Evaluation of antiviral agents for adenovirus using the MTT method in vitro

PURPOSE: Currently, there is no effective treatment for adenoviral conjunctivitis. We evaluated the antiviral inhibitory effect of four antiviral agents against adenovirus (ADV) in vitro. METHODS: Viruses used for the experiment were ADV type 4 (ADV 4), type 8 (ADV 8) and type 37 (ADV 37). We examined four antiviral agents, i.e., cidofovir (HPMPC), zalcitabine (ddC), foscarnet (PFA), and acyclovir (ACV). 50% effective concentration (EC50), 50% cytotoxic concentration (CC50) and selectivity index (SI) of compounds were determined for ADV infection in HEp-2 cells using the 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. RESULTS: HPMPC and ddC showed an inhibitory effect against all three ADVs. In particular, ddC showed more potent and selective inhibition against ADV than HPMPC. PFA and ACV were ineffective against ADV. CONCLUSIONS: HPMPC and ddC were inhibitory against ADV 4, ADV 8 and ADV 37 replication in vitro. The MTT method is rapid and simple for the screening of antiviral agents. We think this method is also very useful for the screening of anti-ADV agents.