山茱萸环烯醚萜苷对穹隆海马伞切断大鼠海马区神经元存活和细胞凋亡调控因子的影响

目的探讨山茱萸环烯醚萜苷(cornel iridoid glycoside,CIG)对脑损伤大鼠海马区神经元存活的影响及其作用机制。方法 成年SD大鼠行穹隆海马伞切断(fimbria-fornix transection,FFT)手术,造模后CIG灌胃给药28d,采用尼氏染色方法光镜下观察海马CA1区和齿状回存活神经元的变化;采用Western blotting法检测海马区细胞凋亡调控因子Bcl-2、Bax和细胞色素C的蛋白表达变化。结果 尼氏染色结果显示,FFT模型大鼠海马CA1区和齿状回存活神经元明显减少;CIG(20、60、180mg.kg-1)灌胃给药能够增加模型大鼠海马区存活神经元的数量。Western blotting结果显示,FFT模型大鼠海马区Bcl-2表达减少,Bax和细胞色素C表达增高;CIG能够增强模型大鼠海马区Bcl-2表达,抑制Bax和细胞色素C的表达,避免凋亡信号进一步激活。结论 CIG能够减少FFT模型大鼠海马区神经元死亡数量,其作用机制可能与上调细胞凋亡抑制因子、下调细胞凋亡促进因子有关。

Effects of Cornel Iridoid Glycoside on Hippocampal Neuron Survival and Apoptosis-regulating Factors in Fimbria-fornix Transected Rats

Objective To investigate the effects of cornel iridoid glycoside(CIG) on hippocampal neuron survival and its mechanism after brain injury in rats.
Methods Rat model of mechanical brain injury was induced by fimbria-fornix transection(FFT). CIG was intragastrically administered for 28 days after the operation. Nissl's staining was used to evaluate neuron survival in hippocampal CA1 and dentate gyrus. Protein expression of apoptosis regulating factors(including Bcl-2, Bax and cytochrome C) in the hippocampus of rats was detected by Western blotting.
Results Nissl staining showed a significant decrease in survived neurons in hippocampal CA1 and dentate gyrus of FFT model rats; the administration of CIG(20, 60 and 180 mg·kg-1) significantly increased the number of neuronal survival, compared with the model rats. The protein expression of Bcl-2 was decreased, and the expression of Bax and cytochrome C was increased in hippocampus of FFT model rats; CIG significantly increased Bcl-2 expression and decreased the expression of Bax and cytochrome C, compared with the model rats.
Conclusion CIG markedly increased hippocampal neuronal survival in FFT model rats, and its mechanism may be related to the upregulation of apoptosis-inhibiting factors and downregulation of apoptosis-promoting factors.