槲皮素对脑出血大鼠神经细胞凋亡与Bcl-2、Bax蛋白表达的作用研究

Effects of Quercetin on Neuronal Apoptosis and Bcl-2 and Bax Protein Expressions in Rats after Intracerebral Hemorrhage

目的通过观察大鼠脑出血后神经细胞凋亡与Bcl-2、Bax蛋白表达的动态变化及槲皮素的干预作用,探讨槲皮素可能的神经保护作用及机制。方法以雄性健康SD大鼠通过自体血注入法制备大鼠脑出血模型,并随机分为假手术组、脑出血模型组、槲皮素低剂量组、槲皮素高剂量组,共4组,每组30只;槲皮素低剂量组和槲皮素高剂量组分别给予槲皮素10、50 mg/(kg·d)腹腔内注射,假手术组和脑出血模型组给予同等体积生理盐水腹腔内注射,每日1次,连续7 d;各组大鼠分别在术后第6小时、1天、2天、3天、7天通过前肢放置试验评分法评估神经功能缺损,采用TUNEL法检测血肿周围神经细胞凋亡,采用Western blot法检测血肿周围Bcl-2和Bax蛋白的表达情况。结果与模型组比较,槲皮素低剂量组在脑出血后第3天、7天及槲皮素高剂量组在第2天、3天、7天的前肢放置试验评分和Bcl-2蛋白表达均明显增加(P<0.01);与模型组比较,槲皮素低剂量组在第3天、7天及槲皮素高剂量组在第1天、2天、3天、7天的神经细胞凋亡率和Bax蛋白表达均明显降低(P<0.01)。结论槲皮素能减轻脑出血后神经功能损伤,其机制可能与上调Bcl-2蛋白表达,下调Bax蛋白表达,从而减少神经细胞凋亡有关。

Objective To investigate the possible neuroprotective mechanism of quercetin by observing the intervention effect of quercetin and the dynamic change of expressions of Bcl-2 and Bax and neural cell apoptosis in rats with intracerebral hemorrhage.Methods The models of intracerebral hemorrhage were prepared by autologous blood injection in male healthy SD rats and randomly divided into 4 groups,including a sham operation group,an intracerebral hemorrhage model group,a quercetin low-dose group,and a quercetin high-dose group,with 30 rats in each group.The quercetin low-dose group and the quercetin high-dose group were given quercetin 10 mg/(kg·d)and 50 mg/(kg·d)intraperitoneal injection,respectively.The sham operation group and the intracerebral hemorrhage model group were given the same volume of normal saline once a day for 7 consecutive days.Forelimb placing test score was designed to assess the nerve functional at 6 h,1 d,2 d,3 d and7 d respectively.The apoptosis index of peripheral tissues was analyzed by TUNEL staining,and the expressions of Bcl-2 and Bax were detected by the method of Western blot.Results Compared with the model group,the quercetin low-dose group and the quercetin high-dose group,respectively in 3 d,7 d and 2 d,3 d,7 d after intracerebral hemorrhage had significantly increased the forelimbs placement test scores and the Bcl-2 protein expressions(P<0.01);compared with the model group,the quercetin low-dose group and the quercetin high-dose group respectively in 3 d,7 d and 1 d,2 d,3 d,7 d,had significantly decreased apoptosis rate of nerve cells and the Bax proteins expressions(P<0.01).Conclusion Quercetin can relieve the neurologic impairment after cerebral hemorrhage,and its mechanism may be related to the up-regulation of Bcl-2 protein expressions and down-regulation of Bax protein expressions,thus reducing the apoptosis of nerve cells.