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

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.

Effect of ketoprofen on intravenous pharmacokinetics of ganciclovir in chukar partridges (Alectoris chukar)

“…Ganciclovir is indicated in the treatment of infections such as retinitis, colitis, pneumonitis, and encephalitis caused by human cytomegalovirus, which is the prototypic member of the β herpesvirus subfamily (Boeckh & Geballe, 2011; Crumpacker, 1996). In addition, ganciclovir has more in vitro efficacy against Equine herpesvirus and Feline herpesvirus (Van der Meulen et al, 2006; Oliveira et al, 2018). Ganciclovir was effective in respiratory infection induced by Equid alphaherpesvirus ‐ 1 (Mortari et al, 2019), equine coital exanthema induced by Equid alphaherpesvirus ‐ 3 in mares (Vissani et al, 2020), ocular lesions induced by Canine herpesvirus ‐ 1 in dogs (Ledbetter et al, 2018), and in the treatment of ducks infected with duck hepatitis B (Niu et al, 1993).…”