拟人参皂苷元对大鼠局灶性脑缺血损伤的保护作用

Protective effects of ocotillol on focal cerebral ischemic injury in rats

目的观察拟人参皂苷元对大鼠局灶性脑缺血损伤的保护作用,并探讨其作用机制。方法缺血前给予拟人参皂苷元1.25、2.5、5、10、20mg.kg-1,灌胃7d,末次给药1h后制备大鼠大脑中动脉栓塞局灶性缺血模型(MCAO),12h后测定大鼠脑梗死面积并进行脑组织病理观察,制备脑组织匀浆测定超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。结果大鼠脑缺血12h后,脑组织出现大面积梗死灶,且MDA含量增加,SOD活力降低。拟人参皂苷元(5mg.kg-1)能减小脑梗死面积,改善缺血损伤所致的脑组织病理形态学改变,并且降低缺血脑组织中MDA含量,升高SOD的活性。结论拟人参皂苷元对大鼠局灶性脑缺血损伤具有明显保护作用,该作用可能与抑制脂质过氧化、提高抗氧化酶活性有关。

Aim To observe the protective effects of ocotillol on focal cerebral ischemia in rats and to explore its possible mechanism. Methods Two hundred and fourty male Wistar rats were randomly divided into eight groups ： sham group, ischemia group, nimodipine group and five ocotillol groups, to which ocotillol was administered at dose of 1.25,2. 5,5,10 and 20 mg· kg^-1, respectively. Middle cerebral artery occlusion （MCAO） was used to induce focal cerebral ischemia model. After 12 hours ischemia,infarction area of brain was assessed in brain slices stained with 2% solution of 2, 3, 5-triphenyl tetrazolium chloride （TTC）. HE stain was used to observe the pathological changes in hippocampus region of ischemia rats. Superoxide dis-mustase （ SOD ） activity and malondialdehyde （ MDA ） content in homogenate of ischemic brain tissue were determined by spectrophotometric assay. Results Compared with ischemia group, ocotillol at a dose of 5 mg · kg^-1 could reduce the percentage of infarction area in the cerebral hemisphere, ameliorate the pathological changes in hippocampus CA1 area, increase SOD activity and decrease MDA content in ischemic brain tissue. Conclusions Ocotillol has protective effects on focal cerebral ischemic injury, and its mechanism may be related to the antioxidant action.