Radix puerariae polypeptide with antioxidant activity and application thereof

The invention belongs to the field of active peptides, and particularly relates to a kudzuvine root polypeptide with antioxidant activity and a preparation method and application thereof. The amino acid sequence of the kudzuvine root polypeptide is YLWVGA, namely, Tyr-Leu-Trp-Val-Gly-Ala. The polypeptide YLWVGA disclosed by the invention has a remarkable protection effect on ethanol-induced oxidative damage of HepG2 cells, and ethanol-induced oxidative stress is inhibited by reducing the release amounts of ALT, AST and LDH and improving the activity of antioxidant enzyme, so that the activity of protecting the oxidative damage of the HepG2 cells is exerted. The natural polypeptide YLWVGA has the advantages of being high in antioxidant activity, small in molecular weight, easy to digest and absorb and the like, and can be applied to functional food or health care products for relieving oxidative stress damage.