Abstract

Obesity and insulin resistance are major risk factors for a number of metabolic disorders, such as type 2 diabetes mellitus^{1, 2}. Insulin has been suggested to function as one of the adiposity signals to the brain for modulation of energy balance. Administration of insulin into the brain reduces food intake and body weight^{3, 4, 5}, and mice with a genetic deletion of neuronal insulin receptors are hyperphagic and obese⁶. However, insulin is also an anabolic factor; when administered systemically, pharmacological levels of insulin are associated with body weight gain in patients⁷. In this study, we investigated the efficacy and feasibility of small molecule insulin mimetic compounds^{8, 9} to regulate key parameters of energy homeostasis. Central intracerebroventricular (i.c.v.) administration of an insulin mimetic resulted in a dose-dependent reduction of food intake and body weight in rats, and altered the expression of hypothalamic genes known to regulate food intake and body weight. Oral administration of a mimetic in a mouse model of high-fat diet-induced obesity reduced body weight gain, adiposity and insulin resistance. Thus, insulin mimetics have a unique advantage over insulin in the control of body weight and hold potential as a novel anti-obesity treatment.