DPP4 and metabolic disease: These peptides are bioactive compounds with diverse physiological functions, exhibiting a wide range of inhibitory activities against various enzymes, like inhibiting angiotensin-converting enzyme (ACE), renin, dipeptidyl peptidase-IV (DPP-IV) and peptidases, with significant potential for therapeutic applications in managing hypertension, metabolic disorders, neurodegenerative and inflammatory disorders [51,52,53,54].