Anti-HIV-1 activity of Acacia catechu extracts. TZM-bl cells were infected with HIV-1NL4.3 (MOI, 0.05) pretreated for 1 h with extracts prepared from A. catechu and incubated for 48 h in the presence or absence of extracts as described in Materials and Methods. Anti-HIV-1 activity at varying concentrations of the 50% ethanolic, aqueous stem bark extracts and AZT (1 μM), used as a positive reference control, has been shown. Y-axis represents the percent inhibition of HIV-1 infection. Values are expressed as mean ± SE of 3 different experiments performed in duplicates. *p < 0.05; **p < 0.001 (as compared to infected control group without any treatment).