雌马酚对PC12细胞缺氧/复氧损伤的保护作用及其机制

目的探讨雌马酚对PC12细胞缺氧/复氧损伤的保护作用及机制。方法以PC12细胞为研究对象，构建体外神经元缺氧/ 复氧损伤模型，用雌马酚进行干预。MTT法检测细胞活力，比色法测定细胞培养上清液中乳酸脱氢酶（LDH）活性和丙二醛（MDA）含量，免疫细胞化学法检测活性氧（ROS）含量，Western blotting 检测缺氧/复氧损伤的PC12 细胞内NADPH氧化酶2 （gp91phox）和磷酸化Src（p-Src）激酶的表达。结果雌马酚可有效减轻缺氧/复氧引起的PC12细胞损伤，降低缺氧/复氧损伤细胞培养上清液中LDH的活性和MDA的含量，明显抑制ROS的生成及gp91phox和p-Src的表达。结论雌马酚通过抑制p-Src激酶和gp91phox表达，减少ROS生成，从而对PC12细胞缺氧/复氧损伤产生保护作用。

Equol protects PC12 neuronal cells against hypoxia/reoxygenation injury in vitro by reducing reactive oxygen species production

Objective Both of gp91phox (an isoform of nicotinamide adenine dinucleotide phosphate-reduced oxidases) and Src (a non-receptor protein tyrosine kinase) play a prominent role in mediating hypoxia/reoxygenation injury of neurons. The present study was designed to investigate the neuroprotective effect of equol, a predominant active metabolite of daidzein, against hypoxia/reoxygenation injury in rat pheochromocytoma cell line (PC12) and explore the underlying mechanisms. Methods PC12 cells exposed to hypoxia/reoxygenation injury were examined for reactive oxygen species (ROS) using dihydroethidium and 2’, 7’-dichlorofluorescein diacetate and analyzed for changes in lactate dehydrogenase (LDH) activity and malondialdehyde (MDA) content. The expression levels of gp91phox and phosphorylated Src-Tyr416 (p-Src) were measured using Western blotting. Results Equol dose-dependently restored the cell viability and decreased LDH activity and MDA content in culture medium of PC12 cells exposed to hypoxia/reoxygenation. Pretreatment of the cells with 10-5 and 10-6 mol/L equol inhibited hypoxia/ reoxygenation-induced increase of ROS. PC12 cells treated with equol prior to hypoxia/reoxygenation injury showed significant enhancement of the protein levels of gp91phox and p-Src. Conclusion Equol confers neuroprotection against hypoxia/ reoxygenation injury in PC12 cells by inhibiting the generation of ROS very likely as a result of down-regulation of gp91phox and inhibition of Src phosphorylation.