Antidiabetic and Anti-Obesity Agents

GIP (Glucose-dependent Insulinotropic Polypeptide) is released from K-cells in the duodenum, and GLP-1 (Glucagon-Like Peptide-1) is secreted by L-cells in the ileum and colon; both are incretins—gut-derived peptides that enhance insulin secretion from pancreatic beta cells in a glucose-dependent manner, helping regulate blood sugar without causing excessive hypoglycemia. Glucagon, produced by pancreatic alpha cells, is a gut–pancreatic hormone that stimulates the liver to release stored glucose, promotes lipid metabolism, and increases energy expenditure. The secretion of GIP and GLP-1 is influenced by the gut microbiota, whose metabolites can stimulate these enteroendocrine cells, thereby indirectly affecting glucose metabolism and appetite regulation. Together, these hormones coordinate pancreatic hormone release and hepatic metabolism, forming the basis for advanced multi-agonist drugs designed to improve glycemic control, promote weight loss, and boost metabolic activity.