Possible antiviral activity of montelukast against Herpes Simplex Virus type-1 and Human Adeno Virus in vitro

Montelukast (MLS) is used for the treatment of various allergic reactions. Viral infections are important, especially in exacerbation of allergic diseases. In this study, the apoptotic/necrotic responses of Herpes Simplex Virus (HSV-1 and Human Adenovirus (HAdV) isolate in HEp-2 and Vero cell cultures were compared with the presence or absence of non-toxic doses of pure MLS. The non-toxic dose of pure MLS for both cell lines was found to be 9.76 mu g/ml. The apoptotic cell (APC) ratios of HEp-2 cells infected with HSV and HAdV were 12.5 and 9.1% before MLS and 10.3 and 7.7% after MLS, respectively. The necrotic cell (NEC) ratio of HEp-2 cells infected with HSV and HAdV were found 26 and 20% before MLS and were found to be 22.0 and 18.7% respectively after MLS. APC ratio of Vero cells infected with HSV and HAdV were found 16 and 12.85% before MLS and were found to be 14.6 and 10.4% respectively after MLS. NEC ratio of Vero cells infected with HSV and HAdV were found to be 34 and 28.2% before MLS and were found to be 30 and 26.4% respectively after MLS. The tissue culture infectious doses (TCID50) values of HSV-1 for HEp-2 cells and Vero cells without MLS were 10-(5,25)/0.1 ml and 10-(4,95)/0.1 ml, with MLS were 10-(4,15)/0.1 and 10-(3,75)/0.1 ml, respectively. The TCID50 values of HAdV for HEp-2 cells and Vero cells without MLS were 10 -(7,0)/0.1 and 10-(6,75)/0.1 ml, with MLS were 10-(6, 25)/0.1 and 10-(5, 75)/0.1 ml, respectively. Although the methods applied in this study provides opportunities for morphologic diagnosis; results suggest the possible antiviral effect of montelukast.