Rimonabant, a cannabinoid CB₁ receptor antagonist, attenuates mechanical allodynia and counteracts oxidative stress and nerve growth factor deficit in diabetic mice

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• 作者：Francesca Comelli ; Isabella Bettoni ; Anita Colombo ; Pietro Fumagalli ; Gabriella Giagnoni ; Barbara Costa
• 关键词：Cannabinoid ; Diabetes ; Nerve growth factor ; Neuropathy ; Pain ; Rimonabant
• 刊名：European Journal of Pharmacology
• 出版年：2010
• 出版时间：10 July 2010
• 年：2010
• 卷：637
• 期：1-3
• 页码：62-69
• 全文大小：458 K

文摘

Diabetes is one of the leading causes of painful neuropathy and to date, besides a tight glycemic control, a viable treatment for this complication is not available. Rimonabant is a selective cannabinoid CB₁ receptor antagonist that produces a significant increase in insulin sensitivity and a reduction of HbA_1c in diabetic patients. This study aimed to investigate the therapeutic potential of rimonabant in relieving diabetes-induced neuropathic pain. The repeated treatment with rimonabant evoked a significant attenuation of mechanical allodynia in diabetic mice that was dose- and time-dependent. This effect occurred without alteration of hyperglycemia, but it was associated with significant effects on many key players in the pathogenesis of diabetic neuropathy. Metabolic changes induced by hyperglycemia lead to oxidative stress, deregulation of cytokine control and reduced production and transport of nerve growth factor (NGF), and all these factors contribute to neuropathic pain. Rimonabant treatment reduced oxidative stress in peripheral nerve, as revealed by the ability of the compound to counteract the reduced glutathione (GSH) depletion. The same repeated treatment inhibited tumor necrosis factor (TNFα) overproduction in the spinal cord and increased the NGF support. This rimonabant-induced improvement might favour the nerve regeneration; accordingly, the histological analysis of sciatic nerves showed a marked degeneration of myelinated fibers in diabetic mice, that was substantially reduced after rimonabant administration. These findings support the hypothesis that CB₁ antagonists would represent a new opportunity for diabetic patients, since currently there are no treatments for painful diabetic neuropathy other than treating the diabetic condition per se.