Anti-inflammatory effects of 7-hydroxyl-1-methylindole-3-acetonitrile, a synthetic arvelexin derivative, on the macrophages through destabilizing mPGES-1 mRNA and suppressing NF-κB activation.

Abstract We previously demonstrated that 7-hydroxyl-1-methylindole-3-acetonitrile (7-HMIA), a synthesized analog of arvelexin, showed the strong inhibitory effects on LPS-induced NO and PGE 2 production in macrophages. In this study, we focused on elucidating the anti-inflammatory properties of 7-HMIA and the mechanisms involved using in vitro and in vivo experimental models. In LPS-induced RAW 264.7 macrophages, 7-HMIA significantly inhibited the release of proinflammatory mediators such as prostaglandin E 2 (PGE 2 ), nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6). We also found that 7-HMIA suppressed PGE 2 production not by inhibiting cyclooxygenase-2 (COX-2) expression or activity, but rather by suppressing the mRNA stability of microsomal prostaglandin E synthase (mPGES-1). Furthermore, 7-HMIA mediated attenuation of inducible NO synthase (iNOS), TNF-α, and IL-6 was closely associated with suppression of transcriptional activities of nuclear factor-kappa B (NF-κB), by decreasing p65 nuclear translocation and Akt phosphorylation. Animal studies revealed that 7-HMIA potently suppressed the carrageenan-induced paw edema and myeloperoxidase (MPO) activity in paw tissues. Taken together, our data indicated that the molecular basis for the anti-inflammatory properties of 7-HMIA involved the inhibition of mRNA stability of mPGES-1 and PI3K/Akt-mediated NF-κB pathways.