Neuropeptide Y1 and Y5 receptor antagonists as potential anti-obesity drugs: Current status

Among the pharmacological strategies to treat obesity, two subtypes of the neuropeptide Y (NPY) receptor family have drawn the attention of several research groups in the effort to develop efficacious and safe anti-obesity drugs. In the last two decades, different classes of non-peptide compounds exhibiting significant anti-orexigenic responses in NPY knockout and NPY receptor deficient mice have been reported as NPY Y1 and Y5 receptor antagonists. At the beginning of this century, NPY receptor antagonists were considered promising anti-obesity compounds that modulate food intake and body weight in obese patients; however, only a few antagonists are currently being evaluated in clinical trials because there are other neuronal pathways that maintain homeostasis of food intake and body weight in animals, making the design of molecules with more affinity and selectivity for the NPY Y1 and Y5 receptors necessary. The present review is a compendium of the reports that account for the design, synthesis and biological evaluation of nonpeptide compounds that selectively bind to NPY Y1 and Y5 receptors. This review presents a historic retrospective of those antagonists that have shown a high affinity and selectivity for these two NPY receptors in preclinical and clinical trials, highlighting key structural features that display more affinity, selectivity, and better pharmacokinetic profiles.