Isolation, purification and characterization of the antibacterial, antihypertensive and antioxidative properties of the bioactive peptides in the purified and proteolyzed major storage protein of pigeon pea (Cajanus cajan) seeds

Rona Karmela D Bravo; Mark Rickard N Angelia; Lawrence Yves C Uy; Roberta N Garcia; Mary Ann O Torio

doi:10.1016/j.fochms.2021.100062

Isolation, purification and characterization of the antibacterial, antihypertensive and antioxidative properties of the bioactive peptides in the purified and proteolyzed major storage protein of pigeon pea (Cajanus cajan) seeds

Food Chem (Oxf). 2021 Dec 8:4:100062. doi: 10.1016/j.fochms.2021.100062. eCollection 2022 Jul 30.

Authors

Rona Karmela D Bravo¹, Mark Rickard N Angelia¹, Lawrence Yves C Uy^{1

2

3

4}, Roberta N Garcia⁵, Mary Ann O Torio¹

Affiliations

¹ Institute of Chemistry, Physical Sciences Building, University of the Philippines Los Baños, College Laguna 4031, Philippines.
² Southeast Asian Regional Center for Graduate Study and Research in Agriculture, College, Los Baños, 4031, Laguna, Philippines.
³ University of the Philippines Los Baños Graduate School, College, Los Baños, 4031, Laguna, Philippines.
⁴ German Academic Exchange Service (DAAD), Postfach 200404, D-53134 Bonn, Germany.
⁵ Institute of Crop Science, College of Agriculture and Food Science, University of the Philippines Los Baños, College, Laguna 4031, Philippines.

Abstract

Previous studies in pigeon pea showed health benefits but very few explored peptide bioactivities. This study examined antimicrobial, antioxidant, and antihypertensive activities of peptides in purified and proteolyzed major globulin fraction, cajanin, of pigeon pea (Cajanus cajan) seeds. In-silico analysis showed 41 antihypertensive and nine antioxidant peptides but zero antibacterial peptides from cajanin sequence. The Pepsin-Chymotrypsin-Trypsin (PCT) protein digest has no antibacterial activity against Escherichia coli, Candida albicans, and Staphylococcus aureus but has high % ACE inhibition (87.50%). Two HPLC fractions showed low IC₅₀ values (HPLC Fraction 1: 0.00535 mg/ml; HPLC Fraction 2: 0.00432 mg/ml), comparable to Captopril (0.00379 mg/ml). This fractions also showed H₂O₂ scavenging activity (HPLC Fraction 1: 1.47%; HPLC Fraction 2: 1.51%) and Total Antioxidative Capacity of 0.00088 mg/mL (HPLC Fraction1) and 0.00110 mg/mL (HPLC Fraction 2) ascorbic acid equivalent. Results from this study serve as reference for further investigations of novel pharmaceutical agents that can be derived from legumes.

Keywords: Antibacterial; Antihypertensive; Antioxidative; Bioactive peptides; Cajanus cajan; Globulin; Pigeon pea.