The antiviral efficacy of compounds was assessed in MDCK cells through quantification of their ability to mitigate virusinduced cell death. MDCK cells were cultured in a 96-well plate (2 × 10 4 cells per well) in E10 medium and incubated at 37°C under 5% CO2 overnight. The wells were then washed once with phosphate-buffered saline (PBS). Compounds were added at a concentration of 50 μM, along with 9 x TCID50 of the virus. The cells were subjected to individual compound incubation as a means to evaluate its cytotoxic effects. The surviving cells were measured with the colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The plate was placed in a 5% CO2, 37°C incubator for 72 h. After incubation, the cell wells were rewashed with PBS, and 50 μL of MTT solution was added to each well, followed by incubation for 3 h at 37°C with 5% CO2. The medium was removed, and 200 μL of dimethyl sulfoxide was added to each well to dissolve the formazan crystals. The absorbance of each well was measured at 570 nm on an ELISA Reader (Molecular Devices; Lmax II384). A control group of drug ITA19 with a concentration of 5 μM was employed 43 .