MTT assay on viability of SH-SY5Y and SK-N-SH cells

The SH-SY5Y and SK-N-SH cells at their logarithmic growth phase were collected following 0.125% trypsin digestion and adjusted to a concentration of 1×10⁸ cells/l. Cells were seeded into 96-well plates at a concentration of 10,000 cells/well. After serum starvation for 24 h, the wells were divided into different groups in sextuplicate as mentioned above and 20 µl MTT (5 g/l) was added to each well. The plates were incubated at 37°C for another 4 h. Subsequently, MTT solution was removed and 150 µl DMSO was added to each well. The plates were shook for 10 min to dissolve the purple formazan crystals. The light absorbance was measured at a wavelength of 490 nm using a microplate reader. Cell survival rate was calculated using the following equation: Survival rate (%)=A_{490 nm (experiment)}/A_{490 nm (control)} ×100%.