2.4. MTT Assay

BV2 microglial cells were seeded into 96-well plates at a density of 4 × 10³ per well with amentoflavone at different concentrations (0, 0.01, 0.1, 1, 10, 25, 50, 75, and 100 μM) in the absence of FBS. After 24 h incubation, cell viability was determined by MTT assay. In brief, MTT (5 mg/ml) was added into well plate for cell culture for 4 h at 37°C. The cell supernatant was then removed and 200 μl of DMSO solution was added. Optical density was detected at 580 nM with a microplate reader.