人参皂甙Rb1对ATP诱导大鼠海马脑片毒性损伤的影响

The effect of ginsenoside Rb1 on ATP induced toxicity in rat hippocampal slices

目的:研究人参皂甙Rb1对ATP诱导大鼠海马脑片毒性损伤的影响及其作用机制。方法:采用SD大鼠离体海马脑片模型,随机分为正常对照组、人参皂甙Rb1对照组、ATP损伤组、人参皂甙Rb1(20μmol/L、40μmol/L、60μmol/L)组、亮蓝G(BBG)组、亮蓝G+人参皂甙Rb1组、2'-3'-O-(4-苯甲酰-苯甲酰)腺苷三磷酸三乙烷胺盐(Bz ATP)组和Bz ATP+人参皂甙Rb1组。测定脑片孵育液中乳酸脱氢酶(LDH)释放率,免疫组化测定海马CA1区和齿状回神经型一氧化氮合酶(n NOS)表达,Western blot测定海马磷酸化c-Jun氨基末端激酶(p-JNK1/2)蛋白表达。结果:人参皂甙Rb1(40μmol/L、60μmol/L)组可明显降低ATP诱导的LDH释放,人参皂甙Rb1(60μmol/L)亦降低海马p-JNK1/2以及CA1区和齿状回n NOS的表达,人参皂甙Rb1(60μmol/L)对由P2X7受体激动剂Bz ATP诱导的LDH释放和n NOS、p-JNK1/2表达亦有明显抑制作用。P2X7受体抑制剂亮蓝G可明显减低ATP诱导的LDH释放,但BBG联合应用人参皂甙Rb1(60μmol/L)并未增强人参皂甙Rb1的保护作用。结论:人参皂甙Rb1可明显抑制ATP诱导的大鼠海马脑片毒性损伤,其作用机制与抑制P2X7受体,进而减少nNOS和p-JNK1/2的表达有关。

Aim： To investigate the effect of ginsenoside Rb1 on ATP induced toxicity in rat hippocampal slices and its mechanism. Methods： SD rat hippocampal slices in vitro were randomly divided into the control group,Rb1＋ control group,ATP group,Rb1（ 20μmol/L,40μmol/L and60μmol/L） groups,BBG group,BBG ＋ Rb1 group,BzA TP group and BzA TP ＋ Rb1 group. The cell injury was tested by LDH release rate in incubation fluid of hippocampal slices. Expressions of nNOS in hippocampal CA1 and dentate gyrus regions were measured by immunohistochemical assay,and expressions of p-JNK1/2 were measured by western blot. Results： Ginsenoside Rb1（ 40 and 60μmol/L） significantly decreased LDH release rate. Ginsenoside Rb1（ 60μmol/L） also decreased expressions of nN OS and p-JNK1/2 induced by ATP. The similar protective effect of ginsenoside Rb1（ 60μmol/L） was observed on the P2X7 receptor agonist BzA TP induced toxicity. We also found that the P2X7 receptor antagonist BBG significantly decreased LDH release rate,but the effect of ginsenoside Rb1（ 60μmol/L） in combination with BBG was not increased. Conclusion： Ginsenoside Rb1 can reduce ATP induced toxicity and the mechanism is related to the inhibition of P2X7 receptor and reductions of nN OS and p-JNK1/2.