大黄及其提取物对大鼠脑缺血损伤的保护作用

目的:从自由基损伤和钙超载方面探讨大黄及其提取物抗脑缺血损伤的作用机制。方法:结扎SD大鼠双侧颈总动脉48h,观察脑组织病理改变,测定脑含水量、Ca~(2+)含量、Ca~(2+)-ATP-ase活性,测定脑组织和血清中SOD活性和MDA含量。结果:与假手术组比较,模型组脑含水量增加,病理损伤严重,脑组织中Ca~(2+)含量增高、Ca~(2+)-ATP-ase活性降低,脑组织和血清MDA含量的增高和SOD活性的降低显著。与模型组比较,尼莫地平组和其它用药组脑组织病理损伤减轻、含水量降低;尼莫地平组、大黄组、大黄部位4组脑组织Ca~(2+)、MDA降低和Ca~(2+)-ATP-ase、SOD活性增高,大黄部位1组Ca~(2+)-ATP-ase、SOD活性增高和Ca~(2+)含量降低,大黄部位3组SOD活性增高和MDA、Ca~(2+)含量下降;尼莫地平组、大黄组、大黄部位3组、大黄部位4组血清SOD活性的增高和MDA含量降低显著,大黄部位1组MDA降低显著。结论:大黄及四个不同部位可改善脑缺血损伤,其作用机制可能与其拮抗自由基损伤和减轻钙超载有关。

Protective Effect of Rhubarb and Its Extraction on Cerebral Ischemia in Rats

Objective :To study the effects of rhubarb and its four different parts on the cerebral ischemia in rats in free radical ad calcium overload. Method ? Bilateral common carotid arteries were deligated to duplicate incomplete cerebral ischemic model. Taking speciments after ischemia 48 hours. The changes of the brain pathologic, brain water ratio, the content of brain Ca2+ and Ca2+-ATP-ase activities, brain and serum SOD and MDA were measured. Results: Compared with the sham-operated group, the cerebral water ratio was higher and the change of cerebral pathomorphology was more obvious, the content of brain Ca2+ increased and Ca2+ -ATP-ase activities decreased, cerebral and serum SOD activity was lower and MDA content was higher in the model group. Cerebral pathomorphology and cerebral water ratio was alleviated in the ND's, the R's, the R1's, the R 2's, the R3's, the R4's than those of model group. The content of cerebral Ca2+ and MDA decreased, the activity of Ca2 + -ATP-ase and SOD increased in the ND's, the R's, the R4's;the content of cerebral Ca2+ decreased, the activity of Ca2+-ATP-ase and SOD increased in the Rl's; the content of cerebral Ca and MDA decreased, the activity of SOD increased in the R3's. The activity of serum SOD increased and the level of MDA decreased in the ND's, the R's, the R3's, the R4's; the level of serum MDA decreased in the Rl's. Conclusion : Rhubarb and its four different parts, especially the R3 and the R4, could alleviate cerebral ischemia injury, the effect machenism might related to inhibite the injury induced by free radical and calcium overload.