Study On Effect Of Antiplatelet Aggregation And Antithrombosis Of Total Flavonoids Of Bauhinia Aurea Levl

Flavonoids existed widely in plant kingdom and exhibited many bioactivities. Especially,it provided with many functions for treating cardiovascular disease,such as strengthening cardiotropic effect,against ischemic muscular atrophy,vasodilating activities,lowering blood pressure,antiarrhythmic effect,falling blood fat and anti-atherosclerosis effect.Flavonoids could effectively inhibit platelet aggregation and thrombosis.Bauhinia aurea Levl was the flower of Cersis chinensis Bunge.It possessed effects of antipyretic and treating thrombocytopenic purpura..The study report about extraction of total flavonoids from Bauhinia aurea Levl and its applications of platelet aggregation and thrombosis were not found at present.So now,extraction and purification of total flavonoids from Bauhinia aurea Levl and its effects to platelet aggregation and thrombosis was studying.Its objective was to afford experimental data for application of Bauhinia aurea Levl.The main experimental information was as follows:1.Extraction of total flavonoids of Bauhinia aurea LevlTotal flavonoids of Bauhinia aurea Levl were respectively extracted by 4 kinds of water extraction,water extraction and alcohol precipitation,ethyl alcohol extraction,acid and ethyl alcohol extraction.Extraction effect was found preferably for acid and ethyl alcohol extraction,ethyl alcohol extraction,and ethyl alcohol extraction for total flavonoids was confirmed by considering acid and alkali.4 factors and 3 levels of extraction temperature,ethyl alcohol concentration,extraction time and solvent dosage were choosed.The parameters of total flavonoids of Bauhinia aurea Levl were performed and confirmed by L₉(3⁴)orthogonal test,and the conditions were 15 volume of 55%ethyl alcohol,2h hot water refluence at 100℃for 3 times.Effect degree of 4 factors to extraction was as follows:ethyl alcohol concentration＞extraction temperature＞extraction time＞solvent dosage.The experiment was repeatedly carry through optimized process,and average extraction rate of crude flavonoids was 7.32%. 2.Purification and identification of total flavonoids of Bauhinia aurea LevlCrude flavonoids of Bauhinia aurea Levl was purified by polyamide resin chromatography,it was washed orderly with distillation water,and 10%,30%,70%of ethyl alcohol.The experiment result was found that total flavonoids of Bauhinia aurea Levl were mainly concentrated in the washing part of 70%ethyl alcohol,and extraction rate of purified total flavonoids was 2.20%.Total flavonoids of Bauhinia aurea Levl was identified and analysed by chromogenic reaction,thin layer chromatography,HPLC, UV-VIS and IR.Chromogenic reaction showed that extract of Bauhinia aurea Levl composed of flavonoid structure of 5-OH or 2-OH.3 kinds of flavone glycoside of rutin, quercetin and kaempferol or their analogue were found in extract of Bauhinia aurea Levl by qualitative identification of thin layer chromatography,HPLC,UV-VIS and IR. Quantitative analysis result of UV-VIS showed that content of total flavone glycoside in purified flavonoids of Bauhinia aurea Levl was 24.30%,and content of total flavonoid was 0.5346%.3.Effect of platelet aggregation by total flavonoids of Bauhinia aurea LevlEffect of platelet aggregation by total flavonoids of Bauhinia aurea Levl was observed by experiment of clotting and platelet aggregation in vitro,determination of contents of TXB₂ and 6-Keto-PGF_1α.It was found in clotting experiment that mid and high dose of total flavonoids of Bauhinia aurea Levl could prolong clotting time of mice. Experiment of platelet aggregation in vitro in rats showed that mid and high dose of total flavonoids of Bauhinia aurea Levl could obviously inhibit platelet aggregation in rats tempting by ADP.With the increasing of each group concentration of total flavonoids of Bauhinia aurea Levl,contents of TXB₂ had decreased(P＜0.05～P＜0.01), and contents of 6-Keto-PGF_1αhad elevated(P＜0.05～P＜0.01).The results showed that total flavonoids of Bauhinia aurea Levl inhibited AA metabolism or TXA₂ synthesize with decreasing contents of TXB₂ and elevating contents of 6-Keto-PGF_1α.It suggested that could inhibite platelet aggregation by hastening of PGI₂ synthesize in endothelium blood cell.4.Effect of thrombosis by total flavonoids of Bauhinia aurea LevlEffect of thrombosis by total flavonoids of Bauhinia aurea Levl was observed by experiment of arteriovenous thrombosis in rats and thrombosis in mouse.Experiment of arteriovenous thrombosis in rats showed that thrombus wet weight of group of total flavonoids of Bauhinia aurea Levl decreased with the increasing of dose,it could probably inhibit arteriovenous thrombosis in rats by decreasing of platelet adhesion and inhibiting of platelet aggregation.It was found in thrombosis experiment of collagen-adrenalin in mouse that mid and high dose of total flavonoids of Bauhinia aurea Levl could obviously inhibit thrombosis and protect mice hemiplegia.