Epicatechin and Cocoa Extract Viability

The viability of cells was determined by MTT assay. SH-SY5Y cells were plated in 96-well plates (2 × 10⁴ cells/well), cultured for 24 h at 37 °C in 5% CO₂ and were differentiated for 5 days with 10 µM RA. The differentiated neurons were treated with serially diluted concentration of epicatechin (epi) or cocoa extract. After 3 and 18 h of incubation, 20 µL of a MTT solution (5 mg/mL in PBS) was added to each well and incubated for an additional 2 h at 37 °C in 5% CO₂. Formazan crystals formed in the wells were solubilized in 200 µL of Dimethyl sulfoxide (DMSO). Absorbance was measured at 570 nm wavelength employing a microplate reader PowerWaveTM XS (BioTek Instruments, Inc., Winooski, VT, USA). The viability was calculated in comparison to control experiments in which a solvent control was added in place of epicatechin or cocoa extract and that was used as a 100% viable reference [34 (link)].