Effect of dsRNA from π6 Bacteriophage on Herpetic Infection in Cell Culture and an Animal Model

Abstract

The double-stranded (ds) RNA from π6 bacteriophage inhibited herpes simplex virus type 1 (HSV-1) and HSV-2 infection in MA-104 cells but not in Vero cells. HSV-2 was more sensitive to this effect than HSV-1, with the HSV-2 ED₅₀ being 0.25 μg/ml and the HSV-1 ED₅₀ 1.68 μg/ml. On genital infection by HSV-2 in guinea pigs, π6 dsRNA was more effective by intravaginal (p < 0.05) than by intraperitoneal administration. A single dose of dsRNA of 600 μg/kg by intravaginal route modified favorably the natural course of the genital herpes in the treated animals (p < 0.001). Compared with the infected controls, they showed a faster recovery with better healing of lesions; and the number and severity of recurrence was low. No mortality was observed and the control infected animals showed a mortality of 39%. Sera from dsRNA-treated animals showed antiviral activity with a 50% placque-depressing dose (PDD₅₀) of 10^1.5/150 μl; no antiviral activity was found in sera either from control infected or uninfected animals. No adverse effect was observed on the rate of growth of uninfected dsRNA-treated controls.