Bovine lactoferrin-derived ACE inhibitory tripeptide LRP also shows antioxidative and anti-inflammatory activities in endothelial cells

The pathophysiology of hypertension involves the interplay among renin-angiotensin system (RAS), oxidative stress and inflammation. Our previous computational study has indicated potent ACE inhibitory peptides could be released from bovine lactoferrin with the digestion of thermolysin. The objectives of this study were to characterize ACE inhibitory peptides from bovine lactoferrin and to explore their potential antioxidative and anti-inflammatory activities. Bovine lactoferrin hydrolysate digested by thermolysin showed an IC50 value of 31.0 ± 1.1 µg/mL, which was not affected by further pepsin and trypsin digestion. Following HPLC fractionation, 8 peptides were identified and LRP (IC50 = 1.2 ± 0.05 µM) showed the highest ACE inhibitory activity. LRP (50 µM) significantly inhibited tumor necrosis factor-alpha (TNF-α)-stimulated inflammation in endothelial cells. LRP (20 and 50 µM) also significantly reduced superoxide level in basal oxidation test. The results indicated that ACE inhibitory tripeptide LRP also showed antioxidative and anti-inflammatory activities, suggesting its potential application against hypertension.