CHEMBL5737802

Determination of Antiviral Activity: The cytopathic effect (CPE) inhibition test is used for measuring the antiviral effect. Monolayer cells in 96-well plates are inoculated with 0.1 ml virus suspension containing 100 CCID50. After an hour for virus adsorption (two hours in the case of HRSV-A2) in a humidified atmosphere at 37° C. and 5% CO2, excessive virus is discarded and cells are inoculated with 0.2 mL of maintenance medium containing serial 0.5 lg dilutions of the tested preparation. Mock-infected cells are left for cell and toxicity controls. The virus CPE is scored daily by inverted light microscope (Olympus CK40, Japan) at 125× and 400× magnification on a 0-4 basis (4 representing total cell destruction) till the appearance of its maximum in the virus control wells (with no compound in the maintenance medium)—the 48′ hour p.i. for PV1, 72nd hour for HRSV-A2 and the 4th day (96th hour) p.i. for HAdV-2. When maximum CPE in the virus control wells is reached, cells are processed according to the neutral red procedure described above. The percent of virus CPE protection is calculated by the following formula [Pannecouque et al., 2008]:meanOD Test - meanOD VC meanOD TC - meanOD VC × 100(ODTest−ODVC)/(ODTC−ODVC)×100(%), where ODTest is the mean optical density (OD) of the test sample, ODVC—the absorbance of the virus-infected control (no compound in the maintenance medium), and ODTC—the OD of the mock-infected control (toxicity control).The 50% virus inhibitory concentration (IC50) is determined by applying the regression analysis with the help of Origin 6.1 computer program and it is expressed as the concentration that achieves 50% protection of virus-infected cells.