2.2.5. Cell Viability Assay

HUVEC metabolic activity was evaluated with the MTT assay. Cells were plated at a density of 6 × 1000 cells/well in a 96-well plate. After 16–18 h, HUVEC were treated with 0.1 µg/mL of TNF-α. After 4, 16, 24, or 48 h, the cells were washed with PBS, and MTT solution (50 µL of 5 mg/mL) was added to each well for 4 h at 37 ◦C. Subsequently, the medium was removed, and DMSO (Sigma-Aldrich, St. Louis, MO, USA) was added (200 µL/well) to solubilize the formazan crystals. Optical density was measured at 570 nm with the Tecan microplate reader (Thermo Scientific, Waltham, MA, USA).
