Abstract: Objective: To investigate the preventive effects of Polygala on sciatic nerve-related neurons injury of diabetic peripheral neuropathy (DPN) rats. Methods: The Wistar rats were randomly divided into 3 groups: blank control group, DPN model group and Polygala prevention group (n=12). The rats in DPN model group and Polygala prevention group were made streptozotocin induced diabetes model. Then the rats in Polygala prevention group were lavaged with Polygala (2.7g/kg/d) for 6 weeks. The DPN rats' model was established with SNCV˂30m/s as the standard. The immunohistochemical staining was used to detect the number of Bcl-2 and Bax positive cells in sciatic nerve-related dorsal root ganglia; Western Blot to detect Bcl-2 and Bax expression in dorsal root ganglia and TUNEL to detect apoptotic index of neurons in dorsal root ganglia. Results: Compared with blank control group, the Bcl-2 immuno-positive cells and Bcl-2 expression in dorsal root ganglia of DPN rats decreased obviously (P˂0.01); while the Bax immuno-positive cells, Bax expression and apoptotic index in dorsal root ganglia increased obviously (P˂0.01). Compared with DPN model group, the Bcl-2 immuno-positive cells and Bcl-2 expression in dorsal root ganglia of rats in Polygala prevention group increased obviously (P˂0.01); while the Bax immuno-positive cells, Bax expression and apoptotic index in dorsal root ganglia of rats in Polygala prevention group decreased obviously (P˂0.01). Conclusions: Polygala can inhibit neurons apoptosis in dorsal root ganglia of DPN rats by upregulating Bcl-2 expression and downregulating Bax expression, so has preventive effects on sciatic nerve-related neurons injury.

Key words: Polygala, Diabetes, Diabetic peripheral neuropathy (DPN), Sciatic nerve, Dorsal root ganglia, Neuron, Apoptosis

摘要： 目的:观察远志对糖尿病周围神经病变（DPN）大鼠坐骨神经相关神经元胞体损伤的预防保护作用。方法:Wistar大鼠随机分为3组(n=12)：空白对照组,DPN模型组及远志预防组。DPN模型组和远志预防组大鼠建立链脲佐菌素致糖尿病模型后,远志预防组大鼠给予远志（2.7g/kg/d）灌胃6周。以大鼠尾部感觉神经传导速度（SNCV）<30m/s为标准建立DPN大鼠模型。采用免疫组织化学染色法检测坐骨神经对应背根节神经元Bcl-2、Bax阳性细胞数,免疫印迹法检测背根节Bcl-2、Bax蛋白的表达,TUNEL法检测背根节神经元的凋亡指数。结果:与空白对照组比较,DPN模型组大鼠背根节Bcl-2阳性细胞数明显减少、Bcl-2的表达明显降低,Bax阳性细胞数明显增多、Bax的表达和凋亡指数明显升高（P<0.01）。与DPN模型组比较,远志预防组大鼠背根节Bcl-2阳性细胞数明显增多、Bcl-2的表达明显升高,Bax阳性细胞数明显减少、Bax的表达和凋亡指数明显降低（P<0.01）。结论:远志可通过上调DPN大鼠背根节神经元胞体Bcl-2的表达,减少Bax的表达,抑制背根节神经元凋亡,预防DPN大鼠背根节神经元胞体损伤。

关键词: 远志, 糖尿病, 糖尿病周围神经病变（DPN）, 坐骨神经, 背根神经节, 神经元, 凋亡