Soluble epoxide hydrolase inhibition alleviates chemotherapy induced neuropathic pain

Inhibitory Activity of Glycosides from Elsholtzia ciliata against Soluble Epoxide Hydrolase and Cytokines in RAW264.7 Cells

Soluble epoxide hydrolase (sEH) and pro-inflammatory cytokines are associated with the development of inhibitors for cardiovascular and inflammatory diseases. Here, we report on four natural sEH inhibitors isolated from the aerial parts of Elsholtzia ciliata (Thunb.) Hyl.. The four compounds, 1-4, were identified as luteolin-7-O-glucoside (1), yuanhuanin (2), apigenin-7-O-glucoside (3), and butein-4'-O-glucoside (4). Among them, compounds 2 and 4 are reported for the first time from this plant. In vitro and in silico, they showed inhibitory activity towards sEH at micromole concentrations. Moreover, they suppressed pro-inflammatory cytokines in polyinosinic:polycytidylic acid (poly(I:C))-stimulated RAW264.7 cells. Notably, 4 significantly downregulated the sEH catalytic reaction, NO and PGE2 production, and the expression levels of iNOS, COX-2, IL-6 mRNA, and sEH mRNA. Therefore, butein-4'-O-glucoside (4) is a potential sEH inhibitor that may be suitable for treating inflammation and cardiovascular diseases caused by infection.

Randomized, double-blind, phase 1a single-ascending dose and food effect studies assessing safety and pharmacokinetics of EC5026 in healthy volunteers

Chronic pain represents a significant unmet medical need, affecting one-fifth of the U.S. population. EC5026 is a small molecule inhibitor of the enzyme soluble epoxide hydrolase (sEH) which is being developed as a novel non-opioid, non-NSAID analgesic. EC5026 prolongs the action of epoxy fatty acids, endogenous analgesic lipid mediators that are rapidly metabolized by sEH. We evaluated the safety and pharmacokinetic profile of EC5026 in two phase I trials, a single-ascending dose (SAD) study and a fed-fasted study. The SAD study evaluated EC5026 doses ranging from 0.5 to 24 mg in healthy volunteers. EC5026 was well tolerated. No treatment-emergent adverse events were considered related to EC5026. No apparent treatment- or dose-related trends in laboratory results, vital signs, physical examinations, or electrocardiograms were observed. A linear, near-dose-proportional increase in exposure was observed with progressive doses in the SAD study; plasma exposure was below or near the lower limit of quantification after 0.5-2 mg doses. Mean half-lives ranged from 41.8 to 59.1 h. for doses of 8-24 mg, supporting a once-daily dosing regimen. In the fed-fasted study using 8 mg EC5026 tablets, higher peak concentrations (66%) and total exposures (53%) were observed under the fed condition. Plasma concentrations declined in a monoexponential manner with mean half-lives of 59.5 h. in the fed state and 66.9 h. in the fasted state. Future clinical trials using EC5026 for the treatment of pain are justified based on the favorable outcomes from both clinical trials along with preclinical evidence of analgesic activity.

Role of soluble epoxide hydrolase in pain and depression comorbidity

The coexistence of chronic pain and depression in clinical practice places a substantial social burden and profoundly impacts in patients. Although a clear correlation exists, the underlying mechanism of comorbidity between chronic pain and depression remains elusive. Research conducted in recent decades has uncovered that soluble epoxide hydrolase, a pivotal enzyme in the metabolism of polyunsaturated fatty acids, plays a crucial role in inflammation. Interestingly, this enzyme is intricately linked to the development of both pain and depression. With this understanding, this review aims to summarize the roles of soluble epoxide hydrolase in pain, depression, and their comorbidity. Simultaneously, we will also explore the underlying mechanisms, providing guidance for future research and drug development.