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.

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 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.

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.

A New Saponin Transformed from Ginsenoside Rh_1 by Bacillus subtilis

A novel saponin was isolated from the transformed products of ginsenoside Rh1 by Bacillus subtilis. It's structure was determined to be 3-O-β-D-glucopyranosyl-6-O-β-D-gluco- pyranosyl-20 (S)-protopanaxatriol on the basis of the spectral data.

人参皂苷Rg_1和Rh_1抗肿瘤作用的研究

目的 :研究人参皂苷 Rh1及其前体 Rg1的整体及离体抗肿瘤作用。方法 :整体实验 4种小鼠移植性肿瘤 :小鼠宫颈癌 - 1 4( U14 )、艾氏腹水癌 ( EAC)、肉瘤 - 1 80 ( S180 )和肝癌腹水型 ( Hep A)腋部皮下接种 ,于接种 1 0 d内 ,每天给药 1次 ,计算各给药组肿瘤抑制率。离体抗肿瘤实验用 3种瘤株 :A375 - S2、T98G 和 He La。结果 :人参皂苷 Rg1( 2 0 0 mg·kg-1,灌胃 )和 Rh1( 4 0和2 0 mg· kg-1,腹腔注射 )对 U14 均具有明显的抑制作用 ( P<0 .0 1 ) ;人参皂苷 Rh1在较高剂量( 4 0 mg·kg-1)时 ,对 EAC也有明显抑制作用 ( P<0 .0 1 )。但人参皂苷 Rg1和 Rh1对 S180 和 Hep A无抗肿瘤作用。离体实验证明 ,Rg1对 He La细胞的增殖有明显的抑制作用 ,Rh1高剂量组( 1 0 0 mg· L-1)对 3种肿瘤细胞均有明显抑制作用。结论 :人参皂苷 Rh1较其前体

人参皂苷Rg_1及其肠内菌代谢产物Rh_1对小鼠免疫细胞功能的影响

目的 初探人参皂苷Rg1 及其肠内菌代谢产物Rh1 对正常小鼠免疫功能的影响。方法 用Rh1 与Rg1 分别处理脾T细胞 ,B细胞及腹腔巨噬细胞 (Mφ) ;MTT比色法测T和B细胞增殖能力 ;中性红比色法测Mφ的吞噬功能 ;Griess法测Mφ释放NO的水平。 结果 Rh1 能促进脾细胞增殖、下调ConA诱导的T细胞增殖 ;Rh1 与Rg1 对LPS诱导的B细胞增殖均无明显作用 ;Rg1 和Rh1 能提高Mφ的吞噬能力和促进NO的释放。 结论 Rg1 及其代谢产物Rh1 可共同作用于T细胞和Mφ而产生免疫调节作用。

人参皂甙Rb_1、Rg_1、Re和Rh_1对HeLa细胞的影响

本研究应用细胞化学及ＭＴＴ法，测定人宫颈癌细胞（ＨｅＬａ）在人参皂甙Ｒｂ１、Ｒｇ１、Ｒｅ、Ｒｈ１作用３～５ｄ后，细胞增殖和细胞化学含量的变化。结果表明，四种人参单体皂甙与人参根总皂甙作用相似，可以抑制ＨｅＬａ细胞的增殖，降低ＨｅＬａ细胞内多糖（ＰＡＳ）、葡萄糖６磷酸脱氢酶（Ｇ６ＰＤＨ）、葡萄糖６磷酸酶（Ｇ６Ｐａｓｅ）、乳酸脱氢酶（ＬＤＨ）和琥珀酸脱氢酶（ＳＤＨ）的含量。本文提示，不同的人参单体皂甙均可以降低癌细胞的增殖和代谢活性，但Ｒｅ、Ｒｈ１的作用更显著。

人参皂苷Rh_2对MSB-1细胞的增殖抑制作用及其机理

以不同质量浓度的人参皂苷Rh2与马立克氏病肿瘤细胞系MSB-1细胞共同作用,利用改良MTT法测定了人参皂苷Rh2对MSB-l细胞的增殖抑制作用,并通过流式细胞术、荧光检测和电镜形态学观察等方法探讨其抑制机理。结果显示:人参皂苷Rh2对MSB-l细胞的增殖存在抑制作用,并呈剂量依赖性,人参皂苷Rh2与MSB-1细胞培养72 h后的半数抑制质量浓度为0.65 mg/L;流式细胞术测定表明,人参皂苷Rh2可阻滞MSB-1细胞于S期;荧光检测和透射电镜观察表明,人参皂苷Rh2可以诱导部分MSB-1细胞发生凋亡。

