inflammatory effects of ginsenoside Rbl in a lipopolysaccharide-induced rat Parkinson’s disease model.Rats were divided into four groups.In the control group,sham-operated rats were intraperitoneally administered normal saline for 14 consecutive days.In the ginsenoside Rbl group,ginsenoside Rb1(20 mg/kg)was intraperitoneally injected for 14 consecutive days after sham surgery.In the lipopolysaccharide group,a single dose of lipopolysaccharide was unilaterally microinjected into the rat substantial nigra to establish the Parkinson’s disease model.Lipopolysaccharide-injected rats were treated with normal saline for 14 consecutive days.In the ginsenoside Rbl +lipopolysaccharide group,lipopolysaccharide was unilaterally microinjected into the rat substantial nigra.Subsequently,ginsenoside Rbl was intraperitoneally injected for 14 consecutive days.To investigate the therapeutic effects of ginsenoside Rbl,behavioral tests were performed on day 15 after lipopolysaccharide injection.We found that ginsenoside Rbl treatment remarkably reduced apomorphine-induced rotations in lipopolysaccharide-treated rats compared with the lipopolysaccharide group.To investigate the neurotoxicity of lipopolysaccharide and potential protective effect of ginsenoside Rbl,contents of dopamine and its metabolites in the striatum were measured by high-performance liquid chromatography.Compared with the lipopolysaccharide group,ginsenoside Rbl obviously attenuated the lipopolysaccharide-induced depletion of dopamine and its metabolites in the striatum.To further explore the neuroprotective effect of ginsenoside Rbl against lipopolysaccharide-induced neurotoxicity,immunohistochemistry and western blot assay of tyrosine hydroxylase were performed to evaluate dopaminergic neuron degeneration in the substantial nigra par compacta.The results showed that lipopolysaccharide injection caused a large loss of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra and a significant decrease in overall tyrosine hydroxylase expression.However,ginsenoside Rb1 noticeably reversed these changes.To investigate whether the neuroprotective effect of ginsenoside Rbl was associated with inhibition of lipopolysaccharide-induced microglial activation,we examined expression of the microglia marker Iba-1.Our results confirmed that lipopolysaccharide injection induced a significant increase in Iba-1 expression in the substantia nigra;however,ginsenoside Rbl effectively suppressed lipopolysaccharide-induced microglial overactivation.To elucidate the inhibitory mechanism of ginsenoside Rb1,we examined expression levels of inflammatory mediators(tumor necrosis factor-a,interleukin-1β,inducible nitric oxide synthase,and cyclooxygenase 2)and phosphorylation of nuclear factor kappa B signaling-related proteins(IκB,IKK)in the substantia nigra with enzyme-linked immunosorbent and western blot assays.Our results revealed that compared with the control group,phosphorylation and expression of inflammatory mediators IκB and IKK in the substantia nigra of lipopolysaccharide group rats were significantly increased;whereas,ginsenoside Rbl obviously reduced lipopolysaccharide-induced changes on the lesioned side of the substantial nigra par compacta.These findings confirm that ginsenoside Rbl can inhibit inflammation induced by lipopolysaccharide injection into the substantia nigra and protect dopaminergic neurons,which may be related to its inhibition of the nuclear factor kappa B signaling pathway.This study was approved by the Experimental Animal Ethics Committee of Shandong University of China in April 2016(approval No.KYLL-2016-0148).

Neuroprotective effects of ginsenoside Rb1 on hippocampal neuronal injury and neurite outgrowth

Ginsenoside Rb1 has been reported to exert anti-aging and anti-neurodegenerative effects. In the present study, we investigate whether ginsenoside Rb1 is involved in neurite outgrowth and neuroprotection against damage induced by amyloid beta（25–35） in cultured hippocampal neurons, and explore the underlying mechanisms. Ginsenoside Rb1 significantly increased neurite outgrowth in hippocampal neurons, and increased the expression of phosphorylated-Akt and phosphorylated extracellular signal-regulated kinase 1/2. These effects were abrogated by API-2 and PD98059, inhibitors of the signaling proteins Akt and MEK. Additionally, cultured hippocampal neurons were exposed to amyloid beta（25–35） for 30 minutes; ginsenoside Rb1 prevented apoptosis induced by amyloid beta（25–35）, and this effect was blocked by API-2 and PD98059. Furthermore, ginsenoside Rb1 significantly reversed the reduction in phosphorylated-Akt and phosphorylated extracellular signal-regulated kinase 1/2 levels induced by amyloid beta（25–35）, and API-2 neutralized the effect of ginsenoside Rb1. The present results indicate that ginsenoside Rb1 enhances neurite outgrowth and protects against neurotoxicity induced by amyloid beta（25–35） via a mechanism involving Akt and extracellular signal-regulated kinase 1/2 signaling.

