In vitro Broad Antiviral Function against HBV, HSV, H3N2 Replication byBaicalin and Oroxylin A-7-O-ÃÂ-D-Glucoside

Flavonoids have been previously shown to possess anti-viral activities In vitro. Oroxylin A-7-O-β-D-glucoside (OAG), a flavonoids produced by microbial conversion, and its substrate baicalin, were assayed for antiviral function against hepatitis B virus (HBV), herpes simplex virus type 2 (HSV-2) and influenza A virus (H3N2). Incubation with 100 μg/ml OAG or baicalin for 9 days reduced human HBV-transfected liver cell line HepG2 2.2.15 secretion of Hepatitis B surface antigen (HBsAg) by 83.17%, and 47.175%, respectively, and Hepatitis B e antigen (HBeAg) by 27.35%, 25.56% respectively. OAG and baicalin inhibited HSV-II-induced cell death in a concentration dependent manner (ranging from by 75% and 62.5%, respectively at 12.5 μg/ml and 50%, 37.5%, respectively at 6.25 μg/ml). OAG (100 μg/ml) and biacalin (50 μg/ml) also effectively inhibited H3N2-induced toxicity in MDCK by 62.5% and 50%, respectively. In summary, OAG and baicalin could inhibit several viruses In vitro and OAG was more potent than baicalin. OAG may represent a candidate antiviral with broad activity against HBV, HSV-2 and H3N2 infection.