PTPN1 and type 2 diabetes mellitus: The aim of this review is to summarize some of the natural therapeutic strategies for prevention and control of T2DM, with a special emphasis on natural compounds that present pharmacological inhibitory activity against dipeptidyl peptidase-4 (DPP4), alpha-amylase, alpha-glucosidase, lipase, and protein tyrosine phosphatase 1B (PTP1B).