Angiotensin I-Converting Enzyme (ACE) Inhibitory Activity of Peptides Isolated from Carabao Mango (Mangifera indica) Flesh

Abstract

Hypertension has been reported as the second major cause of morbidity in the Philippines. One of the mechanisms to control blood pressure is through the inhibition of the angiotensin I-converting enzyme (ACE). This study specifically focused on the determination of ACE inhibitory activities of peptides from ‘Carabao’ mango flesh of three shell colors (SC1, SC3, SC5). The bioactive peptides were obtained upon a series of extraction, purification, and enzymatic hydrolysis steps. Among the undigested and digested crude and purified samples, the highest in vitro ACE inhibition was exhibited by the three-hour digest of SC3 (83.28 ± 0.83%). The most prominent peak from the fractionation of the mixture of peptides in SC3 digest was evaluated for ACE inhibition, and the decrease in activity inferred the synergistic effect of the peptides in exhibiting the inhibitory function. This selected bioactive peptide was revealed to have alanine and phenylalanine as the components, which can possibly be AF – an ACE inhibitory peptide determined from in silico analyses. Meanwhile, assessment of the in vivo antihypertensive activity showed no significant results due to insufficiently administered doses of the samples. Overall, the measured activity of the ACE inhibitory peptides inferred the potential of mango as a functional food in dealing with hypertension.