Anti-HIV-1 activity of compounds derived from marine alga Canistrocarpus cervicornis

Abstract

This paper describes the inhibition of human immunodeficiency virus-type 1 (HIV-1) virus replication in tumor cell lines by marine dolastanes (1–3) and secodolastane diterpenes (2) isolated from brown alga, Canistrocarpus cervicornis. Cells were exposed to CXCR4-tropic HIV-1 and treated with different concentrations of the compounds. We observed that the compounds inhibit HIV-1 replication in a dose-dependent manner with EC₅₀ values of 0.35, 3.67, and 0.794 μM for diterpenes 1, 2, and 3, respectively. We demonstrate that these compounds present no cytotoxic effect with CC₅₀ values ranging from 935 to 1910 μM. We also analyzed the virucidal effect of these compounds and observed that dolastane diterpenes 1 and 3 present a potent effect on a HIV-1 infectivity of up to 99 and 87 %, respectively, at a concentration of 25 μM. No virucidal effect was observed with secodolastane diterpene 2. Our results support further investigations on compounds 1 and 3 for pre-exposure prophylaxis (PrEP) and suggest that the microbicidal compounds act before virus penetration into target cells. We propose that these marine diterpenes could be considered as a potential HIV-1 therapy.