人参皂苷Rg1通过Sestrin2保护心肌细胞的作用

目的研究人参皂苷Rg1(G-Rg1)对抗心肌缺血再灌注损伤中Sestrin2的作用及相关机制。方法体外培养大鼠H9c2心肌细胞,按实验要求随机分5组,分别为对照组,缺氧复氧组,G-Rg1组,缺氧诱导因子-1α(Hypoxia Inducible Factor-1,HIF-1,HIF-1α)抑制剂组,Sestrin2 siRNA干扰组。流式细胞术检测各组心肌细胞内活性氧簇(reactive oxygen species,ROS)含量。蛋白质免疫印迹法检测HIF-1α、Sestrin2、蛋白激酶R样内质网激酶(protein kinase R-like ER kinase,PERK)、活化转录因子6(the activating transcription factor6,ATF-6)和跨膜蛋白激酶1(inositol requiring enzyme 1,IRE-1)蛋白表达。免疫荧光法检测Sestrin2、HIF-1α、IRE-1蛋白表达。结果与对照组相比,缺氧复氧组细胞内ROS水平、HIF-1α、Sestrin2、ATF-6、PERK、IRE-1蛋白表达水平明显升高(P<0.05);与缺氧复氧组相比,G-Rg1组细胞内ROS水平明显降低(P<0.05),HIF-1α、Sestrin2、ATF-6、PERK、IRE-1蛋白表达水平明显升高(P<0.05);与G-Rg1组比较,HIF-1α抑制剂组心肌细胞内ROS水平升高,Sestrin2蛋白表达明显下调(P<0.05);与G-Rg1组比较,siRNA干扰组心肌细胞内ROS水平升高,IRE-1表达明显升高(P<0.05)。结论G-Rg1通过上调Sestrin2表达,保护缺氧复氧心肌细胞,并维持内质网应激平衡稳态。

人参皂苷Rg1注射液联合肌苷片和维生素B_(1)治疗原发性视网膜色素变性

目的:探讨人参皂苷Rg1注射剂联合肌苷片和维生素B_(1)对原发性视网膜色素变性的血清脑源性神经营养因子(BDNF)、垂体腺苷酸环化酶激活多肽(PACAP)影响及临床疗效。方法:纳入2019-08/2022-03河北北方学院附属第二医院眼科收治的50例100眼原发性视网膜色素变性患者作为研究对象,按随机数字表分为研究组和对照组,各50眼。对照组患者给予肌苷片和维生素B_(1)治疗,研究组患者给予人参皂苷Rg1注射剂联合肌苷片和维生素B_(1)治疗。比较治疗前后两组血清BDNF和PACAP表达、视网膜电图、光谱域光学相干断层扫描(SD-OCT)检查黄斑中心凹为圆点直径1mm范围视网膜厚度(RT)、视野平均缺失(MD)及临床疗效及安全性指标。结果:治疗前,两组MD比较无差异(t=1.670,P=0.098)。治疗后,研究组MD显著低于对照组(t=3.628,P<0.01);治疗前,两组黄斑中心凹为圆点直径1mm范围RT比较无差异(t=0.108,P=0.914)。治疗后,研究组黄斑中心凹为圆点直径1mm范围RT显著高于对照组(t=6.125,P<0.01);治疗前,两组各项视网膜电图暗适应的结果比较无差异(均P>0.05)。治疗后,研究组各项暗视网膜电图暗适应的结果改善均显著优于对照组(均P<0.01)。治疗前,两组各项视网膜电图明适应的结果比较无差异(均P>0.05)。治疗后,研究组各项视网膜电图明适应的结果改善显著优于对照组(均P<0.01)。治疗前,两组BDNF、PACAP比较无差异(均P>0.05);治疗后,研究组BDNF、PACAP高于对照组(均P<0.01)。治疗后,两组均未见任何的不良反应。结论:原发性视网膜色素变性患者采用人参皂苷治疗可通过调节BDNF和PACAP的表达,改善患者视网膜功能,促进病情转归,且安全性高。

人参皂苷Rh_(2)在卵巢颗粒细胞炎性反应中的作用及作用机制网络药理学与分子生物学研究

目的探讨西洋参中人参皂苷Rh(2简称Rh_(2))在脂多糖(LPS)致人卵巢颗粒细胞瘤细胞系KGN细胞炎性反应中的作用及作用机制。方法通过网络药理学方法筛选西洋参治疗多囊卵巢综合征(PCOS)的潜在活性成分及靶点。以200 ng/mL LPS作用KGN细胞6 h诱导炎性反应,采用酶联免疫吸附(ELISA)法测定KGN细胞中炎性因子白细胞介素1β(IL-1β)和肿瘤坏死因子-α(TNF-α)的水平,采用2',7'-二氯双氢荧光素双乙酸酯(DCFH-DA)染色法测定活性氧(ROS)的水平;40µmol/L Rh_(2)作用KGN细胞24 h后,采用免疫印迹(Western blot)法测定哺乳动物雷帕霉素靶蛋白(mTOR)在LPS诱导的KGN细胞中的表达水平。结果网络药理学分析结果显示,共筛选出西洋参的主要化学成分11个、潜在靶点144个、治疗PCOS的靶点13个,其中Rh_(2)与下游靶基因mTOR是西洋参抗PCOS的关键活性成分及潜在作用靶点。分子生物学研究结果显示,Rh_(2)能抑制LPS导致的KGN细胞中ROS和mTOR表达水平的升高,下调IL-1β和TNF-α的表达;低表达(50 nmol/L)mTOR能促进Rh_(2)缓解LPS导致的KGN细胞炎性反应,过表达(3µg)mTOR能逆转此现象。结论Rh_(2)通过调控mTOR的表达水平参与LPS导致的卵巢颗粒细胞炎性反应。

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.

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.

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

To investigate the inhibitory effects of Ginsenoside Rb1 (GRb1) 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 GRb1, GRb1+HSV-1, HSV-1 and control groups. MTT and cell apoptosis assays were used to detect the inhibitory effects of GRb1 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 GRb1 and 400 μg/mL GRb1+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 GRb1+HSV-1 group was lower than the HSV-1 group (P<0. 05). These results confirmed that, at appropriate concentrations, GRb1 could inhibit nerve cell apoptosis in HSV-1 infections.