Abstract

DEZENGRINI, Renata et al. Activity of three antiviral drugs against bovine herpesviruses 1, 2 and 5 in cell culture. Pesq. Vet. Bras. [online]. 2010, vol.30, n.10, pp. 855-860. ISSN 0100-736X.  http://dx.doi.org/10.1590/S0100-736X2010001000008.

The activity of three anti-herpetic drugs (Acyclovir [ACV], Gancyclovir [GCV] and Foscarnet [PFA]) was tested against bovine herpesvirus 1 (BoHV-1), 2 (BoHV-2) and 5 (BoHV-5) in vitro using the plaque reduction assay. Different drug concentrations were tested against one hundred 50% tissue culture infectious dose (TCID₅₀) of the respective viruses. Drug concentrations lower than 200μg/mL resulted in viability rates of more than 80% for MDBK and Hep2 cells in the MTT test (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). The selectivity index (IS) of the drugs was calculated dividing the concentration of the drug that is cytotoxic for 50% of the cells (CC₅₀) by the concentration of the drug that was effective in reducing by 50% the number of viral plaques (EC₅₀) for the three herpesviruses. Thus, ACV was shown to be moderately active against BoHV-1 (EC₅₀: 112.9μg/mL; IS: 4.5), BoHV-2 (EC₅₀: 114.2μg/mL; IS: 4.5) and BoHV-5 (EC₅₀: 96.9μg/mL; IS: 5.3). GCV was effective against BoHV-2 (EC₅₀: 33.5μg/mL; IS: 16.6), moderately effective against BoHV-5 (EC₅₀: 123.2μg/mL; IS: 4.5) and poorly active against BoHV-1 (EC₅₀: 335.8μg/mL; IS: 1.7). PFA exhibited the highest antiviral activity, being the only drug that, at concentration of 100μg/mL, completely inhibited plaque formation by all three viruses. PFA was the most effective in vitro against BoHV-1 (EC₅₀: 29.5μg/mL; IS: 42.2), BoHV-2 (EC₅₀: 45.2μg/mL; IS: 27.6) and BoHV-5 (EC₅₀: 7.8μg/mL; IS: 160.6). Thus, the results indicate that PFA is a promising candidate for experimental therapeutic testing in vivo against bovine herpesviruses.

Keywords : Antivirals; BoHV-1; BoHV-2; BoHV-5; Foscarnet; Gancyclovir; Acyclovir.