| With recent progress in mechanism of cerebral ischemic damage, neuroprotective therapy has been an innovative conception in clinical therapy. The therapeutic effect of flavanoid to ischemic cerebrovascular disease has been proved. Its function is to cleanup the free radical,restrain the lipid peroxidation;to through stimulating its release and restraining its degradation of catechol amine, as well as stimulating the prostacyclin relaxing factor's generation, it is coming true to better adjusting the recirculating system. Moreover, it has the function of reducing the whole blood viscosity, increasing the ductility of red blood cell and white blood cell, and improving the condition of blood circulation. It can increase the flow of oxygen and glucose at the area of ischemia organization, and increase the amount of some certain neurotransmitter, thereby to implement its protective function to tissues.After cerebral vascular occlusion, blood vessel hyperplasia happened in the ischemic region, the scope and the degree of the hyperplasia directly relationship with the improvement of the bloodflow in the penumbra field, and influence the recovery of the nerve cell's physiologic function. The expression of vascular endothelial growth factor is very low in the common tissue of the humans and animals, but can be evoked in the pathological conditions such as the cerebral ischemia. VEGF can increase the proliferation of the endothelial cell, induce the angiogenesis, prevent the disappearance of the capillary vessel and the programmed death of endothelial cell, and stimulate the growth of axon. VEGF has the neuroprotective effect to the ischemic neurons.The Ovateleaf actinidia leaf we picked from Changbai mountain area of our Jilin province distributes widely there. It is one of the special local plants of Changbai mountain area, its fruits are used to strengthening with tonics in folk living. Now the investigation about it is so little, only one piece of document reporting that two species of flavones have been abstracted from ovateleaf actinidia leaf, and the investigation didn't research deeply in aspects of biological activity,clinical pharmacology, and so on. We together with other unit carried out an investigation of relating ovateleaf actinidia leaf's chemical composition andpharmacodynamics. We have extracted 9 species of flavonoid,3 species of flavanoid were first time to be discovered,and now it is in the process of applying patent for new compound. From analyzing the chemcial constitution of the main extraction of total flavonoids from Ovateleaf actinidia leaf, we find that the main structure of flavone in it are extremely the same compared with the ginkgetin from Extract of Ginkgo Biloba Leaf. Further more, the composition of total flavonoids in ovateleaf actinidia leaf far more than in ginkgetin, and it's possible to outweigh in pharmacologic action than ginkgetin's in some aspect. We carried out an animal experiment to confirm its medicine therapeutic effect.Empirical method: eighty healthy Wistar male rats were chosen and randomly divided into A sham operated group, B control group of sodium chloride, C little dosages, D middle dosages, E large dosages. We induced focal cerebral ischemia model in rats by Nagasawa occlusion methods of middle cerebral artery. The rats of C,D,E groups were given different dosages of the extractive flavone of Ovateleaf actinidia leaf by intraperitoneal injection 30 min before the operation and 2 hours after the operation. We measure thevolume of the infarction focus by TTC dyeing and image analysis system, and observe the histopathology and ultrastructural pathology by transmission electron microscope. Make use of the method of immunohistochemistry to observe the expression of vascular endothelial growth factor in brain tissue of rat of each group.Experimental result: The infarction volume of the groups which given the drug were smaller (P<0.05), and the change of the ultramicrostructure were also lighter compared with the control group of sodium chloride. The expression of vascular endothelial growth factor is very low in the common brain tissue ,but can be evoked in the pathological conditions of the cerebral ischemia. The groups which given the drug compare with the control group of sodium chloride, the expression of VEGF are more obviously,and in experiment dose extent, it express more and more following the raise of the medicine dose .Experimental conclusion:1,successfully reproduced the pattern of ischemia in the arteria cerebri media of rats, it is fairly the ideal pattern in researching focal cerebral ischemia. 2,Confirmed that the expression of vascular endothelial growth factor are increase innumber after focal cerebral ischemia. It can provide us a theory base for researching the mechanism of nerves protection after cerebral ischemia. 3,Compared with the giving medicine grope and the control group, we find out that in the process of focal cerebral ischemia , the extractive flavone of Ovateleaf actinidia leaf can lighten the infarction volume, improve the change of brain tissue pathology ultrastructural, induce the expression of VEGF, exert its neuroprotective effect, and help to recovering the nerves function.
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