Structure-Directed Discovery of Potent Soluble Epoxide Hydrolase Inhibitors for the Treatment of Inflammatory Diseases

Discovery of a novel lead characterized by a stilbene-extended scaffold against sepsis as soluble epoxide hydrolase inhibitors

Recently, some inhibitors of soluble epoxide hydrolase (sEH) showed limited potential in treating sepsis by increasing survival time, but they have unfortunately failed to improve survival rates. In this study, we initially identified a new hit 11D, belonging to a natural skeleton known as stilbene and having an IC50 of 644 nM on inhibiting murine sEH. Natural scaffold-based sEH inhibitors are paid less attention. A combination of structure-activity relationships (SARs)-guided structural optimization and computer-aided skeleton growth led to a highly effective lead compound 70P (IC50: 4.0 nM). The dose-response study indicated that 70P (at doses of 0.5-5 mg/kg, ip.) significantly increased survival rates and survival time by reducing the levels of the inflammatory factors TNF-α and IL-6 in the liver. Interestingly, 70P exhibited much higher accumulation in the liver than in plasma (AUC ratio: 175). In addition, 70P exhibits equal IC50 value (1.5 nM) on inhibiting human sEH as EC5026 (1.7 nM). In conclusion, the natural scaffold-extended sEH inhibitor 70P has the potential to become a new promising lead for addressing the unmet medical need in sepsis treatment, which highlighted the importance of natural skeleton in developing sEH inhibitors.

Design and Synthesis of Dual-Targeting Inhibitors of sEH and HDAC6 for the Treatment of Neuropathic Pain and Lipopolysaccharide-Induced Mortality

Epoxyeicosatrienoic acids with anti-inflammatory effects are inactivated by soluble epoxide hydrolase (sEH). Both sEH and histone deacetylase 6 (HDAC6) inhibitors are being developed as neuropathic pain relieving agents. Based on the structural similarity, we designed a new group of compounds with inhibition of both HDAC6 and sEH and obtained compound M9. M9 exhibits selective inhibition of HDAC6 over class I HDACs in cells. M9 shows good microsomal stability, moderate plasma protein binding rate, and oral bioavailability. M9 exhibited a strong analgesic effect in vivo, and its analgesic tolerance was better than gabapentin. M9 improved the survival time of mice treated with lipopolysaccharide (LPS) and reversed the levels of inflammatory factors induced by LPS in mouse plasma. M9 represents the first sEH/HDAC6 dual inhibitors with in vivo antineuropathic pain and anti-inflammation.

Integrated transcriptomics and metabolomics reveal the toxic mechanisms of mercury exposure to an endangered species Tachypleus tridentatus

Mercury (Hg) pollution is threatening the health of endangered Tachypleus tridentatus whereas the toxic mechanism is still unclear. This study combined transcriptomic and metabolomics technology to reveal the toxic mechanisms of mercury (Hg 2+, 0.025 mg/L) exposing to T. tridentatus larvae for 15 days. Mercury induced cellular toxicity and cardiovascular dysfunction by dysregulating the genes related to endocrine system, such as polyubiquitin-A, cathepsin B, atrial natriuretic peptide, etc. Mercury induced lipid metabolic disorder with the abnormal increase of lysoPC, leukotriene D4, and prostaglandin E2. Cytochrome P450 pathway was activated to produce anti-inflammatory substances to reconstruct the homeostasis. Mercury also inhibited arginine generation, which may affect the development of T. tridentatus by disrupting the crucial signaling pathway. The mercury methylation caused enhancement of S-adenosylmethionine to meet the need of methyl donor. The mechanisms described in present study provide new insight into the risk assessment of mercury exposure to T. tridentatus.