Protective Effects of Ginsenoside Rb1 on Septic Rats and Its Mechanism

This study aims to observe the protective effects of ginsenoside Rbl on liver and lung in rats with septic shock and reveal its mechanism. Rats were randomly divided into three groups： sham, cecal ligation and puncture （CLP）, and CLP with ginsenoside Rb1. Then, the survival rate, arterial blood pressure, TLR4 mRNA, and TNF-α levels were determined. The liver and lung tissues were stained with hematoxylin-eosin （HE）. The overall survival rate of the Rb1 group was significantly higher than that of the CLP group. Mean arterial blood pressure went down in both the CLP and Rb1 groups after CLP, and there was a significant difference both in the sham and Rb1 groups when compared with the CLP group. The Rb1 treatment group had markedly lower TLR4 mRNA expression and TNF-a levels than the CLP group. In the CLP group, pathology showed swelling, degeneration, necrosis, and neutrophii infiltration in the liver and alveolar epithelial cells. However, in the Rb1 group, there was mild degeneration and slight neutrophil infiltration, but no obvious necrosis. Rb1 may improve the survival rate, ameliorate arterial blood pressure, and protect the liver and lung in septic shock rats by downregulating the expression of TLR4 mRNA and inhibiting the production of TNF-α.

Ginsenoside Rg1 protects against ischemia reperfusion-induced neurotoxicity through miR-144/Nrf2/ARE pathway

OBJECTIVE Ginsenoside Rg1(Rg1),a purified compound from Panax ginseng,has been well documented to be effective against ischemia/reperfusion(I/R) neurotoxicity.However,the underlying mechanism is stil obscure.METHODS The anti-I/R effect of Rg1 were investigated in vitro and in vivo,and the dynamics of nuclear accumulation and the transcriptional activity of NF-E2-related factor 2(Nrf2) determined by Western blotting and Dual Luciferase Reporter Assay,respectively.Nrf2 siRNA was employed to investigate Nrf2′s role in the protective effect of Rg1 against I/R.Furthermore,the role of miR-144,which could regulate post-translational Nrf2 levels,was investigated in the anti-I/R effect of Rg1 by injection of AAV-hypoxia-inducible factor miR-144-shRNA in the predicted ischemic penumbra.RESULTS It was found that the anti-I/R effect of Rg1 was related to its anti-oxidative capacity,which is mainly regulated by the Nrf2/antioxidant response element(ARE) pathway.Further study suggested that Rg1 contributes to the enhancement of the Nrf2/ARE pathway,as manifested by increasing the dynamic peak content of Nrf2,which prolonged the maintenance stage,and promoting the expression of ARE-target genes after oxygen glucose deprivation/reperfusion(OGD/R) in PC12 cells.Nrf2-siRNA application significantly reduced these changes.Furthermore,the enhancement of the Nrf2/ARE pathway by Rg1 was independent of disassociation from Keap1;rather it was a result of posttranslational regulations.It was found that Rg1 significantly reduced the expression of miR-144,which down-regulates Nrf2 production by targeting its 3′-untranslated region,after OGD/R.Knockdown of Nrf2 showed no effect on the expression of miR-144,indicating that miR-144 is an upstream regulator of Nrf2.Moreover,direct binding between Nrf2 and miR-144 in the PC12 cells was identified.Application of anti-miR-144 significantly reduced Rg1′s anti-OGD/R capacity.Final y,the role of miR-144 in Rg1′ s anti-I/R effect was tested by inhibiting miR-144 in the predicted ischemic penumbra when hypoxia-inducible-factor was activated.The results showed that loss of miR-144 abolished the anti-I/R effect of Rg1,which included reduced infarct volume,improved neurological scores,attenuated oxidative impairment,as well as activation of the Nrf2/ARE pathway.CONCLUSION Oxidative stress after I/R is alleviated by Rg1 through inhibition of miR-144 activity and subsequent promotion of the Nrf2/ARE pathway at the post-translational level.

Ginsenoside Rb1 Attenuates Isoflurane/surgery-induced Cognitive Dysfunction via Inhibiting Neuroinflammation and Oxidative Stress

Objective Anesthetic isoflurane plus surgery has been reported to induce cognitive impairment. The underlying mechanism and targeted intervention remain largely to be determined. Ginsenoside Rb1 was reported to be neuroprotective. We therefore set out to determine whether ginsenoside Rb1 can attenuate isoflurane/surgery-induced cognitive dysfunction via inhibiting neuroinflammation and oxidative stress. Methods Five-months-old C57BL/6J female mice were treated with 1.4% isoflurane plus abdominal surgery for two hours. Sixty mg/kg ginsenoside Rb1 were given intraperitoneally from 7 days before surgery. Cognition of the mice were assessed by Barnes Maze. Levels of postsynaptic density-95 and synaptophysin in mice hippocampus were measured by Western blot. Levels of reactive oxygen species, tumor necrosis factor-α and interleukin-6 in mice hippocampus were measured by ELISA. Results Here we show for the first time that the ginsenoside Rb1 treatment attenuated the isoflurane/surgery-induced cognitive impairment. Moreover, ginsenoside Rb1 attenuated the isoflurane/surgery-induced synapse dysfunction. Finally, ginsenoside Rb1 mitigated the isoflurane/surgery-induced elevation levels of reactive oxygen species, tumor necrosis factor-α and interleukin-6 in the mice hippocampus. Conclusion These results suggest that ginsenoside Rb1 may attenuate the isoflurane/surgery-induced cognitive impairment by inhibiting neuroinflammation and oxidative stress pending future studies.