Antiviral activity of Terminalia

Hepatitis B Virus (HBV) is a causative agent of the most frequent viral infections of man. Since the non-human host range of HBV is restricted to a few animals, such as, chimpanzee, the development of new therapeutics for HBV has been hampered. Several cell lines were developed to identify potential therapeutics against HBV infection. One of these, the HepG2 2.2.15 cell line, was derived through transfection of a cloned HBVgene into a well-characterised human hepatoblastoma cell line HepG2, with which a standardized cell culture assay was established for potential anti-HBV active agents. Recently it was reported that the aqueous extracts of four plants, Terminalia chebula Retz., Sanguisorba officinalis Linn., Rubus coreanus Miq. and Rheum palmatum Linn. exhibited more than 50% inhibition of HBV DNA polymerase activity in vitro and showed potential antiviral effects against duck hepatitis B virus. Kim and others from South Korea examined the four plant extracts for antiviral effects against human HBV using a cell culture system with HepG2 2.2.15 cells. The extracts were assayed for the inhibition of HBV multiplication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HepG2 2.2.15 cells after an 8day treatment. All extracts decreased the levels of extracellular HBV viron DNA at concentrations ranging from 64 to 128 ~g/ml and inhibited the secretion of HBsAg dose dependently. Of the four tested plants, Terminalia chebula exhibited the most prominent anti-HBV activities [Kim et aI, Phytother Res, 2001, 15(8),718-720].