Fig. 3.

Dixon plots showing the inhibition of (S)-warfarin 7-hydroxylation by silybin A (A) and silybin B (B) in HLMs. HLMs (0.1 mg/ml) were incubated with (S)-warfarin (1–15 μM) and flavonolignan (1–80 μM silybin A or 1–50 μM silybin B) for 30 min. Reactions were initiated by the addition of NADPH (1 mM). Symbols denote means of duplicate incubations. Solid lines denote regression lines through values generated from a simple mixed-type inhibition model using WinNonlin (version 5.0.1).