Assessment of Cell Viability
Following the desired treatments, the cell viability was determined using MTT reduction assay.24) Briefly, MTT was added to the treated cells at a final concentration of 1 mg/mL in PBS and the cells were incubated for 3 h at 37°C. The culture media were carefully removed from the wells and dimethylsulfoxide was added to the cells to dissolve the formazan crystal products. The absorbance was read at 550 nm using a microplate reader (SpectraMax M2e, Molecular Devices, Sunnyvale, CA, U.S.A.). The cell viability was expressed as percentage of control-treated cells.