Metabolism of glycyrrhizin and baicalin by human intestinal bacteria

By human intestinal bacteria, glycyrrhizin (18β-glycyrrhetic acid β-D-glucuronyl α-D-glucuronic acid, GL) and baicalin (baicalein β-D-glucuronic acid) were metabolized to glycyrrhetinic acid and baicalin, respectively. However, α-glucuronidase of Bacteroides JY-6 isolated from human intestinal bacteria hydrolyzed GL or 18β-glycyrrhetinic acid α-D-glucuronic acid to 18β-glycyrrhetic acid but did not baicalin. However, E coli β-glucuronidase from human intestinal bacteria hydrolyzed baicalin to baicalein, but did not GL. β-Glucuronidase of mammalian tissues hydrolyzed both GL and baicalin.ope