Inhibitory effects of Sudanese medicinal plant extracts on hepatitis C virus (HCV) protease

One hundred fifty-two methanol and water extracts of different parts of 71 plants commonly used in Sudanese traditional medicine were screened for the ir inhibitory effects on hepatitis C virus (HCV) protease (PR) using in vit ro assay methods. Thirty-four extracts showed significant inhibitory activi ty (greater than or equal to 60% inhibition at 100 mug/mL). Of these, eight extracts, methanol extracts of Acacia nilotica, Boswellia carterii, Embeli a schimperi, Quercus infectoria, Trachyspermum ammi and water extracts of P iper cubeba, Q. infectoria and Syzgium aromaticum, were the most active (gr eater than or equal to 90% inhibition at 100 mug/mL), From the E, schimperi extract, two benzoquinones, embelin (I) and 5-O-methy lembelin (II), were belated and found as potent HCV-PR inhibitors with IC50 values of 21 and 46 muM, respectively. Inhibitory activities of derivative s of I against HCV-PR as well as their effects on other serine proteases we re also investigated. Copyright (C) 2000 John Wiley & Sons, Ltd.