Inhibition of Cytochrome P450 Activities by Sophora flavescens Extract and Its Prenylated Flavonoids in Human Liver Microsomes

Figure 4

Concentration-dependent inhibition of bupropion 6-hydroxylation and midazolam 1'-hydroxylation by kushenol I with (○) or without (●) preincubation in the presence of an NADPH-generating system; microsomal- (a) and recombinant CYP2B6- (b) mediated bupropion 6-hydroxylation and microsomal- (c) and recombinant CYP3A4- (d) mediated midazolam 1'-hydroxylation. CYP activities are expressed as the relative percentage of the activity in the control. Each data point represents the mean of triplicate experiments.

(a)

(b)

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(d)