Research Progress on Marine Natural Products for Diabetes: From Mechanistic Insights to Compound Exploration

Marine natural products, derived from marine organisms, include small molecular compounds (such as terpenoids, alkaloids, carotenoids, phenols, and butyrolactones) as well as macromolecular compounds (such as polysaccharides and peptides), exhibiting highly diverse chemical structures. These compounds have demonstrated significant efficacy in the treatment of diabetes. Terpenoids exert hypoglycemic effects by inhibiting enzymes such as α-glucosidase and protein tyrosine phosphatase 1B (PTP1B). Alkaloids modulate pathways including PPARγ and AMPK. Carotenoids act by inhibiting α-glucosidase, upregulating AMPK, or enhancing GLUT4 expression. Phenols suppress enzymes such as α-amylase, α-glucosidase, and PTP1B. Butyrolactones stimulate insulin secretion and regulate signaling pathways. Macromolecular polysaccharides can inhibit digestive enzymes or modulate glucose transporters, while peptides inhibit DPP-IV to exert antidiabetic effects. This review comprehensively summarizes the structural diversity, antidiabetic mechanisms, and related research findings of various marine natural products, highlighting their potential in combating diabetes. It is expected to provide a rich source for the development of novel, highly effective, and low side-effect antidiabetic drugs.