In Vitro Antiviral Effect of

Influenza is a viral infectious disease with frequent seasonal epidemics causing world-wide economical and social effects. Due to antigenic shifts and drifts of influenza virus, long-lasting vaccine has not been developed so far. The current annual vaccines and effective antiviral drugs are not available sufficiently. Therefore in order to prevent spread of infectious agents including viruses, antiseptics are considered by world health authorities. Small particles of silver have a long history as general antiseptic and disinfectant. Silver does not induce resistance in microorganisms and this ability in Nano-size is stronger. The aim of this study was to determine antiviral effects of Nanosilver against influenza virus. TCID50 (50% Tissue Culture Infectious Dose) of the virus as well as CC50 (50% Cytotoxic Concentration) of Nanosilver was obtained by MTT (3- [4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide, Sigma) method. This compound was non-toxic to MDCK (Madin-Darbey Canin Kidney) cells at concentration up to 1 µg/ml. Effective minimal cytotoxic concentration and 100 TCID50 of the virus were added to the confluent cells. Inhibitory effects of Nanosilver on the virus and its cytotoxicity were assessed at different temperatures using Hemagglutination (HA) assay, RT-PCR (Reverse Transcriptase-Polymerase Chain Reaction), and DIF (Direct Immunofluorescent). RT-PCR and free band densitometry software were used to compare the volume of the PCR product bands on the gel. In this study it was found that Nanosilver has destructive effect on the virus membrane glycoprotein knobs as well as the cells.