The present study investigated the analgesic effect of a novel synthetic cyclohexanone derivative, 2,6-bis-4-(hydroxyl-3-methoxybenzilidine)-cyclohexanone or BHMC in a mouse model of chronic constriction injury-induced neuropathic pain. It was demonstrated that intraperitoneal administration of BHMC (0.03, 0.1, 0.3 and 1.0mg/kg) exhibited dose-dependent inhibition of chronic constriction injury-induced neuropathic pain in mice, when evaluated using Randall-Selitto mechanical analgesiometer. It was also demonstrated that pretreatment of naloxone (non-selective opioid receptor blocker), nor-binaltorphimine (nor-BNI, selective κ-opioid receptor blocker), but not β-funaltrexamine (β-FN, selective μ-opioid receptor blocker) and naltrindole hydrochloride (NTI, selective δ-opioid receptor blocker), reversed the anti-nociceptive effect of BHMC. In addition, the analgesic effect of BHMC was also reverted by pretreatment of 1H-[1,2,4]Oxadiazole[4,3-a]quinoxalin-1-one (ODQ, soluble guanosyl cyclase blocker) and glibenclamide (ATP-sensitive potassium channel blocker) but not Nω-nitro-l-arginine (l-NAME, a nitric oxide synthase blocker). Taken together, the present study demonstrated that the systemic administration of BHMC attenuated chronic constriction, injury-induced neuropathic pain. We also suggested that the possible mechanisms include κ-opioid receptor activation and nitric oxide-independent cyclic guanosine monophosphate activation of ATP-sensitive potassium channel opening.
We present a 35-year-old man with a preoperative diagnosis of a right lower lobe cystic mass. Misled by a radiological suggestion of an intraparenchymal lesion, he had a thoracotomy and right lower lobectomy. An intraoperative finding of a pedunculated cyst arising from the parietal pleural with subsequent histopathology confirmation of a benign bronchogenic cyst, however, would have made a less invasive surgical excision more appropriate.
The present study investigates the involvement of the l-arginine-Nitric Oxide-cGMP-K⁺ ATP pathways responsible for the action of anti-allodynic and antihyperalgesic activities of zerumbone in chronic constriction injury (CCI) induced neuropathic pain in mice. The role of l-arginine-NO-cGMP-K⁺ was assessed by the von Frey and the Randall-Selitto tests. Both allodynia and hyperalgesia assessments were carried out on the 14th day post CCI, 30 min after treatments were given for each respective pathway. Anti-allodynic and antihyperalgesic effects of zerumbone (10 mg/kg, i.p) were significantly reversed by the pre-treatment of l-arginine (10 mg/kg), 1H [1,2,4]Oxadiazole[4,3a]quinoxalin-1-one (ODQ), a soluble guanosyl cyclase blocker (2 mg/kg i.p.) and glibenclamide (ATP-sensitive potassium channel blocker) (10 mg/kg i.p.) (p < 0.05). Taken together, these results indicate that systemic administration of zerumbone produces significant anti-allodynic and antihyperalgesic activities in neuropathic pain in mice possibly due to involvement of the l-arginine-NO-cGMP-PKG-K⁺ ATP channel pathways in CCI model.