anomalin and Acute-Disease

The numerous mediators of pain and inflammation are products of injury-induced gene expression that lead to changes in the nervous system and immune responses. These multiple molecules and mechanisms suggest novel strategies that could be used for analgesic drug development. The present study investigated the possible anti-hyperalgesic effects of anomalin in complete Freund's adjuvant (CFA)-induced acute and chronic inflammatory pain models. Acute pretreatment of mice with anomalin (10 and 50mg/kg, i.p.) produced a significant anti-nociceptive effect against CFA- and carrageenan-induced mechanical hyperalgesia and allodynia. In a chronic pain model, administration of anomalin inhibited CFA-induced hyperalgesia, and it did not cause any apparent toxicity. Another set of experiments observed that anomalin inhibited CFA- and carrageenan-induced paw edema in acute and chronic models. To elucidate the molecular mechanism underlying the anti-nociceptive effect of anomalin, the various pain signaling pathways [NF-κB, cAMP response element-binding protein (CREB), and mitogen activated protein kinase (MAPKs)/AP-1] that are involved were examined. Intraperitoneal (i.p.) pretreatment of anomalin exhibited potent inhibitory effects on direct mediators of hyperalgesia (iNOS and COX-2). The release of CFA-induced plasma nitrite and paw tissue hyperalgesic cytokine (TNF-α) was reduced remarkably. In addition, the adenosine 5'-triphosphate (ATP) in plasma and substance P (SP) in paw tissue were markedly suppressed by anomalin. These results demonstrate that anomalin exhibits an analgesic effect in a consistent manner and that its mechanisms involve the inhibition of the NF-κB, CREB, and MAPKs/AP-1 signaling pathways.

Topics: Acute Disease; Adenosine Triphosphate; Analgesics; Animals; Chronic Disease; Coumarins; Cyclic AMP Response Element-Binding Protein; Cyclooxygenase 2; Disease Models, Animal; Gene Expression Regulation, Enzymologic; Hyperalgesia; Inflammation; Liver; Male; Mice; Mitogen-Activated Protein Kinases; NF-kappa B; Nitric Oxide Synthase Type II; Nitrites; Pain; Signal Transduction; Substance P; Time Factors; Tumor Necrosis Factor-alpha