Microwave-assisted extraction and antihyperlipidemic effect of total flavonoids from corn silk

The process of microwave-assisted extraction (MAE) of total flavonoids from corn silk and the hypolipidemia in animal models were studied. Influence of solvent concentration, microwave power, extraction time and dose of solvent were investigated and then, the orthogonal experiments were performed. Animal models of hyperlipidemia induced by high-fat diet were established. The serum levels were respectively measured, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C). The optimum extraction parameters were determined as follows: the ethanol concentration (60%); the power (600 W); the extraction time (16 min); the ratio of plant material to solvent (M/S) (1:20), and the yield of extract (4.55%). Corn silk total flavonoids (CSTF) significantly lowered the serum TC, TG and LDL-C levels. The serum lipid level was decreased by CSTF in hyperlipidemic animal models in a dose dependent manner.