In vitro antiviral activity of ribavirin against picornaviruses

The in vitro antiviral activity of ribavirin (Rbv; 1-beta-D-ribofuranosyl-1,2,4-triazole-3-carboxamide) against selected members of the Picornaviridae is described. When antiviral activity was determined by reduction of infectious virus progeny, Rbv was active against human rhinovirus type 2 (HRV-2) and poliovirus type 1 (Polio-1) in both a drug concentration and multiplicity of infection-(MOI) dependent response. However, an antiviral activity rating assay based on the reductions of cellular cytopathic effects (CPE) indicated that Rbv was active against human rhinoviruses, but was less active against polioviruses. Prophylactic administration of Rbv significantly improved virus yield reduction, especially in Polio-1. SDS polyacrylamide gel electrophoresis (SDS-PAGE) of HRV-2- and Polio-1-infected cell lysates demonstrated that Rbv inhibited the synthesis of viral-specific proteins. Although actinomycin D (Act D) did not significantly influence picornavirus yields, when added concomitantly with Rbv, Act D reversed Rbv's antiviral effect.