MTT (3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide)
analysis was performed in 96-well plates. Briefly, 800–1500
cells/well were seeded in 200 ll of complete medium and treated
with the compounds after 24 h. Subsequently, cells were supplemented
with 25 ll of 5 mg/ml thiazolyl blue tetrazolium bromide
(Sigma–Aldrich) for 2 h. Thereafter, the medium was removed and
cells were lysed with 100 ll of DMSO. Absorbance was recorded at
570 nm by a 96-well-plate ELISA reader.