STUDIES IN VITRO INHIBITION OF THE ANGIOTENSIN-CONVERTING ENZYME-I, HYPOTENSIVE AND ANTIHYPERTENSIVE EFFECTS OF PEPTIDE FRACTIONS OF V. UNGUICULATA

Inhibition of angiotensin-converting enzyme I (ACE-I) in vitro and in vivo from peptide fractions by enzymatic hydrolysis of the Vigna unguiculata protein concentrate was evaluated. Hydrolysis was done with Pepsin-Pancreatin and Flavourzima (R) in two separate systems. The resulting hidrolysates were ultrafiltrated to obtain fractions with different molecular weight. The fractions with better inhibition Flavourzima (R) were size > 1 kDa (> 1 kDa-F) and < 1 kDa (< 1 kDa-F), with an IC50 of 1222.84 and 1098.6 mu g/ml respectively. Pepsin-Pancreatin fraction <1 kDa (<1 kDa-PP) showed the best activity with an IC50 of 402.23 mu g/ml. Hypotensive effect was evaluated in a normotensive model for 4 weeks, 10 mg/kg (weight)/orally, in Wistar rats. < 1 kDa-F decreased systolic: diastolic in 8.61: 14.09% respectively, while in the case of <1 kDa-PP lowed diastolic pressure in 14.15%. Antihypertensive effect was evaluated in induced model for 3 weeks with L-NAME (25 mg/kg (weight)/day). In the next 4 weeks peptide fractions, were administered, noticing >1 kDa-F decreased systolic pressure and diastolic 10.27: 4.92% respectively, while <1 kDa-F decreased diastolic pressure 3.56%. <1 kDa-PP decreased systolic: diastolic in 15.98: 17.12%, respectively.