绞股蓝总皂苷及其不同提取物对实验性高血压大鼠的降压作用

目的 研究绞股蓝总皂苷和绞股蓝不同提取物对大鼠血压的影响。方法 将大鼠分为9组,除空白对照组外,高血压模型组、绞股蓝总皂苷对照组、绞股蓝总皂苷干预组(绞股蓝总皂苷180 mg/kg、 360 mg/kg、720 mg/kg,低、中、高剂量组)、总提取物组、乙酸乙酯提取物组和正丁醇提取物组的大鼠均被喂养高脂高糖饲料和饮用糖盐水(糖4%、盐1%)和果糖水(6%)。绞股蓝总皂苷对照组、绞股蓝总皂苷干预组、总提取物组、乙酸乙酯提取物组和正丁醇提取物组的大鼠均给予相应剂量的药物灌胃。给药8周后处死大鼠,测定大鼠血清中一氧化氮(NO)、内皮素(ET)和血管紧张素Ⅱ(AngⅡ)含量。结果 与空白对照组相比,高糖高脂饮食能明显使大鼠血压的增高[收缩压增高(34.9±9.8)%,舒张压增高(17.9±8.5)%],差异有统计学意义(P<0.05)。与高血压模型组相比,绞股蓝总皂苷对照组收缩压降低(39.7±6.9)%、舒张压降低(36.7±7.3)%,血压显著性降低(P<0.05)。与空白对照组相比,绞股蓝总皂苷对照组、乙酸乙酯提取物组、正丁醇提取物组收缩压、舒张压相差不大(P>0.0...     

绞股蓝皂甙抗谷氨酸诱导的氧化性神经毒性

目的：探讨绞股蓝皂甙(gypenoside，GP)对谷氨酸(glutamate，Glu)介导的氧化性神经毒性的拮抗作用。方法：体外培养胎鼠大脑皮层神经细胞，建立Glu氧化性损伤模型，用MTT法测定细胞活力，透射电镜观察Glu所致的神经细胞死亡方式，流式细胞术分析细胞凋亡率。结果：GP以时间依赖性方式明显拮抗谷氨酸介导的氧化性神经毒性，于Glu损伤前达到最佳保护效果，Glu氧化性毒性导致神经细胞发生凋亡兼具坏死特征的死亡，Glu损伤组细胞凋亡率(21．63％)明显高于正常对照组(0．09％)及GP保护组(8．94％)。结论：GP可明显拮抗Glu介导的氧化性神经毒性。     

绞股蓝总皂甙对体外培养人口腔鳞癌颈淋巴结转移癌细胞抑制作用的研究

采用MTT法和电镜观察，研究了绞股蓝总皂甙（GP）对人体口腔鳞癌颈淋巴结转移癌细胞的抑制作用。结果表明，GP可抑制转移癌细胞的增殖，并对癌细胞内线粒体和粗面内质网有损伤作用。提示GP可用于口腔转移癌的治疗。     

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 andGP-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-αand NF-κB in the rat liver was analyzed using immunohistochemistry.The expression of proliferatoractivated receptor gamma(PPARγ)and cytochrome P450(CYP450)1A1 m RNA was determined by quantitative RTPCR.RESULTS:GP treatments at oral doses of 200,400,and800 mg/kg per day significantly decreased the levels of serum AST and ALT(P0.05,P0.01),especially at the dose of 800 mg/kg per day.To a similar extent,GP at800 mg/kg per day reduced the levels of BG(4.19±0.47,P0.01),TG(80.08±10.05,P0.01),TC(134.38±16.39,P0.01)and serum insulin(42.01±5.04,P0.01).The expression of TNF-αand NF-κB measured by immunohistochemistry was significantly reduced by GPs in a dose-dependent manner,and the expression of PPARγand CYP4501A1 m RNA,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 dosedependent manner.CONCLUSION:This study suggests that GPs have a protective effect against T2DM-NAFLD by down-regulating the expression of TNF-αand NF-κB proteins,and PPARγand CYP4501A1 m RNAs.     

绞股蓝总苷对大鼠局灶性脑缺血损伤的保护作用

目的探讨绞股蓝总苷对局灶性脑缺血损伤的保护作用及相关机制。方法用线栓法制备大鼠大脑中动脉脑缺血模型,治疗7d后,对大鼠神经行为进行评分,并测定大鼠脑组织中MDA含量、GSH-Px及SOD活性。结果绞股蓝总苷能明显改善大鼠的行为障碍,提高GSH-Px、SOD酶活力,降低MDA含量。结论绞股蓝总苷对大鼠脑缺血损伤具有保护作用,其机制可能与提高抗氧化酶活性、抗自由基损伤等作用有关。     

