Fig 1. LA has a potent broad-spectrum anti-HIV activity with low, if any, cytotoxicity.

(A) Concentrations up to 62.5 μM (500 μg/ml) of LA were given to MT-4 cells, HEK293T cells and PBMCs. Cytotoxicity levels and CC₅₀s were determined spectrophotometrically using MTS/PES method. (B) Dose-dependent anti-HIV activity of LA in the CD4⁺ T-lymphoma cell line MT-4 against 3 laboratory HIV-1 strains (NL4.3, IIIB and HE) and 1 HIV-2 strain (ROD) with respectively the following IC₅₀s: 0.20 ± 0.03 μM (NL4.3), 0.22 ± 0.06 μM (IIIB), 0.22 ± 0.00 μM (HE) and 0.34 ± 0.04 μM (ROD). Mean IC₅₀ ± SEM up to 6 independent experiments is shown. (C). Evaluation of the IC₅₀s of LA against various clinical isolates representing different subtypes (A-H), irrespective of HIV-1 coreceptor tropism in primary cells (PBMCs and monocyte/macrophages [MDM]). Viral replication was measured using HIV-1 p24 Ag ELISA with exception of p27 HIV Ag ELISA for BCF-06 (group O). The IC₅₀s for viral inhibition were as follows: 0.10 ± 0.03 μM (UG273); 0.12 ± 0.06 μM (US2); 0.20 ± 0.05 μM (BK132); 0.15 ± 0.04 μM (ETH2220); 0.19 ± 0.01 μM (DJ259); 0.19 ± 0.04 μM (SE365); 0.16 ± 0.04 μM (BZ163); 0.13 ± 0.08 μM (BCF-DIOUM); 0.17 ± 0.08 μM (HH8793); 0.24 ± 0.07 μM (BCF-KITA); 0.07 ± 0.05 μM (BCF-06) and 0.11 ± 0.02 μM (BaL). Mean IC₅₀s ± SEM from 2–6 independent donor experiments is shown. (D) Dose-dependent effect of LA on the giant cell (syncytia) formation between persistently HIV-1 IIIB-infected T cells (HUT-78/IIIB) and non-infected CD4⁺ target SupT1 T cells. Percentage syncytia inhibition was measured by flow cytometry. Mean ± SEM of 3 independent experiments is shown.