FIG 3.

Arbidol combined with the approved drug aripiprazole causes synergistic suppression of LASV and JUNV glycoprotein-bearing pseudoviruses. Vero cells were treated with various concentrations of a single drug or a two- or three-drug combination of arbidol (Arb), amodiaquine (Amo), and aripiprazole (Ari) before infection with LASV or JUNV pseudovirus. Triple A refers to the combination of the three drugs. At 24 h postinfection, luciferase activity was measured. To quantify the combination effects for each experiment, the fractional inhibitory concentration (FIC) score was calculated by dividing the observed IC₅₀ by the expected IC₅₀ for each combination. For LASV, data represent averages and standard deviations from 8 separate experiments, with Z scores of >0.6 (the average Z score was 0.71 ± 0.06) and where each condition was conducted in triplicate. The 1× concentrations of Arb, Amo, and Ari were 11, 8, and 12 μM, respectively. For JUNV, data represent averages and standard deviations from 6 separate experiments, with Z scores of >0.2 (the average Z score was 0.5 ± 0.11) and where each condition was conducted in triplicate. The 1× concentrations of Arb, Amo, and Ari were 8, 12, and 5 μM, respectively. FICs of <1 suggest synergy. P values are derived from one-way ANOVA using Tukey’s multiple-comparison test in GraphPad Prism. ns, not significant.