葛根素对AD大鼠脑内Aβ_(1-40)和Bax表达的影响

Effect of puerarin on the expression of Aβ_(1-40) and Bax in brain of AD rats induced by Aβ_(25-35)

目的研究杏仁核注射β-淀粉样肽(Aβ25-35)所致阿尔茨海默病(AD)模型大鼠脑内Aβ1-40、Bax的表达变化,以及葛根素(Pue)的影响。方法将30只SD大鼠随机分为假手术组、AD模型组和Pue治疗组,以Aβ25-35右侧杏仁核注射制备大鼠AD模型,用Y-型迷宫检测大鼠学习记忆能力,用免疫组织化学方法检测大脑皮层与海马组织Aβ1-40和Bax的表达。结果假手术组脑内有Aβ1-40、Bax的少量表达,两者均以皮层内为多,海马组织内少;AD模型组大鼠皮层和海马组织Aβ1-40与Bax的表达增加,较假手术组大鼠有显著性差异,P<0.01;Pue能改善AD模型组大鼠的学习记忆能力,Pue治疗组大鼠皮层和海马组织Aβ1-40、Bax表达减少,与AD模型组比较有显著性差异,P<0.05。结论Pue可能通过下调脑组织Aβ1-40和Bax表达,抑制β-淀粉样肽的神经毒性,减轻脑皮层和海马神经元凋亡,具有神经保护及抗痴呆作用。

Objective To investigate the effect of puerarin on the expression of Aβ1-40 and Bax in brain of AD rats induced by Aβ25-35. Methods Thirty SD rats were divided into sham-operated group, AD model group and Puerarin treatment group, at random. AD rat models were established by the injection of Aβ25-35 into the right amygdala. Learning and memory abilities of rats were tested through Y-maze. The expressions of protein Aβ1-40 and Bax in cortex and hippocampus were detected by immunohistochemistry. Results There were small number of positive cells of Aβ1-40 and Bax in sham-operated group; the number of the both in cortex was larger than that in hippocampus. The expression of Aβ1-40 and Bax in cortex and hippocampus was increased in AD model group, which was significantly different compared with sham-operated group （P〈0.01）. Puerarin significantly alleviated the spatial learning and memory impairment induced by Aβ25-35. The expression of Aβ1-40 and Bax protein in cortex and hippocampus of AD rats was decreased remarkably by puerarin, which was significantly different compared with AD model group （P〈0.05）. Conclusion Puerarin can attenuate the neurotoxicity of β-amyloid peptide through down-regulating the expression of Aβ1-40 and Bax in rat brain. Puerarin may restrain neuron apoptosis in cortex and hippocampus of AD rats and contribute to neuroprotection and anti-dementia.