In vitro study on novel bioactive peptides with antioxidant and antihypertensive properties from edible rhizomes

Abstract

© 2020 Elsevier Ltd Rhizome proteins of white turmeric, turmeric and ginger were hydrolyzed using pepsin and trypsin. The peptides from crude hydrolysates were purified based on antihypertensive and antioxidant activities. The peptide sequences were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The binding energy with ACE of each antihypertensive peptides was predicted by in silico docking. Among the 11 bioactive peptides selected from the three rhizomes, five peptides from ginger harbored both antioxidant and anti-ACE activities. Particularly potent was the VTYM peptide from ginger, with the lowest IC50 and EC50 values of 16.4 ± 0.4 μmol/L, 19.9 ± 2.1 μmol/L and 24.0 ± 3.7 μmol/L in antihypertensive, DPPH, and ABTS assays, respectively. In addition, VTYM was capable of protecting Agrobacterium tumefaciens sodBI sodBII sodBIII triple mutant against menadione treatment. Among turmeric-derived peptides, CGVGAA, DVDP, and CACGGV exhibited strong anti-hypertensive activities, with IC50 values of 18.3 ± 0.1 μmol/L, 19.0 ± 0.6 μmol/L and 25.0 ± 0.2 μmol/L, respectively. Hence, this study demonstrates that many edible rhizomes, apart from serving as valuable sources of essential oil and bioactive metabolites, are also bountiful sources of bioactive peptides that can be harnessed for the benefits of human health.