Antioxidant properties, ACE/renin inhibitory activities of pigeon pea hydrolysates and effects on systolic blood pressure of spontaneously hypertensive rats

Abstract

Legumes are rich sources of protein in human diet and their consumption has been associated with the prevention of chronic diseases attributable to their bioactive components. Pigeon pea (Cajanus cajan) is an underutilized legume with relatively high protein content (~24%). Protein hydrolysates were prepared from pea isolate by enzymatic hydrolysis using pepsin and pancreatin. Hydrolysates were evaluated for their amino acid composition, antioxidant properties, in vitro and in vivo antihypertensive properties. The hydrolysates had high hydrophobic amino acids, especially isoleucine, phenylalanine, and leucine. Pepsin‐pancreatin‐hydrolyzed pea protein (PPHPp) showed significantly higher ability to scavenge DPPH˙ while pancreatin‐hydrolyzed pea protein (PPHPa) had higher ˙OH, ABTS˙+ scavenging, Fe3+ reducing and linoleic acid peroxidation inhibition. PPHPp exhibited superior angiotensin‐converting enzyme inhibition (61.82%) while PPHPa showed higher renin inhibition (14.28%). PPHPp exhibited strong antihypertensive effect, showing an instantaneous systolic blood pressure lowering effect (−26.12 mmHg) within 2‐h post‐oral administration. Pigeon pea protein hydrolysate (especially from pancreatin digest) could therefore, be a promising source of bioactive peptides and potential ingredient for formulation of functional foods against oxidative stress and hypertension.

Enzymatic release of dipeptidyl peptidase‐4 inhibitors (gliptins) from pigeon pea (Cajanus cajan) nutrient reservoir proteins: In silico and in vitro assessments

“…The total contents of the activity‐associated amino acids in pigeon pea protein was 32%, which was similar to the amounts in the hydrolysates, PepH (35%), PapH (32%), and TheH (33%). Compared to a previously reported amino acid composition (Olagunju et al, , ), the pigeon pea protein in our study had higher amounts of Pro and Val, and lower amounts of Leu and Phe, although the total composition of the activity‐related amino acids are similar. Despite the similarity, particular amino acid composition of the hydrolysates in our study were different (e.g., PapH > PepH > TheH for Pro content), possibly due to the specificity of proteases used in hydrolyzing the pigeon pea proteins.…”

“…A major challenge of the in silico approach is the dearth of in vitro analysis to confirm bioactivity (Agyei et al, ). Using the classic approach, recent studies reported that fermented/hydrolyzed pigeon pea seeds/flour have strong potential for exploration as antioxidative and antihypertensive food ingredients (Nawaz et al, ; Olagunju, Omoba, Enujingha, Alashi, & Aluko, ; Olagunju, Omoba, Enujingha, Alashi, & Aluko, ; Olagunju et al, ). The objectives for this study were to use the bioinformatics approach to assess the potential of nutrient reservoir (storage) proteins in pigeon pea as precursors of DPP‐4‐inhibiting peptides, and to evaluate the relationship between structural features of the proteins and biofunctional parameters of released peptides.…”

Antioxidant Peptides from Sepia esculenta Hydrolyzate Attenuate Oxidative Stress and Fat Accumulation in Caenorhabditis elegans

“…It is common practice to use a model organism in the assessment of the anti-oxidative stress capacity of compounds [ 8 ]. Therefore, an oxidation-damaged model of C. elegans induced by paraquat was constructed to detect the antioxidant activity of the hydrolysate.…”

“…The damaging effects of excessive ROS could be reduced by intracellular antioxidant enzymes including superoxide dismutases (SODs), glutathione peroxidases (GPXs), and catalases (CATs), as well as some non-enzymatic antioxidant molecules such as glutathione (GSH), vitamin C, and E [ 5 , 6 ]. However, subjected to severe stressors such as toxins and oxidants, the endogenous antioxidants may not be sufficient to counteract the destructive effects of ROS, and the intake of dietary antioxidants has been reported to prevent oxidative injury and maintain redox balance [ 7 , 8 , 9 , 10 ].…”

Functional and nutritional characterization of in vitro enzymatic hydrolyzed millets proteins

“…Pearl millet protein isolate (PMPI), finger millet protein isolate (FMPI), and green sorghum millet protein isolate (GSMPI) were enzymatically hydrolyzed in vitro using previously reported method (Olagunju et al., 2018) with slight modifications. Protein isolates (1 g) were dissolved in distilled water (DW) (50 ml) and kept for 10 min into water bath at 80°C to denature the protein.…”