TY - JOUR T1 - Human CYP2S1 Metabolizes Cyclooxygenase- and Lipoxygenase-Derived Eicosanoids JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 180 LP - 190 DO - 10.1124/dmd.110.035121 VL - 39 IS - 2 AU - Peter Bui AU - Satoshi Imaizumi AU - Sudheer Reddy Beedanagari AU - Srinivasa T. Reddy AU - Oliver Hankinson Y1 - 2011/02/01 UR - http://dmd.aspetjournals.org/content/39/2/180.abstract N2 - CYP2S1 is a recently described dioxin-inducible cytochrome P450. We previously demonstrated that human CYP2S1 oxidizes a number of carcinogens but only via the peroxide shunt. In this article, we investigated whether human CYP2S1 can metabolize cyclooxygenase- and lipoxygenase-derived lipid peroxides in a NADPH-independent fashion. Human CYP2S1 metabolizes prostaglandin G2 (PGG2) (Km = 0.267 ± 0.072 μM) into several products including 12S-hydroxy-5Z,8E,10E-heptadecatrienoic acid (12-HHT). It also metabolizes prostaglandin H2 (PGH2) (Km = 11.7 ± 2.8 μM) into malondialdehyde, 12-HHT, and thromboxane A2 (TXA2). The turnover to 12-HHT by human CYP2S1 (1.59 ± 0.04 min−1) is 40-fold higher than that of TXA2 (0.04 min−1). In addition to PGG2 and PGH2 metabolism, human CYP2S1 efficiently metabolizes the hydroperoxyeicosatetraenoic acids (5S-, 12S-, and 15S-) and 13S-hydroperoxyoctadecadienoic acid into 5-oxo-eicosatetraenoic acid (turnover = 16.7 ± 0.3 min−1), 12-oxo-eicosatetraenoic acid 1 (11.5 ± 0.9 min−1), 15-oxo-eicosatetraenoic acid (16.9 ± 0.8 min−1), and 13-octadecadienoic acid (20.2 ± 0.9 min−1), respectively. Other cytochromes P450 such as CYP1A1, 1A2, 1B1, and 3A4 underwent similar conversions but at slower rates. The fatty acid hydroperoxides were also converted by human CYP2S1 to several epoxyalcohols. Our data indicate that fatty acid endoperoxides and hydroperoxides represent endogenous substrates of CYP2S1 and suggest that the enzyme CYP2S1 may play an important role in the inflammatory process because some of the products that CYP2S1 produces play important roles in inflammation. ER -