Neuropeptides B, S and W, Obestatin/Ghrelin-Associated Peptide, and Others: Really New Feeding Regulatory Peptides?

The last 20 years of the twentieth century witnessed a dramatic increase in research aimed at determining the mechanisms that regulate feeding behavior. Researchers, prompted by the alarming increase in the prevalence of obesity have identified many brain neuropeptides, especially in the hypothalamus that promote or inhibit food intake. How the complex interactions of these peptides leads to obesity has been clarified somewhat; unfortunately, this has not led to major advances in anti-obesity drug discovery. Continued effort during the first years of the new millennium has led to the discovery of new peptides mainly through inverse pharmacology techniques. In this article, we update information on obestatin, a closely related companion of ghrelin, on neuropeptide S, neuropeptide W, and others. These peptides use both classical and independent regulatory pathways to modulate feeding but often have additional biological activities. Strong arguments support a role in feeding regulation for some peptides. For others, this role remains controversial and further research is needed to clarify their exact effects.