In vitro activity of six antiviral drugs against equid alphaherpesvirus type 1 indicates ganciclovir as promising drug for in vivo studies

A atividade in vitro de seis drogas antivirais contra o alfaherpesvírus equino tipo 1 indica que o ganciclovir é uma droga promissora para estudos in vivo

ABSTRACT:

Equid alphaherpesvirus type 1 (EHV-1) is distributed worldwide and is a major agent of abortion, respiratory and neurological disease in horses. No specific treatment is available for EHV-1 infection, yet the potential of antiviral therapy has been explored. In this study we investigated the in vitro activity of Acyclovir, Ganciclovir, Foscarnet, Famciclovir, Vidarabina and Cidofovir against EHV-1. For this, the MTT test was performed, in which all the tested drugs showed no toxicity up to 200μg/mL. Subsequently, different drug concentrations were submitted to viral plaque reduction assays in cell culture. The selectivity index (SI) of the compounds was determined using the cytotoxic concentration for 50% of cells (CC₅₀), obtained by MTT, and effective drug concentration to inhibit by 50% the number of viral plaques (EC₅₀). Ganciclovir (SI: 490; EC₅₀: 1.9 μg/mL) was the most efficient and safest drug against EHV-1, followed by Cidofovir (SI: 150, EC₅₀: 5.7μg/mL), Acyclovir (SI: 37.4, EC₅₀: 22.2μg/mL), Famciclovir (SI: 25.1, EC₅₀: 24.5μg/mL), Vidarabine (SI: 12.2, EC₅₀: 40.9μg/mL) and Foscarnet (SI: 6.9, EC₅₀: 49.5 μg/mL), respectively. These results indicated that Ganciclovir (followed by Cidofovir), is a promising candidate for use in in vivo experiments.

Key words:
EHV-1; plaque assay; Acyclovir; Ganciclovir; Foscarnet; Famciclovir; Vidarabine; Cidofovir