2.8 Lactate dehydrogenase (LDH) release assay
The release of cytoplasmic LDH is indicative of compromised cell membrane integrity, which signifies cellular demise41. The LDH content in the cell supernatants was quantified using an LDH kit, following the instructions provided by the manufacturer. The medium solution was added to each well of a 24-well plate placed within an optically clear 96-well plate for subsequent coupled enzymatic reaction. The LDH Reaction Mix was added to each well, mixed thoroughly, and incubated at 37℃ for 30 minutes to generate a brownish-red product. The absorbance of the product was measured spectrophotometrically at 450 nm using a microplate reader (Bio-Rad, Hercules, California, USA).