Cytoprotection by melatonin: The metabolic syndrome as an example

Abstract

Abstract: As for metabolic syndrome (MS), several risk factors for cardiovascular disease are known, including elevated blood pressure, hyperinsulinemia, glucose intolerance, and dyslipidemia. We hereby discussed the special role that the chronobiotic/cytoprotective properties of melatonin may have in prevention and treatment of MS. Melatonin levels are consistently reduced in MS. The therapeutic potential of melatonin includes improvement of sleep efficiency and antioxidant and anti-inflammatory properties that derive partly from its role as a metabolic regulator and mitochondrial protector. This article analyzes the actions of melatonin that are relevant to the attenuation of inflammatory responses in MS and how melatonin is effective to curtail MS in animal models of hyperadiposity and ischemic and nonischemic heart failure. The clinical data supporting the therapeutical use of melatonin in human MS are also reviewed. From animal studies the cytoprotective effects of melatonin need high doses to become apparent (i.e., in the 40–100 mg/day range). The off-label use of melatonin is finally discussed.