Article

Improved immune-enhancing activity of egg white protein ovotransferrin after enzyme hydrolysis

Jae Hoon Lee1, Hyeon Joong Kim1, Dong Uk Ahn2, Hyun-Dong Paik1,*
Author Information & Copyright
1Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Korea.
2Department of Animal Science, Iowa State University, Ames 50011, United States.
*Corresponding Author: Hyun-Dong Paik, Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Korea, Republic of. E-mail: hdpaik@konkuk.ac.kr.

© Copyright 2021 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: Mar 31, 2021; Revised: May 07, 2021; Accepted: Jun 02, 2021

Published Online: Jul 26, 2021

Abstract

Ovotransferrin (OTF), an egg protein known as transferrin family protein, possess strong antimicrobial and antioxidant activity. This is because OTF has two iron binding sites, so it has a strong metal chelating ability. The present study aimed to evaluate the improved immune-enhancing activities of OTF hydrolysates produced using bromelain, pancreatin, and papain. The effects of OTF hydrolysates on the production and secretion of pro-inflammatory mediators in RAW 264.7 macrophages were confirmed. The production of nitric oxide (NO) was evaluated using Griess reagent and the expression of inducible nitric oxide synthase (iNOS) were evaluated using quantitative real-time PCR. And the production of pro-inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-6) and the phagocytic activity of macrophages were evaluated using an ELISA assay and neutral red uptake assay, respectively. All OTF hydrolysates enhanced NO production by increasing iNOS mRNA expression. Treating RAW 264.7 macrophages with OTF hydrolysates increased the production of pro-inflammatory cytokines and the phagocytic activity. The production of NO and pro-inflammatory cytokines induced by OTF hydrolysates was inhibited by the addition of specific MAPK inhibitors. In conclusion, results indicated that all OTF hydrolysates activated RAW 264.7 macrophages by activating MAPK signaling pathway.

Keywords: ovotransferrin; hydrolysates; immune-enhancing activity; MAPK pathway