Lactate dehydrogenase (LDH) cytotoxicity assay

LDH release was measured using CytoTox 96^® Non-Radioactive Cytotoxicity Assay (Promega, G1780) according to the manufacturer’s instructions. Briefly, cells were seeded in 96-well plate at density of 1 × 10⁴ cells/well. After overnight culture, cells were treated with Rotenone (Sigma, R8875) ranging from 0.001 to 100 μM for 24 hours. Cell culture media were collected and used for measuring LDH release. LDH levels was determined by recording absorbance at 490 nm using BioTek Epoch Microplate Spectrophotometer and the percent cytotoxicity was calculated per manufacturer’s instructions: Percent cytotoxicity = 100 × (Experimental LDH Release/ Maximum LDH Release).