蒺藜皂苷对PC12细胞凋亡的保护作用及机制

Protective effect and its molecular mechanism of gross saponin tribulus terrestris on apoptosis of PC12 cells

目的探讨蒺藜皂苷(gross saponin tribulus terrestris,GSTT)对过氧化氢(H2O2)诱导的大鼠肾上腺嗜铬细胞瘤细胞(pheochromocytoma cells,PC12)凋亡的保护作用及其机制。方法PC12细胞分为对照组、模型组及蒺藜皂苷高(GSTT1)、低(GSTT2)剂量组。用H2O2刺激PC12细胞使其发生凋亡,MTT法检测PC12细胞活性,倒置相差显微镜观察细胞形态,Hoechst 33258荧光核染色,流式细胞仪检测PC12细胞亚二倍体峰比率及Western blot方法检测与凋亡相关蛋白Bcl-2、Bax。结果与模型组比较蒺藜皂苷组随着剂量的增加PC12细胞存活率提高(P<0.01),凋亡细胞减少,凋亡比率下降(P<0.01),Bcl-2表达增加(P<0.05),而Bax的表达降低(P<0.05)。结论蒺藜皂苷可抑制H2O2诱导的PC12细胞凋亡,其机制可能与抑制线粒体途径的细胞凋亡及影响凋亡相关蛋白的表达有关。

Aim To investigate the protective effect of gross saponin tribulus terrestris（GSTT） on the apoptosis of PC12 cells was induced by H2O2 and its mechanism. Methods Apoptosis of PC12 cells was induced by H2O2 at the concentration of 300 μmol · L^-1. The cell activity was determined by MTT. Cells were observed by inverted phase contrast microscope. Hochest33258 staining was detected by fluorescence microscope. The subdiploid peaks showing cell apoptosis rate was detected by flow cytometry. Protein of Bcl-2 and Bax was detected by Western blot. Results Corn-pared with model group,the survival rate of PC12 cells increased （P 〈 0.01 ）, apoptosis cells and the apoptotic rate and protein expression of Bax decreased （P 〈 0. 01）,and protein expression of Bcl-2 increased with the rise of GSTT dose （ P 〈 0. 05 ）. Conclusion GSTT could inhibit the apoptosis of PC12 cells induced by H2O2 which might be correlated with the inhibition of apoptosis in the path of mitochondrion and influence the expression of the apoptosis protein.