二苯乙烯苷对高胆固醇血症致β-淀粉样肽增高大鼠模型的影响

目的　观察何首乌提取物二苯乙烯苷 (2, 3, 5, 4′ tetrhydroxystilbene 2 O β D glucoside,TSG)对高胆固醇血症致β 淀粉样肽(β amyloid,Aβ)增高大鼠模型脑海马区Aβ、血脂及血液流变学的影响,分析二苯乙烯苷抗老年性痴呆(AlzheimersDisease,AD)的作用机制。方法　以高胆固醇饲料(含 1%胆固醇, 0 3%胆酸盐 )喂饲大鼠 10wk,建立高胆固醇血症大鼠模型。用TSG连续灌胃 10wk,以免疫组织化学和放射免疫分析法测定脑海马区Aβ水平;以全自动生化分析法测定血清胆固醇 (CHO)、低密度脂蛋白胆固醇(LDL C)含量;而且测定了全血粘度及红细胞聚集性。结果高胆固醇饲料喂饲 10wk后,模型大鼠脑海马区可见Aβ蛋白表达及Aβ含量明显增加;血清CHO、LDL C明显升高;全血粘度及红细胞聚集性升高。TSG能降低脑海马区Aβ含量,抑制Aβ蛋白表达,减少血清CHO和LDL C含量,降低全血粘度及红细胞聚集性。结论　TSG能够减少脑Aβ的生成,降低血清胆固醇、低密度脂蛋白胆固醇水平,改善血液流变学;具有治疗AD的应用前景。

Effects of tetrahydroxystilbene-glucoside on rat model of β-amyloid increase induced by hypercholesterol

Aim To investigate the effects of 2,3,5,4′-tetra hy droxystilbene -2-O-β-D-glucoside (TSG) on brain β-amyloid (Aβ)content, blood fat,and hemorheology in rat model induced by hypercholesterol.Me thods The animal model of hypercholesterolemia was induced by feeding h igh cholesterol forage containing 1% cholesterol and 0.3% cholic acid for 10 w eeks. TSG was given orally at doses of 30, 60 and 120 mg·kg -1 body wt/da y for 10 weeks also. The content of β-amyloid was measured by immunohistochemi stry and radioimmunoassay methods,the serum cholesterol and low density lipopro tein (LDL-C) were measured by automatic biochemistry analytical methods, and s ome indices of hemorheology were also observed.Results The cont ent of Aβ in hippocampus of rat model was increased after feeding high choleste rol forage for 10 weeks,and the serum cholesterol and low density lipoprotein l evel were obviously elevated as well, TSG shortened the content of Aβ in hippo campus,the serum cholesterol and low density lipoprotein level obviously. The i ndices of hemorheology showed that blood viscosity (ηb, high and low shear rat e) and RBC adhesion index (AI) were increased in rats. TSG decreased blood visco sity (ηb, high and low shear rate) and lowed RBC adhesion index (AI) in rat mo del.Conclusion TSG possesses obvious action of reducing the con tent of Aβ in hippocampus, decreasing serum cholesterol and low density lipopr otein, promoting blood circulation and removing blood stasis.These actions may be related to the therapeutic mechanisms of AD.