石菖蒲-远志药对不同组分对阿尔茨海默病模型大鼠海马Tau蛋白及其Ser396位点磷酸化的影响

Effect of Different Components of Acorus tatarinowii and Polygala tenuifolia on p-Ser396 and Tau-5 Expression in the Hippocampus of Rats with Alzheimer's Disease

目的探讨石菖蒲-远志药对不同组分(挥发油、水提物)对阿尔茨海默病(AD)模型大鼠海马磷酸化Tau蛋白Ser396位点和Tau-5的影响。方法 SD雄性大鼠,随机分为8组,即正常对照组,模型对照组,石菖蒲-远志挥发油小、中、大剂量组,石菖蒲-远志水提物小、中、大剂量组。用D-半乳糖制作亚急性衰老模型,造模成功后治疗组大鼠分别给予石菖蒲-远志不同组分0.6,1.2,1.8 g·kg-1(生药用量)灌胃,正常对照组和模型对照组分别0.9%氯化钠溶液灌胃。给药28 d后,用免疫印迹和免疫组化法检测各组大鼠海马磷酸化Tau蛋白Ser396位点和Tau-5水平。结果模型对照组与正常对照组比较,Tau蛋白Ser396位点磷酸化水平明显上升(P<0.01);模型对照组,石菖蒲-远志挥发油小、中、大剂量组,石菖蒲-远志水提物小、中、大剂量组Tau蛋白Ser396相对表达分别为3.83±0.10,3.35±0.01,3.11±0.01,2.75±0.03,2.93±0.01,2.55±0.07,2.23±0.08;石菖蒲-远志药对两种组分均可使AD模型大鼠海马内Tau蛋白Ser396位点发生不同程度去磷酸化,且呈剂量依赖性,水提物组分略优于挥发油组分,尤其大剂量组明显(P<0.01),但Tau-5无明显变化(P>0.05)。结论石菖蒲-远志药对能促进AD模型大鼠海马内Tau蛋白Ser396位点去磷酸化,尤以水提物组分效果明显。

Objective To investigate the different components of Acorus tatarinowii and Polygala tenuifolia（volatile oil, aqueous extract）on the expression of phosphorylated Tau protein at site Ser396 and Tau-5 in the hippocampus of rats with Alzheimer′s disease（AD）. Methods Male Sprague Dawley rats were randomly divided into 8 groups：normal control group, model control group,low-,middle-,and high-dose groups of volatile oil of Acorus tatarinowii and Polygala tenuifolia,and low-, middle-,and high-dose groups of aqueous extract of Acorus tatarinowii and Polygala tenuifolia. The subacute aging model was established by intraperitoneal injection of D-galactose（ D-gal）. Rats were given different components of Acorus tatarinowii and Polygala tenuifolia（crude drug dosage,0.6,1.2,1.8 g·kg^-1 ）in experimental groups,and 0.9% sodium chloride solution in normal control group and model control group,by gavage for 28 days.The levels of phosphorylated Tau protein at site Ser396 and Tau-5 were detected in hippocampal tissues by Western blotting and immunohistochemistry. Results The levels of phosphorylated Tau protein at site Ser396 were significantly enhanced in the model control group,as compared with those in normal control group （P〈0.01）.The relative expression levels of Tau protein Ser396 were 3.83±0.10,3.35±0.01,3.11±0.01,2.75±0.03,2.93±0.01,2.55± 0.07,and 2.23±0.08 in model control group,low-,middle-,and high-dose groups of volatile oil of Acorus tatarinowii and Polygala tenuifolia,and low-,middle-,high-dose groups of aqueous extract of Acorus tatarinowii and Polygala tenuifolia,respectively.Two components of Acorus tatarinowii and Polygala tenuifolia could dephosphorylate Tau protein Ser396 to vary degrees in a dose-dependent manner.The aqueous extract component was slightly better than the volatile oil component,especially in the high-dose group（P〈0.01）.But Tau-5 did not change significantly after treatment with Acorus tatarinowii and Polygala tenuifolia（P〉0.05）. Conclusion Acorus tatarinowii and Polygala tenuifolia could promote the dephosphorylation of Ser396 site of Tau protein in the hippocampus of AD rats,with the aqueous extract component having better effects.