Dose-response curves and citotoxicity of 1,4-pyran naphthoquinones 9b and 9c in DENV-2-infected Vero cells.

Vero cells were infected with DENV-2 at an m.o.i of 0.1 in the presence of increasing concentrations of the 1,4-pyran naphthoquinones 9b and 9c. 72 hours after infection the cell-free supernatants were harvested and processed for the quantification of produced viral progeny by qPCR. (A) The percentage of inhibition was calculated using the ΔΔCT values. (B) The concentration of each compound that inhibit 50% of the viral replication (IC₅₀) was determined by a Hill’s regression curve after logarithmic interpolation of the data using the GraphPad 6 software. (C) The potential cytotoxic effect of each compound was evaluated in uninfected cells by the vital neutral red staying and represented as percentage of the untreated control. Data represent mean values ± standard deviations (SD) for three independent experiments.