姜黄素及其代谢修饰产物对PC12细胞氧化损伤的保护作用

Protective Effects of Curcumin and Its Metabolites on HO-Induced Oxidative Damage in PC12 Cells

为比较姜黄素及其两种主要代谢修饰产物(四氢姜黄素和姜黄素-β-D-葡糖苷酸)对H2O2诱导的大鼠肾上腺嗜铬瘤PC12细胞氧化损伤的保护作用,细胞经上述受试物处理后,采用噻唑蓝法测定细胞存活率,2’,7’-二氯荧光黄双乙酸盐荧光探针测定活性氧自由基(reactive oxygen species,ROS)含量,试剂盒检测细胞内超氧化物歧化酶(superoxide dismutase,SOD)活力和丙二醛(malondialdehyde,MDA)含量,Western Blot测定细胞内抗氧化相关蛋白的表达。结果表明:姜黄素及其代谢产物能够显著降低氧化损伤的PC12细胞内ROS含量和MDA水平,显著提高SOD活力(P<0.05),上调肾脏细胞质和细胞核中Nrf2蛋白表达量,激活下游血红素氧合酶-1和腺嘌呤二核苷酸醌氧化还原酶蛋白表达。总体来看,姜黄素代谢修饰后的产物抗氧化损伤作用弱于姜黄素。实验结果为揭示姜黄素的健康功效机制提供了实验依据。

This study aimed to compare the protective effects of curcumin and its major metabolites tetrahydrocurcumin and curcumin-β-D-glucuronide on H2O2-induced oxidative damage in rat adrenal pheochromocytoma PC12 cells. After the cells were treated with the three compounds separately, the cell viability and reactive oxygen species(ROS) level were determined by thiazolyl blue tetrazolium bromide assay and 2’,7’-dichlorodi-hydrofluorescein diacetate fluorescent probe, respectively. Meanwhile, superoxide dismutase(SOD) and malondialdehyde(MDA) were detected by commercial kits, and the expression of antioxidant proteins was quantified by Western blot. The results showed that curcumin and its metabolites significantly reduced H2O2-stimulated ROS and MDA levels in PC12 cells, increased SOD activity(P < 0.05), up-regulated the expression of Nrf2 protein in the cytoplasm and nucleus of kidney, and activated downstream hemeoxygenase-1 and NADPH quinineoxidoreductase-1 proteins. In general, the curcumin metabolites presented weaker protective effects than curcumin. These results may provide an experimental basis to understand the health-promoting mechanism of curcumin.