2.7.2 Metabolic assay
The content of intracellular hydrogen peroxide was measured with a Hydrogen Peroxide Assay Kit (Beyotime, China). The NAD+/NADH and NADP+/NADPH were measured with a NAD+/NADH Quantification Kit and NADP+/NADPH Quantification Kit (Sigma-Aldrich), respectively. All kits were used according to the manufacturer’s instructions.