绞股蓝总皂苷对家兔离体十二指肠平滑肌收缩活动的影响

目的：观察绞股蓝总皂苷对家兔离体十二指肠平滑肌收缩活动的影响。方法：采用常规十二指肠平滑肌标本离体灌流的实验方法,加入不同浓度的绞股蓝总皂苷（0.01%～1.00%）,通过Medlab生物信号采集处理系统分别记录加药前后十二指肠平滑肌的收缩曲线。结果：不同浓度的绞股蓝总皂苷均可以显著降低十二指肠平滑肌的收缩幅度,与绞股蓝总皂苷的浓度呈剂量依赖性关系。结论：绞股蓝总皂苷可以抑制家兔离体十二指肠平滑肌的自律性收缩活动。     

绞股蓝总苷对人脐内皮细胞损伤的保护作用

目的研究绞股蓝总苷（GPs）对胆固醇所致人脐静脉内皮细胞（hVECs）损伤的保护作用及机制。方法以体外培养的hVECs-12为研究对象,设正常对照组、溶媒组（二甲基亚砜）、胆固醇组（以50mg/L胆固醇处理48h）、3种浓度绞股蓝总苷（1、10、100μg/ml）组（按剂量在培养基中加入绞股蓝总苷预处理1h后再加入50mg/L的胆固醇处理48h）。分别用比色法、硝酸酶还原法及ELISA法检测细胞培液中乳酸脱氢酶（LDH）活性、一氧化氮（NO）浓度、单核细胞趋化蛋白-1（MCP-1）浓度;以DCFH-DA为荧光探针,流式细胞术检测细胞内活性氧水平;免疫细胞化学染色方法检测细胞内核因子-κBp65（NF-κBp65）核移位阳性细胞数。结果与正常对照组比较,胆固醇组各指标差异均有统计学意义（P〈0.01）;与胆固醇组比较,GPs可减少细胞培液中LDH活性、MCP-1浓度、并能增加NO浓度（P〈0.01）、可降低细胞内ROS的水平（P〈0.01）;GPs能抑制NF-κB核移位（P〈0.01）,且随浓度升高有递减趋势。结论绞股蓝总苷对胆固醇所致的人脐静脉内皮细胞损伤具有保护作用,机制可能与减少细胞内ROS的生成,从而抑制NF-κB活化有关。     

绞股蓝总皂甙对兔实验性动脉粥样硬化斑块形成的影响

为了探讨绞股蓝总皂甙防止动脉粥样硬化的作用及其机制．在新西兰兔食饵性动脉粥样硬化模型上，观察了绞股蓝总皂甙治疗性给药对主动脉壁粥样硬化斑块形成及脂质过氧化的影响。发现绞股蓝总皂甙（120mg／d）治疗四周能减少主动脉壁斑块形成．苏丹IV染色及形态计量学分析显示绞股蓝总皂甙治疗组的斑块面积较之高脂组减少了37％；主动脉壁脂质过氧化程度也明显减轻，丙二醛含量仅为高脂组的67％。此外，还观察到绞股蓝总皂甙在减少主动脉壁斑块形成和脂质过氧化的同时，还能保护血管壁释放或合成一氧化氮的能力，并防止因长期高胆固醇血症引起的主动脉壁Ca2 超载。绞股蓝总皂甙的作用与抗氧化剂维生素E相似。     

The inhibitory effect of Gynostemma pentaphyllum on MCP-1 and type I procollagen expression in rat hepatic stellate cells

Aim of the study

Gynostemma pentaphyllum is a popular folk medicine that has been used for treatment of hepatitis in Asia. Our previous study demonstrates that Gynostemma pentaphyllum n-butanol extract inhibits the onset and improves the recovery of CCl₄-induced liver fibrogenesis in rats and inhibits PDGF-induced rat hepatic stellate cells (HSCs) proliferation. In this study, the effect of Gynostemma pentaphyllum extract on cytokines and type I procollagen expression was analyzed.

Materials and methods

Rat HSCs were treated with PDGF, Gynostemma pentaphyllum n-butanol extract, RP-18-Gyp fraction, rapamycin or vehicle. Rat cytokine antibody array chip or ELISA kit was used for cytokines detection. Intracellular protein expression was detected by Western blotting, mRNA expression was analyzed by RT-PCR.

Results

RP-18-Gyp fraction is the more purified gypenosides fraction from Gynostemma pentaphyllum n-butanol extract. In cell proliferation, the inhibitory effect of 200 μg/ml RP-18-Gyp fraction is similar to 500 μg/ml Gynostemma pentaphyllum n-butanol extract. Furthermore, both of them have the ability of decreasing monocyte chemoattractant protein-1 (MCP-1) mRNA expression and protein release and inhibiting type I procollagen protein expression.

Conclusions

Both of Gynostemma pentaphyllum n-butanol extract and its more purified RP-18-Gyp fraction have the biological activities in the inhibition of cell proliferation, MCP-1 release and type I procollagen expression in rat HSCs. These data could provide the evidence to support for the traditional use of Gynostemma pentaphyllum in hepatitis.     

人参皂甙等清除超氧阴离子自由基的研究

筛选自由基清除剂常用黄嘌呤氧化酶氧化黄嘌呤产生O_2~-·,但此体系中黄嘌呤氧化酶易被药物抑制,致使结果分不清是由于药物清除O_2·~-的作用还是药物抑制黄嘌呤氧化酶而