Selective and potent inhibition of dengue virus multiplication by the alkaloid anisomycin

QUINTANA, VM; CASTILLA, V; DAMONTE, EB; BRUNETTI, JE

San Diego

Congreso; 29th International Conference on Antiviral Research; 2016

International Society for Antiviral Research

In this work, we investigated the antiviral activity of anisomycin, a natural alkaloid, against dengue virus (DENV). The effect of anisomycin in Vero cell viability was assessed by the MTS method and the 50% cytotoxic concentration (CC50) was determined. In order to evaluate the antiviral activity, DENV-2 infected cells were treated with non-cytotoxic concentrations of anisomycin for 48 h and virus yields were quantified by plaque assay. The 50% effective concentration (EC50) was determined and the selectivity index (SI) was calculated as the ratio CC50/EC50. The compound was active against DENV-2 (SI = 172) and a 99.99% inhibition of virus yield was obtained at the highest non-cytotoxic concentration assayed (200nM) even in cultures infected with an m.o.i. of 50 PFU/cell. The compound did not exhibit virucidal effect and treatment of cells prior to infection did not affect virus multiplication. Time course experiments showed that extracellular and intracellular viral infectivity was highly inhibited even when anisomycin was added at 8h post-infection (p.i.). Furthermore, maximum inhibition of virus yield was obtained when the compound was present from 1 to 4 h p.i. Indirect immunofluorescence assays showed that anisomycin completely blocks viral protein synthesis. The compound was also active against the other DENV serotypes with SI values of 232, 217 and 87 for DENV-1, DENV-3 and DENV-4, respectively, whereas it was inactive against other RNA viruses such as poliovirus and Junín virus. Anisomycin is a potent and selective inhibitor of all four DENV serotypes that impaired the formation of infectious viral particles.