"449798" . . "35" . "Drug Metabolism and Disposition" . . . . "Z(MSM6198959216)" . . . "7"^^ . . . . . "5"^^ . . "Lu\u017En\u00E1, Pavla" . "Silybin (a flavonolignan, the main component of silymarin, an extract from the seeds of Silybum marianum) has been used to date mostly as a hepatoprotectant. However, it also has other interesting activities, e. g., anticancer and hypocholesterolemic effects. It is also known that silybin can inhibit the activities of the cytochrome P450 (P450) enzymes. In this study, a weak interaction of silybin with human microsomal CYP2E1, 2A6, 2B6, 2C19, and 2D6 (IC50 >= 250 mu M) was found; a moderate inhibition was observed for CYP1A2 and 2C8. The most prominent inhibition effect was found with CYP3A4 and CYP2C9 (IC50 <= 50 mu M). Using mass spectometry detection, production of O-demethylated (the main metabolite) as well as hydroxylated derivatives of silybin formed by P450 enzymes was detected. The effect of different P450 inhibitors on the formation of O-demethylated product was also studied. In particular, a relatively specific inhibitor of CYP2C8 (quercetin) markedly inhibited the formation of this m"@en . . . "Papou\u0161kov\u00E1, Barbora" . . "Lemr, Karel" . . . "Silybin (a flavonolignan, the main component of silymarin, an extract from the seeds of Silybum marianum) has been used to date mostly as a hepatoprotectant. However, it also has other interesting activities, e. g., anticancer and hypocholesterolemic effects. It is also known that silybin can inhibit the activities of the cytochrome P450 (P450) enzymes. In this study, a weak interaction of silybin with human microsomal CYP2E1, 2A6, 2B6, 2C19, and 2D6 (IC50 >= 250 mu M) was found; a moderate inhibition was observed for CYP1A2 and 2C8. The most prominent inhibition effect was found with CYP3A4 and CYP2C9 (IC50 <= 50 mu M). Using mass spectometry detection, production of O-demethylated (the main metabolite) as well as hydroxylated derivatives of silybin formed by P450 enzymes was detected. The effect of different P450 inhibitors on the formation of O-demethylated product was also studied. In particular, a relatively specific inhibitor of CYP2C8 (quercetin) markedly inhibited the formation of this m" . "Silybin is metabolized by cytochrome P4502C8 in vitro" . . "Anzenbacher, Pavel" . "RIV/61989592:15310/07:00004833!RIV10-MSM-15310___" . . . "Human liver-microsomes; milk thistle; mass-spectrometry; silibinin; pharmacokinetics; inhibition; indinavir; marianum; enzymes; assays ENZYMES; ASSAYS"@en . . "Silybin is metabolized by cytochrome P4502C8 in vitro" . . "Silybin is metabolized by cytochrome P4502C8 in vitro"@en . . . . . . "0090-9556" . "US - Spojen\u00E9 st\u00E1ty americk\u00E9" . "Veinlichov\u00E1, Alena" . . "15310" . . "Anzenbacherov\u00E1, Eva" . "11" . "[1A4718096A5F]" . "Silybin is metabolized by cytochrome P4502C8 in vitro"@en . "RIV/61989592:15310/07:00004833" . "Jan\u010Dov\u00E1, Petra" . . "7"^^ .