DPP4 and type 2 diabetes mellitus: Bioactive peptides derived from plant sources can reduce levels of hypertension and type 2 diabetes mellitus because these peptides can inhibit the activity of angiotensin-converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV), whose activity is closely related to the development of hypertension and blood glucose accumulation (Cian et al., 2019; Li et al., 2019; Pugliese et al., 2019; Suárez and Añón, 2019; Ying et al., 2021).