| Flemingia philippinensis is the root of bean plant Flemingia philippinensis (Merr.et Rolfe) with the characteristics of sweet, sour and gentle action. It can remove humidness, improve circulation, build strong bones and kill pains etc and has therapeutic effects on arthritis, boneaches, torn waist muscles, cruises, swelling, side paralysis etc. So far around 40 species of Flemingia philippinensis have been identified, 16 species and one variant can be found in China, mainly located in southwestern, midshouthern and southeastern provinces of our country. Flemingia philippinensis abounds in phenol, flavone, tannin, saccharide, sterol, alkaloid and amino acid etc, among them the content of flavone is relatively higher. Flemingia philippinensis has been used in patients for many years with definite pharmaceutic actions. Since it is added to the phamaceutical complex with its original root, its phamaceutical actions are not significant.In order to clarify the active component of Flemingia philippinensis and expand its application in pharmacology, the present study is to optimize the extraction conditions for obtaining the total flavone through Flemingia philippinensis coarse powder. Since the solubility of flavone varies with the different structure and existing state, so it is necessary to determine the type of solvents and then take the solvent concentration, extracting temperature, time and amount into account. Fix the proper range of the above factors through single factor experiment and through orthogonal experiment, based on the harvesting content of total flavone, to find out the effects of solvent concentration, extracting temperature, extracting time and volume of solvents on the total flavone harvest to determine the best extraction techniques.Flavones contain multiple molecules of phenolic hydroxyl group which confer them the antioxidative abilities. The present study is to test the scavenging and reducing abilities of total flavones to hydroxyl free radicals and superoxide anion via H2O2/Fe2+ system in which hydroxyl free radicals and superoxide were generated via Fenton reaction and pyrogallol auto-oxidation method; Through induction and non-induction two systems, the MDA level test was utilized to determine the protective effects of total flavones against oxidative damage induced by Fe2+ and H2O2 in vitro; Haematolysis rate of red blood cells was tested to verify that if total flavone from Flemingia philippinensis could inhibit the red blood cell haematolysis due to autooxidation of red blood cell and oxidative damage caused by Fe2+.Hyperlipemia is characterized by lipid metabolism disorder and lipoprotein superoxidization, which are the primary cause for atherosclerosis. AS is the incentive for cardiovascular diseas. Therefore, the key measure to prevent the development of AS is to control hyperlipemia effectively. There are researches showed that free radicals is closely related to the development and progression of AS, very low density lipoprotein can be oxidized easily by free radicals to form oxidative low density lipoprotein and result in AS and cardiovascular diseases. Hyperlipemia rat models were given Flemingia philippinensis total flavone at the dose of 10 mg/kg, 20 mg/kg, 40 mg/kg to explore the effects of total flavones on the level of serum and liver total cholesterol(TC), triglyceride(TG), high density lipoprotein cholesterol (HDL-c), low density lipoprotein cholestero(lLDL-c), superoxide dismutase(SOD), malonaldehyde(MDA), glutathion(GSH), hydrogen peroxide(H2O2), nitric oxide(NO), nitric oxide synthase(NOS)and find out if the flavone can reverse the lipid metabolism disorders induced by experimental hyperlipemia and inhibit the secondary damages caused by hyperlipemia. The above test were to demonstrate that if the total flavone could remove free radicals and protect the expeimental rats from oxidative stress and prevent the development of AS. The morphology of endothelial cells and liver as well as the expression of iNOS and VCAM-1 in aorta were examined to find out if the flavone could protect the them from hyperlipemia.The best extracting technique for Flemingia philippinensis total flavone based on the experiment results and statistics analyses was the following: 50% ethanol as solvent, the ratio of Flemingia philippinensis to solvent1:20, temperature 50℃,the harvesting rate was 1.41%. Acute toxicity test showed that the flavone extract low grade chemical. The preliminary quantitation test indicated that the extract contained flavoid, flavonol and flavonone.In vitro antioxidation experiment, Flemingia philippinensis flavone could scavenge O2-,·Oh , H2O2,reduce Fe2+ in a dose-effect manner, decrease the MDA level induced by autooxidation and oxidative stress derived from Fe2+ and H2O2, inhibit the haemolysis of red blood cells, which indicated that Flemingia philippinensis flavone could act as a natural antioxidative agent.Hyperlipemia rat model was successfully established by feeding the rats with the high level of lipid diet, the model rats were classified into high lipid diet group, flavone treated group which was further into high, medium and low dose subgroups. Normal rats were used as control. There was a significant decrease in the serum and liver level of TC, TG, LDL-c, MDA and a significant increase in the level of HDL-c, SOD, T-AOC, NO, NOS compared to high lipid diet group, which indicated that the flavone could prevent the development and progression of AS.There was a significant increase in the expression of iNOS in Flemingia philippinensis flavone high dose subgroup in a dose-effect manner, the iNOS was located in the macrophages and foam cells which was the center of atherosclerosis plaque by aorta immunohistochemistry staining.There was a significant decrease in the expression of VCAM-1 in vessel wall and monocytes in rats from Flemingia philippinensis flavone group compared to high lipid diet group, which indicated that the action mechanisms of how Flemingia philippinensis flavone preventing the development of AS was to upregulate the expression of key enzyme in the synthesis of NO and downregulate the expression of VCAM-1.
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