Metabolism of Anandamide by Human Cytochrome P450 2J2 in the Reconstituted System and Human Intestinal Microsomes

Abstract

According to the Centers for Disease Control and Prevention, the incidence of inflammatory bowel diseases (IBD) is about 1 in 250 people in the United States. The disease is characterized by chronic or recurring inflammation of the gut. Because of the localization of the endocannabinoid system in the gastrointestinal tract, it may be a potential pharmacologic target for the treatment of IBD and other diseases. Fatty acid amide hydrolase (FAAH) is a potential candidate because it is upregulated in IBD. FAAH hydrolyzes and, as a consequence, inactivates anandamide (AEA), a prominent endocannabinoid. Inhibition of FAAH would lead to increases in the amount of AEA oxidized by cytochrome P450s (P450s). CYP2J2, the major P450 epoxygenase expressed in the heart, is also expressed in the intestine and has previously been reported to oxidize AEA. We have investigated the possibility that it may play a role in AEA metabolism in the gut and have demonstrated that purified human CYP2J2 metabolizes AEA to form the 20-hydroxyeicosatetraenoic acid ethanolamide (HETE-EA) and several epoxygenated products, including the 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acid ethanolamides (EET-EAs), in the reconstituted system. Kinetic studies suggest that the K M values for these products range from approximately 10 to 468 mM and the k cat values from 0.2 to 23.3 pmol/min per picomole of P450. Human intestinal microsomes, which express CYP2J2, metabolize AEA to give the 5,6-, 8,9-, and 11,12-EET-EAs, as well as 20-HETE-EA. Studies using specific P450 inhibitors suggest that although CYP2J2 metabolizes AEA, it is not the primary P450 responsible for AEA metabolism in human intestines.

Anti-inflammatory ω-3 endocannabinoid epoxides

“…3D). The total turnover rates of AEA, EPEA, and DHEA are significantly greater than those of AA, EPA, and DHA (28,32,56). Specifically, maximal CYP2J2 conversion of DHA to 19,20-EDP was calculated at 22.5 pmol·min −1 ·pmol −1 protein (57), whereas the CYP2J2 conversion of DHEA to 19,20-EDP-EA was 542.3 ± 44.6 5 pmol·min −1 ·pmol −1 protein, thus demonstrating that the preference for the DHEA substrate is an order of magnitude greater than the preference for DHA.…”

Inhibition and inactivation of human CYP2J2: Implications in cardiac pathophysiology and opportunities in cancer therapy

“…[31]. It was also shown that AA was a moderate inhibitor of CYP2J2-mediated metabolism of AEA [31]. The authors found that 5,6-EET-EA is a potent cannabinoid receptor-2 agonist.…”

“…CYP2J2 is an epoxygenase enzyme metabolizing a number of polyunsaturated omega-6 (ω-6) fatty acids such AA and LA and omega-3 (ω-3) fatty acids such as eicosapentaenoic acid (EPA) [20] and docosahexaenoic acid (DHA) [21]. [31]. It was also shown that AA was a moderate inhibitor of CYP2J2-mediated metabolism of AEA [31].…”

Endocannabinoid Virodhamine Is an Endogenous Inhibitor of Human Cardiovascular CYP2J2 Epoxygenase

“…9,17,20 Specifically, AEA and 2-AG interact with CYPs and undergo epoxidation to their more bioactive products, EET-EA and EET-G with varied biological activities. 16,20,24–26 These metabolites are targets of both FAAH and soluble epoxide hydrolase (sEH) which degrades CYP epoxygenase-derived eCB metabolites to yield the corresponding diol product, which is a current target for the development of anti-inflammatory drugs. 5,14,27,28 …”