小檗碱对大鼠脑缺血再灌注损伤脑组织Bcl-2、Bax表达及凋亡活性影响

Effect of berberine on expression and apoptosis of Bcl-2 and Bax in cerebral ischemia reperfusion in rats

目的:观察小檗碱对大鼠脑缺血-再灌注损伤后神经保护作用及Bcl-2、Bax表达的影响,探讨小檗碱在脑缺血-再灌注损伤中的抗凋亡作用及机制。方法:线栓法建立大鼠脑缺血再灌注损伤模型,缺血再灌注模型大鼠随机分为模型组、小檗碱低剂量组、小檗碱高剂量组、假手术组,脑缺血2h再灌注24h;分别在再灌注后3h和24h进行神经行为评分,并在再灌注24h后断头取脑。采用连续切片观察组织形态学改变,免疫组织化学技术检测脑组织中Bcl-2、Bax表达的部位及数量。结果:小檗碱组神经功能评分明显低于模型组,且大鼠脑梗死体积较模型组明显缩小,小檗碱高剂量组及低剂量组调高Bcl-2阳性细胞数增多、Bax阳性细胞数减少,Bcl-2/bax的表达比例增加(P<0.05);大鼠额顶部皮质神经元凋亡数目与模型组比较差异有统计学意义(P<0.05)。小檗碱高剂量组大鼠额顶部皮质Bcl-2、Bax阳性细胞数,皮质神经元凋亡数目与低剂量组比较差异有统计学意义(P<0.05)。结论:小檗碱能明显减轻脑缺血再灌注损伤所致的行为障碍,缩小梗死体积,可能通过上调抑凋亡Bcl-2表达、抑制Bax表达,减少细胞凋亡发挥脑保护作用。

Objective To investigate the mechanism and anti-apoptosis effects of berberine on ischemic reperfusion cerebral injury by observing the neuroprotective effects of berberine and the expressions of Bcl-2 and Bax after cerebral ischemia reperfusion injury in rats.Methods The model of cerebral ischemia-reperfusion injury was established by middle cerebral artery occlusion.The rats were divided into four groups,model control group,sham group,small-dose berberine group and large-dose berberine group.All the rats were reperfused for 24 hours after cerebral ischemia for 2 hours.The score of neurological behavior was evaluated at the 3rd and 24th hours after reperfusion.The rats were put to death after 24-hour reperfusion.The histomorphologic changes were observed with serial section technique.The positive neurons of Bcl-2,Bax and the histological changes were observed with immunohistochemical method.Results The neurological function score was significantly lower and cerebral infarct volume was significantly smaller in berberine group than that in model group.Bcl-2 increased,Bax immunoreactive cells decreased （P0.05）,and Bcl-2/bax expression increased in the proportion（P0.05） in large-dose berberine group and small-dose berberine group.There was significant difference in the number of apoptotic neurons in frontal and parietal cortex of rats between berberine group and model group（P0.05）.There were significant differences in Bcl-2,Bax immunoreactive cells and the number of apoptotic cortical neurons in frontal and parietal cortex between large-dose berberine group and small-dose berberine group（P0.05）.Conclusion Berberine can reduce the score of neurological behavior caused by cerebral ischemia-reperfusion and greatly reduce the infarction volume.Berberine plays a role in brain protection by upregulating the expression of Bcl-2 and Bax.