Melanocortins and Their Potential for the Treatment, Prevention and Amelioration of Complications of Diabetes

Diabetes mellitus (type I and II) is an advancing global health problem, concerningly increasing in prevalence in most of the developed and developing world. Current therapies, such as the subcutaneous injection of insulin, are invasive and require a close monitoring of blood glucose levels to prevent hypo- or hyperglycaemia from occurring. Despite an inexorable search for a cure since Banting and Best discovered and purified insulin in 1921, insulin remains a solitary insula, still the gold standard for treatment of type I and late-stage type II diabetes mellitus. Apropos of complications, diabetes causes a myriad of secondary maladies, ranging from diabetic kidney disease, diabetic retinopathy and diabetic neuropathy to erectile dysfunction and peripheral vascular disease. While scientists continue to interminably tinker with perfecting mechanical insulin pumps or dampening the immune response to pancreatic beta cells, an important aspect of the aetiology of diabetes should not be neglected, that of the metabolism. At its heart, diabetes can arguably be considered a metabolic disease, and this review suggests a return to focusing on preventing and treating diabetes by focussing on its metabolic causes. This narrative review summarises the potential of a recent class of synthetic peptides, the melanocortins, to help prevent and treat the complications of diabetes mellitus. The review summarises recent work showing the potential benefits of the melanocortins in treating diabetic complications through various pathways.