The activities of P450s, CarE, and GST were examined using an ELISA kit (Shanghai Hengyuan Biotechnology Co., Ltd., Shanghai, China) following the manufacturer’s instructions. The diluted standard substance and reagents in the kit and enzyme protein were added to a 96-well plate according to the manufacturer’s instructions. After the reaction had finished, the OD value at 450 nm was determined using a microplate reader. A standard curve was drawn according to the concentrations of the standard substance and the corresponding OD values, and then the enzyme activities were calculated based on the standard curve.
