(±)14(15)-EET is a metabolite of arachidonic acid that is formed via epoxidation of arachidonic acid by cytochrome P450.[1],[2] It prevents increases in leukotriene B4, ICAM-1, and chemokine (C-C motif) ligand 1 (CCL2) induced by oxidized LDL in primary rat pulmonary artery endothelial cells (RPAECs) when used at a concentration of 1 μM.[3] (±)14(15)-EET induces dilation of preconstricted isolated canine coronary arterioles (EC50 = 0.2 pM).[4] It reduces myocardial infarct size as a percentage of the area at risk in a canine model of ischemia-reperfusion injury induced by left anterior descending coronary artery (LAD) occlusion when administered at a dose of 0.128 mg kg prior to occlusion or reperfusion.[5] Reference:[1]. Chacos, N., Falck, J.R., Wixtrom, C., et al. Novel epoxides formed during the liver cytochrome P-450 oxidation of arachidonic acid. Biochem. Biophys. Res. Commun. 104(3), 916-922 (1982).[2]. Oliw, E.H., Guengerich, F.P., and Oates, J.A. Oxygenation of arachidonic acid by hepatic monooxygenases. Isolation and metabolism of four epoxide intermediates. J. Biol. Chem. 257(7), 3771-3781 (1982).[3]. Jiang, J.-X., Zhang, S.-J., Xiong, Y.-K., et al. EETs attenuate ox-LDL-induced LTB4 production and activity by inhibiting p38 MAPK phosphorylation and 5-LO BLT1 receptor expression in rat pulmonary arterial endothelial cells. PLoS One 10(6), e0128278 (2015).[4]. Oltman, C.L., Weintraub, N.L., VanRollins, M., et al. Epoxyeicosatrienoic acids and dihydroxyeicosatrienoic acids are potent vasodilators in the canine coronary microcirculation. Circ. Res. 83(9), 932-939 (1998).[5]. Nithipatikom, K., Moore, J.M., Isbell, M.A., et al. Epoxyeicosatrienoic acids in cardioprotection: Ischemic versus reperfusion injury. Am. J. Physiol. Heart Circ. Physiol. 291(2), H537-H542 (2006).
N-Desbutyl dronedarone is an active metabolite of the antiarrhythmic agent dronedarone .1,2,3It is formed from dronedarone by cytochrome P450s (CYPs) and monoamine oxidase (MAO) in human hepatocyte preparations.4N-Desbutyl dronedarone inhibits the binding of 3,3’,5-triiodo-L-thyronine to the thyroid hormone receptors TRα1and TRβ1(IC50s = 59 and 280 μM for the chicken and human receptors, respectively).1It inhibits CYP2J2-mediated formation of 14,15-EET from arachidonic acid and soluble epoxide hydrolase-mediated formation of 14,15-DHET from 14,15-EET (IC50s = 1.59 and 2.73 μM, respectively, in cell-free assays).2N-Desbutyl dronedarone decreases intracellular ATP levels in H9c2 rat cardiomyocytes (IC50= 1.07 μM) and inhibits mitochondrial complex I, also known as NADH dehydrogenase, and mitochondrial complex II, also known as succinate dehydrogenase, activities in isolated rat heart mitochondria (IC50s = 11.94 and 24.54 μM, respectively).3 1.Van Beeren, H.C., Jong, W.M.C., Kaptein, E., et al.Dronerarone acts as a selective inhibitor of 3,5,3’-triiodothyronine binding to thyroid hormone receptor-α1: in vitro and in vivo evidenceEndocrinology144(2)552-558(2003) 2.Karkhanis, A., Tram, N.D.T., and Chan, E.C.Y.Effects of dronedarone, amiodarone and their active metabolites on sequential metabolism of arachidonic acid to epoxyeicosatrienoic and dihydroxyeicosatrienoic acidsBiochem. Pharmacol.146188-198(2017) 3.Karkhanis, A., Leow, J.W.H., Hagen, T., et al.Dronedarone-induced cardiac mitochondrial dysfunction and its mitigation by epoxyeicosatrienoic acidsToxicol. Sci.163(1)79-91(2018) 4.Klieber, S., Arabeyre-Fabre, C., Moliner, P., et al.Identification of metabolic pathways and enzyme systems involved in the in vitro human hepatic metabolism of dronedarone, a potent new oral antiarrhythmic drugPharmacol. Res. Perspec.2(3)e00044(2014)