Evaluation of Ocimum sanctum and Tinospora cordifolia as Probable HIV-Protease Inhibitors

Abstract

Ethanol extracts of Ocimum sanctum Linn. and Tinospora cordifolia (Willd.) Miers ex Hook. f. & Thoms. were included for the present in vitro study. Pepsin was used as a substitute for HIV-protease to evaluate inhibitory activity of these extracts, as pepsin has close resemblance with HIV-protease in proteolytic activity. Extracts of O. sanctum and T. cordifolia showed potent inhibitory activity with IC50 values of 123.73 and 11.20 µg/ml respectively. In our earlier study, these extracts exerted their anti-HIV activity via multiple mechanisms of action; viz., interference with the gp120 / CD4 interaction and inhibition of HIV-reverse transcriptase. In the present study, they also showed potent inhibitory activity against pepsin enzyme, suggesting that they may be useful as HIV protease inhibitors. The inhibitory activity could be attributed to flavonoids and phenolic content respectively.