Aqueous Two-phase Extraction And Amelioration Of Mitochondria Oxidative Damage Of Flavonoids From Tartary Buckwheat

Tartary buckwheat is a kind of coarse cereals growing only in chinese.As an excelent food medicine dual-use cereal crop with the certification of international FAO,tartary buckwheat has many biological functions,such as improving cardiovascular disease,enhancing insulin sensitivity,antibiosis,anticancer,antifatigue and so on.Flavonoids from tartary buckwheat is the most important bioactive compounds,which is considered to be closely related to the biological functions of tartary buckwheat.Mitochondrial oxidative damage is regarded as the root of causing many chronic diseases such as cardiovascular disease,alzheimer,Parkinson,diabetes,cancer and so on.However,researches show that basing on the sigficant antioxidant properties,flavonoids have good prevention and treatment effects on many chronic diseases.In our study,flavonoids were the main objective and antioxidant activity was the content,we discussed the mechanism of ultrasonic-assisted aqueous two-phase for flavonoids extraction from tartary buckwheat seeds.Moreover,we investigated the antioxidant activity of flavonoids extracted based on the two antioxidant mechanisms of SET and HAT,while,we also analysed the protective effect on mitochondria oxidative damage of mice liver.The main results are as follows:?1?Among the fifteen aqueous two-phase systems which was composed of two compounds: one of the organic solvents including ethanol,acetone,isopropyl alcohol,n-butyl alcohol and ethyl acetate,and another of inorganic salts including?NH₄?₂SO₄,K₂HPO₄ and Na₂CO₃),the system composed of acetone and?NH₄?₂SO₄ had the best yield of extraction for tartar buckwheat flavonoids,followed by the system of isopropanol and?NH₄?₂SO₄,and the lowest one was the ethyl acetate/Na₂CO₃ aqueous two-phase system.?2?The optimum condition for extraction was as follows: the ratio of liquid-solid was46.65 g/g with the mass concentration of ammonium sulfate of 22.86% under the ultrasonic temperature of 44.75?.Finally the yield of the flavonoids was 20.01±0.26 mg/g at the optimum conditions.?3?Comparing with flavonoids extracted by ethanol and methanol,the purity of flavonoids extracted by acetone/?NH₄?₂SO₄ aqueous two-phase reached 62.35% with an increase of 38.86% and 28.45%,respectively,while was still inferior to the extracts refined byAB-8 macroporous resin?77.91%?.The result showed that the aqueous two-phase extraction has a good initial purification effect.?4?All the antioxidant models basing on SET and HAT indicated that the flavonoids extracts from tartary buckwheat had a stronger antioxidant capacity.?5?The flavonoids extracts had a significant protective effect on mitochondria oxidative damage of mice live,it could effectively restrain the mitochondria swelling and the loss of membrane potential.At the same time,flavonoids extracts could significantly reduce the production of MDA.