目的 探讨京尼平及其衍生物对硝普钠诱导的PC12细胞损伤的保护作用及其作用机制。方法 通过62.5~1 000 μmol/L硝普钠处理PC12细胞24 h建立细胞损伤模型，造模前2 h给予京尼平衍生物预处理，采用噻唑蓝比色法（MTT）考察京尼平衍生物对PC12细胞存活率的影响。Hoechst染色后观察细胞形态，以DCFH-DA探针和丙二醛（MDA）检测试剂盒分别检测PC12细胞内ROS、MDA水平，RT-PCR法检测PC12细胞抗氧化应激基因水平。结果 与对照组比较，硝普钠能剂量相关性地降低PC12细胞的存活，在750 μmol/L时具有统计学差异，而10 μmol/L 1R-异丙基-6，7-二氢京尼平（化合物4）、1S-异丙基-6，7-二氢京尼平（化合物5）能够明显增加硝普钠诱导PC12细胞损伤后的细胞存活率（P<0.05、0.01）。Hoechst染色形态学证实化合物4、5能够明显减少PC12细胞的凋亡。硝普钠诱导PC12细胞内氧化应激水平，化合物4、5能有效地降低ROS、MDA水平，并促进抗氧化酶基因GCLC、GPX、CAT mRNA表达，但对HO-1、MnSOD基因表达水平无明显影响。结论 京尼平衍生物可以抑制硝普钠诱导的PC12细胞损伤和细胞内氧化应激水平，其作用机制可能是通过影响抗氧化酶GCLC、CAT、GPX mRNA表达水平而实现。

Objective To study the protective effect of genipin derivatives against sodium nitroprusside-induced PC12 cells damage and its mechanisms. Methods PC12 cells were treated with 62.5-1 000 μmol/L sodium nitroprusside for 24 h to evaluate damage, then pre-treated by genipin derivatives for 2 h. Effect of genipin derivatives on cell survival rate of sodium nitroprusside-induced PC12 cells was evaluated by MTT assay. Morphological changes of PC12 cells were observed by Hoechst 33258 nuclear and DCFH-DA staining. ROS and MDA production levels were measured using commercial assay kits. Meantime, the expression of anti-oxidant enzyme gene was determined by RT-PCR. Results Compared with the control group, cell survival rate of sodium nitroprusside-induced PC12 cells decreased in a dose-dependent manner at the dose of 750 μmol/L. Compounds 4 and 5 with concentration of 10 μmol/L significantly decreased the cell apoptosis rate induced by sodium nitroprusside (P<0.05 and 0.01). Hoechst staining showed that compounds 4 and 5 could significantly decrease the apoptosis of PC12 cells. The level of oxidative stress in PC12 cells were induced by sodium nitroprusside. Compounds 4 and 5 could effectively reduce ROS and MDA levels, and promote the mRNA expression of anti-oxidant enzyme genes GCLC, GPX, and CAT, but it showed no significant effect on mRNA levels of HO-1 and MnSOD. Conclusion Genipin derivatives can inhibit level of oxidative stress damage in PC12 cells induced by sodium nitroprusside, which may be related to the change of mRNA expression of anti-oxidant enzyme GCLC, CAT, GPX gene.

国家自然科学基金资助项目（81560662）；江西省卫生计生委中医药科研课题（2015A050）江西中医药大学博士启动基金项目（2014BS012）