To evaluate the cytotoxicity of MLE and OA, the MTT [3-(4,5- Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide Assay] assay was performed. Cells were seeded at a density of 1 · 105/ml and treated with various concentrations of MLE and OA for 24 h. After exposure, media were removed, and the cells were washed with phosphate-buffered saline (PBS). Thereafter, the medium was changed to the one containing MTT (5 mg/ml) for 4 h incubation. The viable cell was directly
proportional to the production of formation. Following dissolution in isopropanol, the result was read at 563 nm with a
spectrophotometer (Beckman DU640