银杏叶提取物(EGb)对大鼠局部脑缺血及颈动脉血栓形成的保护作用

应用大鼠大脑中动脉梗塞和血栓形成导致缺血性脑卒中的实验模型,观察银杏叶提取物(EGb)对脑缺血面积和由缺血造成的行为障碍的影响。结果表明预防或治疗性iv大剂量EGb(200mg·kg^-1)均能显著减少脑缺血面积,明显改善大鼠脑缺血造成的行为障碍,其预防作用似优于治疗作用。预防性iv小剂量EGb(100mg·kg^-1)也能明显减少血栓形成性脑缺血面积,改善梗塞和血栓形成性脑缺血所致的行为障碍,与阳性对照药尿激酶和尼莫地平作用相同。实验还发现EGb有抑制大鼠电刺激颈总动脉的血栓形成的作用,且其对抗血栓形成强度具剂量依赖性。提示EGb对缺血性脑卒中和血栓形成有预防和治疗作用。

PROTECTIVE EFFECTS OF GINKGO BILOBA EXTRACT ON FOCAL CEREBRAL ISCHEMIA AND THROMBOGENESIS OF CAROTID ARTERY IN RATS

Rat focal cerebral ischemia induced by occlusion and thrombogenesis of middle cerebral artery(MCAO) was used as experimental model to study the effects of extract of Ginkgo biloba (EGb) and the positive control drugs were urokinase and nimodipine on cerebral infarct size and neurological deficits. The results showed that cerebral ischemia and neurological deficits appeared in rat focal cerebral ischemic models, and the degree was of cerebral ischemia larger in occlusion model than in thrombogenesis model. The cerebral infarct size was significantly smaller and neurological deficits greatly improved at large dose of EGb(200 mg.kg-1, i.v.), the preventive effect appeared to be better than the treatment effect. The positive control drugs urokinase and nimodipine were also shown to distinctly decrease the cerebral infarct size and improve the neurological deficits in the models. Small dose of EGb(100 mg.kg-1, i.v.) was found to decrease the cerebral infarct size of thrombogenesis model, and improve neurological deficits of both thrombogenesis and occlusion model. EGb was also shown to inhibit the thrombogensis of rat common carotid artery stimulated by electrical current in dose-dependent manner. This experiment indicates that EGb might have beneficial effects on prevention and treatment of ischemic stroke and thrombogenesis.