Identification of antihypertensive peptides from mung bean protein hydrolysate and their effects in spontaneously hypertensive rats

Defatted mung bean meal was hydrolyzed with bromelain to obtain MPH, which was fractionated into different peptide fractions (<1 kDa, 1–5 kDa, 5–10 kDa, >10 kDa) using membrane ultrafiltration. The <1 kDa was the most active inhibitor of angiotensin converting enzyme (ACE) and renin. Five peptides (LPRL, YADLVE, LRLESF, HLNVVHEN, and PGSGCAGTDL) identified from the <1 kDa fraction were studied for antihypertensive effects in comparison to the MPH. Results showed that LRLESF was the most potent inhibitor of ACE (IC 50  = 5.4 µM) while LPRL was the weakest (IC 50  = 1912 µM). In contrast, YADLVE was the strongest renin inhibitor with 97% inhibition while LRLESF was the weakest (~30%). Oral administration to spontaneously hypertensive rats revealed strong blood pressure reductions with up to −36 mmHg when compared to −15 mmHg for MPH. However, YADLVE had the most persistent effect after 24 h while PGSGCAGTDL had the least.