Preparation method of total flavonoids in persimmon leaves and application of total flavonoids in liver-protecting drugs and health foods

A preparation method of total flavonoids in persimmon leaves comprises the following steps: using 70% ethanol to be heated in water bath at a temperature of 75 DEG C to carry out reflux and extraction, using 70% ethanol to be heated by microwave radiation to carry out reflux and extraction or using 70% ethanol to be heated by ultrasonic waves to carry out reflux and extraction; combining extract,using 2% HCl aqueous solution to regulate the pH value to 5.5, enabling the extract to pass through LX-28 type large pore resin absorption columns or LX-38 type large pore resin absorption columns, washing until effluent is colorless, using 70% of ethanol solution for elution and collecting eluent; decompressing and concentrating the eluent at a temperature of 60 DEG C to obtain extract with relative density being 1.30-1.40g/cm , placing the extract into a freeze-drying oven and drying the extract at a temperature of minus 50 DEG C to obtain the total flavonoids in persimmon leaves. The invention also provides application of the active ingredients- total flavonoids in liver-protecting drugs and health foods. Drug effect tests show that the total flavonoids can reduce the contents of ALTand AST in the serums and MDA in the livers, increase the activities of SOD and CAT in the livers, reduce the injury degrees of the liver cells and play an important role in preventing and treating liver diseases.