Inhibition of axenic growth of <i>Leishmania</i> and reduction in parasite load by 17-AAG.

<p>(<b>A</b>) Axenic promastigotes were exposed to several concentrations of 17-AAG (25, 125, 500 nM) for 48 h and the number of viable parasites was assessed as described in Materials and Methods. Data are presented as the percentage inhibition of parasite growth related to untreated controls (4,754×10⁷). Bars represent means ± SD of one representative out of two experiments performed in sextuplicate (one-way ANOVA, Dunnett’s Multiple Comparison Test, ***<i>p</i><0.0001, post-test for linear trend, <i>p</i><0.0001). (<b>B, C</b>) Drug effects at early times after infection. Following 6 h of incubation with parasites, macrophage cultures were treated for 6, 24 and 48 h with specific concentrations of 17-AAG (25, 125, 500 nM); (<b>D, E</b>) Drug effects at later stages after infection. Following 6 h of incubation with parasites, macrophage cultures were reincubated for additional 48 h then submitted to treatment with specific concentrations of 17-AAG (25, 125, 500 nM). Bars represent means ± SD of one representative experiment out of two performed in sextuplicate (one-way ANOVA, Dunnett’s Multiple Comparison Test, *<i>p</i><0.05, **<i>p</i><0.001, ***<i>p</i><0.0001, post-test for linear trend, <i>p</i><0.0001).