Alizarin weakly inhibits CYP2A6 and CYP2E1. Alizarin shows competitive inhibition against CYP1B1 with Ki of 0.5 μM. Alizarin deduces the mutagenicity of MeIQx, which induced by each CYP1A2 or CYP1B1, while does not effectively reduce the mutation induced by B[a]P. [1] Alizarin exhibits antioxidants against iodophenol-derived phenoxyl radicals, superoxide anion radicals and lipid peroxidation in rat liver microsomes. [2]