Antiherpes virus effect of the red marine alga Polysiphonia denudata

Abstract

The water extract from the red marine alga Polysiphonia denudata (Dillwyn) Kutz. from the Bulgarian Black Sea coast selectively inhibited the reproduction of herpes virus type 1 and type 2 in cell cultures (EC50=8.7 to 47.7 mg/ml) as shown by the reduction of virus-induced cytopathic effect and viral infectivity. The virus-inhibitory effect was dose-related, strain-specific and depended on virus inoculum. The inhibition affected adsorption as well as the intracellular stages of viral replication. The presence of the extract throughout the whole replicative cycle was necessary for the full expression of the antiviral effect. In higher concentrations (MIC90=6.5 mg/ml) the extract exhibited strong extracellular virus inactivating activity.