Study On Antithrombotic Effect And Long-term Toxicity Of Folium Ginkgo

Objective:To prepare ginkgo biloba crude extract, and evaluate its antithrombotic effect and long-term toxicity.Method:â‘ he ethanol percolation method was used to prepare Ginkgo biloba leaf crude extract.â‘¡The rat inferior vena cava thrombosis model was established to study the anti-thrombosis effect of the Ginkgo biloba crude extract.â‘¢ccording to the method of long-term toxicity test in Chinese Guidance Principle of New Drug Research and the result of that there were no toxic reaction and death when oral Ginkgo biloba crude extract exceeded 5g/kg in acute toxicity test of mouse, the dosage exceeding 30 and 120 times of clinical treatment was used to the rats this experiment.The rat in normal control group had only taken distilled water.The rats used for long-term toxicity were grouped first by gender, then divided into the following groups(30rats/group)following the principle of minimum weight differences:control group, low dose group, high-dose group. Low and high doses were 1.03g/kg and 4.12g/kg, respectively. They were 30 and 120 times of the doses of patients of 60kg, while the control group received the same volume of normal saline. The administration was lasted for 24 weeks. In the administration period, the comprehensive observation was carried out, and the dead animals were dissected for death reasons on time. After the last administration, the conventional and biochemical indicators of blood were determined. After autopsy, the main organs of the animals were collected for the organ indexes calculation and histopathological examination.Results:Compared with the control group, Ginkgo biloba crude extract at high and low dose group had a antithrombotic effects, the thrombus wet weight and dry weight at the same time (p<0.01) while the the rats at high and low dose showed that the wet weight inhibition of thrombus were 47.6% and 23.6%, respectively, and the dry weight of thrombus inhibition rates were 50% and 9.4%, respectively. It was more obvious in high dose group.In the long-term toxicity test administration process, the high and low dose group animals showed dull fur, reduced food intake significantly, and the other general signs were normal. After 24 weeks of administration, the body weight of the high and low dose group animals were significantly reduced. Organ coefficient of different dose group had no obvious changes. Hematological indexes and blood chemistry indexes showed a number of very significant changes occur. Among them, the percentage of neutrophil, monocyte percentage, the percentage of eosinophils, basophils percentage of red blood cell count, hemoglobin, red blood cell volume and platelet count were decreased significantly (p<0.01), and lymphocyte percentage and mean platelet volumes were increased significantly (p<0.01). The urea, creatinine, triglycerides, total cholesterol, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total protein, albumin and acid phosphate kinase muscle levels were significantly decreased (p<0.01). The prothrombin time was significantly longer (p<0.01). The blood potassium level was decreased, blood sodium level was increased (p<0.01), while serum chloride level of change was not significant (p>0.05).Conclusions:Ginkgo biloba extract has significant anti-thrombotic effect. If given for a long-term and at large doses, it can significantly change the number of hematological indexes and blood parameters, but obvious pathological change had not been discovered.