Kudzu is a vine that grows mainly in China and in the southern United States. It grows to eventually cover other vegetation entirely in some cases. It is useful for supporting the cardiovascular system. The root is traditionally used in China for headaches, diarrhea, dysentery, intestinal obstruction, and stomach flu. Plant extracts have been shown to lower blood sugar and blood pressure. Flowers have been used to reduce stomach acid and awaken the spleen. The stem is poulticed for sores, swellings, and mastitis. The tea is used as a gargle for sore throat. Roots have been shown to contain more estrogenic isoflavones, daidzein, and genistein than soybeans. Genistein may prevent development of tumors. Daidzein has been shown to reduce blood pressure and venous obstruction. A root extract was shown to have 100 times the antioxidant activity of Vitamin E. Kudzu extracts have also been found to stimulate regeneration of liver tissue while protecting against liver toxins.