Ethanolic & aqueous extracts of Ocimum sanctum, Tinospora cordifolia, Withania somnifera, Avicennia officinalis, Rhizophora mucronata & Shilajit were included in the present in vitro study. Pepsin was used as a substitute for HIV-protease to evaluate effect of these extracts, as pepsin has great structural and functional similarities with HIV-protease. Pepsin assay could be used for preliminary screening of natural products for probable HIV-protease inhibitory activity. The use of combination antiretroviral therapy has yielded clinical benefits for HIV-infected patients, however, it has also...