葛根素对脑缺血诱导神经细胞凋亡的保护作用

Effects of Puerarin on Neuronal Apoptosis Induced by Cerebral Ischemia in Rats

目的探讨葛根素(puerarin,Pur)对脑缺血诱导神经细胞凋亡和凋亡蛋白抑制剂XIAP表达的影响。方法SD大鼠大脑中动脉栓塞(MCAO)的同时ip50,100mg.kg-1Pur,MCAO50min后再灌注24h,用TTC染色法、Annexin-V和PI双荧光标记结合流式细胞检测法、半定量RT-PCR等技术分别检测大鼠脑水肿、梗死体积、细胞凋亡和坏死率、caspase-3活性、XIAPmRNA表达。结果Pur(100mg.kg-1)明显缓解缺血引起的脑水肿和神经行为障碍(P<0.05);减少脑梗死体积,以皮层尤其显著(P<0.01)。Pur(100mg.kg-1)还显著降低背外侧皮层的细胞凋亡和坏死率,抑制caspase-3活性,逆转缺血诱导的XIAPmRNA表达下调(P<0.05,P<0.01)。结论Pur通过调节神经细胞XIAPmRNA表达,抑制细胞凋亡而保护缺血性脑损伤。

OBJECTIVE To investigate the effects of puerarin（Pur）on the apoptosis and regulation of XIAP expression induced by cerebral ischemia. METHODS Male SD rats were treated with 50 min middle cerebral artery occlusion（MCAO）followed by reperfusion for 24 h. Put（50, 100 mg·kg^- 1, ip）was administrated at the onset of MCAO. Twenty-four hours after reperfusion, neurological deficits were assessed in Put-and vehicle-treated rats. The infarct volume and edema ratios were evaluated from TIC stained brain slices. Apoptosis and necrosis were measured using flow cytometric analysis of Annexin-V and PI labeling cells. Furthermore, the expression of the X-chromosome-linked inhibitor of apoptosis protein（XIAP） was analyzed by RT-PCR. RESULTS Put（ 100 mg·kg^-1 ）obviously attenuated ischemia-induced edema and neurological deficits, and markedly reduced infarction（ P 〈 0.05, P 〈 0.01 ）. The percentages of apoptosis and necrosis in dorsolateral cortex were significantly decreased（ P 〈 0.01 and P 〈 0.05）following treatment with Put（ 100 mg·kg^- 1 ） in MCAO rats. Furthermore, caspase-3 activity, as a biochemical marker of apoptosis, was significantly inhibited, and XIAP mRNA was significantly up-regulated by Put（ 100 mg·kg^-1 ）in the dorsolateral cortex of MCAO rats. CONCLUTION The neuroprotection of puerarin against cerebral ischemia is associated with the regulation of XIAP and the inhibition of apoptosis.