TABLE 4

Kinetic parameters for HFC glucuronidation by expressed UGTs and inhibition by silybin Expressed UGTs were pretreated with alamethacin (50 μg/mg protein) and incubated with varying concentrations of HFC to determine kinetic parameters as described under Materials and Methods. The data were fitted to either Michaelis-Menten (K_m) or Hill kinetics (S₅₀). IC₅₀ values for inhibition of HFC glucuronidation by silybin were determined at the K_m concentrations for each UGT isozyme. The enzyme rates shown represent the mean and standard deviation from three separate experiments.