The mechanisms underlying the anti-inflammatory and anti-hypertensive effects of long chain ω-3 polyunsaturated fatty acids (PUFAs) are still unclear. The epoxides of an ω-6 fatty acid, arachidonic acid (epoxyeicosatrienoic acids; EETs) also exhibit anti-hypertensive and anti-inflammatory effects. Thus, we hypothesized that the major ω-3 PUFAs including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may lower blood pressure and attenuate renal markers of inflammation through their epoxide metabolites. Here, we supplemented mice with an ω-3 rich diet for three weeks in a murine model of angiotensin-II dependent hypertension. Also, since EPA and DHA epoxides are metabolized by soluble epoxide hydrolase (sEH), we tested the combination of a sEH inhibitor and the ω-3 rich diet. Our results show that ω-3 rich diet in combination with the sEH inhibitor lowered Ang-II increased blood pressure, further increased renal levels of EPA and DHA epoxides, reduced renal markers of inflammation (i.e. prostaglandins and MCP-1), down-regulated an epithelial sodium channel and up-regulated Angiotensin converting enzyme-2 message (ACE-2) and significantly modulated cyclooxygenase and lipoxygenase metabolic pathways. Overall, our findings suggest that epoxides of the ω-3 PUFAs contribute to lowering SBP and attenuating inflammation in part by reduced prostaglandins and MCP-1 and by up-regulation of ACE-2 in angiotensin-II dependent hypertension.

Mediators of anti-hypertensive actions of docosahexaenoic acid (DHA) are largely unknown. The omega-3 epoxide of DHA, 19, 20-EDP (epoxydocosapentaenoic acid) is metabolized by soluble epoxide hydrolase (sEH), which also metabolizes the anti-inflammatory and anti-hypertensive arachidonic acid (ARA) epoxides, EETs (epoxyeicosatrienoic acids). Based in part on plasma levels of EDPs following a DHA-rich diet, we hypothesized that 19, 20-EDP contributes to the anti-hypertensive actions of DHA in angiotensin-II dependent hypertension. Treatment individually with 19, 20-EDP, and a potent sEH inhibitor (sEHI) TPPU (1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea) significantly lowered blood pressure (BP) as compared to angiotensin-II infused animals. The largest reduction in BP was obtained with the combination of 19, 20-EDP and TPPU, which was more efficacious than the combination of 14, 15-EET and TPPU. Oxylipin profiling revealed that 19, 20-EDP and 14, 15-EET infusion affected mostly metabolites of the P450 pathway but also renal levels of prostaglandin-E2. Our findings suggest that 19, 20- EDP is a mediator of the anti-hypertensive effects of DHA in angiotensin-II dependent hypertension. It appears that 19, 20- EDP requires metabolic stabilization with a sEHI to be most effective in lowering BP, although both TPPU and 19, 20- EDP are so effective on their own that demonstrating additive or synergistic interactions is difficult.

BACKGROUND AND PURPOSESoluble epoxide hydrolase inhibitors (sEHIs) possess anti-inflammatory, antiatherosclerotic, antihypertensive and analgesic properties. The pharmacokinetics (PK) and pharmacodynamics in terms of inhibitory potency of sEHIs were assessed in non-human primates (NHPs). Development of a sEHI for use in NHPs will facilitate investigations on the role of sEH in numerous chronic inflammatory conditions. EXPERIMENTAL APPROACHPK parameters of 11 sEHIs in cynomolgus monkeys were determined after oral dosing with 0.3 mg·kg -1. Their physical properties and inhibitory potency in hepatic cytosol of cynomolgus monkeys were examined. Dose-dependent effects of the two inhibitors 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) and the related acetyl piperidine derivative, 1-trifluoromethoxyphenyl-3-(1-acetylpiperidin-4-yl) urea (TPAU), on natural blood eicosanoids, were determined. KEY RESULTSAmong the inhibitors tested, TPPU and two 4-(cyclohexyloxy) benzoic acid urea sEHIs displayed high plasma concentrations (>10 ¥ IC50), when dosed orally at 0.3 mg·kg -1. Although the 4-(cyclohexyloxy) benzoic acid ureas were more potent against monkey sEH than piperidyl ureas (TPAU and TPPU), the latter compounds showed higher plasma concentrations and more drug-like properties. The Cmax increased with dose from 0.3 to 3 mg·kg -1 for TPPU and from 0.1 to 3 mg·kg -1 for TPAU, although it was not linear over this range of doses. As an indication of target engagement, ratios of linoleate epoxides to diols increased with TPPU administration. CONCLUSION AND IMPLICATIONSOur data indicate that TPPU is suitable for investigating sEH biology and the role of epoxide-containing lipids in modulating inflammatory diseases in NHPs. Abbreviations

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Fine‐tuning than complete disruption of 2‐arachidonoylglycerol (2‐AG) metabolism in the brain represents a promising pharmacological approach to limit potential untoward effects associated with complete blockade of monoacylglycerol lipase (MGL), the primary hydrolase of 2‐AG. This could be achieved through a/b‐hydrolase domain containing 6 (ABHD6) inhibition, which will provide a smaller and safer contribution to 2‐AG regulation in the brain. Pharmacological studies with ABHD6 inhibitors have recently been reported, where modulation of ABHD6 activity either through CB1R‐dependent or CB1R‐independent processes showed promise in preclinical models of epilepsy, neuropathic pain and inflammation. Furthermore in the periphery, ABHD6 modulates 2‐AG and other fatty acid monoacylglycerols (MAGs) and is implicated in Type‐2 diabetes, metabolic syndrome and potentially other diseases. Herein, we report the discovery of single‐digit nanomolar potent and highly specific ABHD6 inhibitors with >1000‐fold selectivity against MGL and FAAH. The new ABHD6 inhibitors provide early leads to develop therapeutics for neuroprotection and the treatment of inflammation and diabetes.