ANTIVIRAL ACTIVITY OF MELISSA OFFICINALIS AQUEOUS EXTRACT AGAINST PSEUDORABIES VIRUS

Aujeszky's disease is a contagious illness, causing severe economic losses in pig farming worldwide. Thus the prevention and control of the disease is of paramount importance. Discovery of antiviral agents, effective against PsRV, the causative agents of Aujeszky's disease, will facilitate those efforts. Melissa officinalis L. (Lamiaceae) is a plant with well-known antiviral activity. The aim of this study was to verify the in vitro antiviral effect of M. officinalis on pseudorabies virus (PsRV). The experiments were performed on MDBK cell line and cell culture from rabbit kidney (RK-8), using different dilutions of total aqueous extract of M. officinalis. Cytotoxicity and antiviral effect of the extracts were tested. Evaluation of the antiviral activity was based on the presence of cytopathic effect (CPE). M. officinalis extracts showed a marked protective effect when added to the cell cultures along with PsRV. Pretreatment of the viral suspension with M. officinalis extracts resulted in a lack of any CPE. Pre-treatment of the cells before viral adsorption, and post-infectious treatment with the extracts did not affect the viral replication.