Effect of dietary enzyme‐treated soy protein on the immunity and antioxidant status in the intestine of juvenile Jian carp ( Cyprinus carpio var. Jian)

Abstract

This study was conducted to evaluate the hypothesis that enzyme‐treated soy protein (ETSP) can save the fish dietary protein, and further investigated the mechanism for saving effect by studying the effects of ETSP on intestinal immune response and antioxidant status in juvenile Jian carp (Cyprinus carpio var. Jian). Compared with the high‐protein diet, results showed that decreasing 2% of dietary protein increased the protein carbonyl (PC) content, decreased the anti‐hydroxyl radical capacity (AHR) and superoxide dismutase (SOD) activity and increased the relative expressions of pro‐inflammatory cytokine (p < 0.05). The low‐protein diet might impair the intestinal health, so as to reduce fish growth performance. After adding 1.5% or 2% of ETSP to the low‐protein diet, results indicated that (1) ETSP decreased the relative expressions of pro‐inflammatory cytokine and increased the relative expressions of anti‐inflammatory cytokine (p < 0.05). (2) ETSP decreased malondialdehyde (MDA) and PC content (p < 0.05), improved activities of antioxidant enzymes, glutathione (GSH) content, relative expressions of antioxidant enzymes and Nrf2, which were even much higher than the high‐protein diet (p < 0.05). All the above data suggested that optimal level of ETSP can save 2% of fish dietary protein which might be partly attributed to improve intestinal health through regulating intestinal immunity response and antioxidant status.

The application of protease in aquaculture: Prospects for enhancing the aquafeed industry

“…(2020) demonstrated that dietary enzymatically hydrolyzed soy protein can alleviate inflammatory responses by regulating the NF-κB and TOR signaling pathways. In Jian carp C. carpio var, Xiao et al. (2019) reported that protease-treated soy protein could decrease MDA and protein carbonyl contents, improve the activities of antioxidant enzymes and glutathione contents, and enhance mRNA expressions of antioxidant enzymes and Nrf2 .…”

Effects of Dietary Vegetable Oil Mixtures including Soybean Oil on Intestinal Oxidative Stress in Gilthead Sea Bream (Sparus aurata)

“…It is known that an increase in ROS triggers DNA damage, enzyme inactivation, protein oxidation, and lipid peroxidation (LPO) [ 20 ]. This could compromise the physical barrier function at intestinal level by causing negative effects on membrane structure, fluidity and permeability [ 21 ] and thus, negatively affect fish welfare [ 22 , 23 , 24 ].…”

“…Specific studies on oxidative status in pyloric caeca and proximal intestine are scarce despite that are multiple external and internal triggers inducting oxidative stress at intestinal level [ 21 , 22 , 27 , 28 , 29 , 30 , 31 , 32 ]. To our knowledge, two studies in this area have been conducted in gilthead sea bream, an important species for Mediterranean aquaculture [ 22 , 30 ].…”

Effects of different dietary levels of soybean protein hydrolysates on the growth performance, antioxidant capacity and relative mRNA expression levels of juvenile hybrid grouper ( Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂)

“…After the appropriate process of hydrolysates, the quality and biological properties of plant proteins have been greatly improved (McCarthy, O’Callaghan, & O’Brien, 2013). The researches of plant protein hydrolysates for fish mainly focus on soybean protein hydrolysates (Xiao et al., 2019), cottonseed meal protein hydrolysate (Yuan et al., 2019) and others, which are more effective to support better growth performance and elevate antioxidant ability.…”