The protective role of daidzein in intestinal health of turbot (Scophthalmus maximus L.) fed soybean meal-based diets

Guijuan Yu,Jihong Dai,Qinghui Ai,Kangsen Mai,Yanjiao Zhang,Wenbing Zhang,Yang Liu,Weihao Ou

doi:10.1038/s41598-021-82866-1

Abstract

Soybean meal-induced enteropathy (SBMIE) is prevalent in aquaculture. The aim of this study is to evaluate the role of daidzein on SBMIE of juvenile turbot (Scophthalmus maximus L.) by feeding with fish meal diet (FM), soybean meal diet (SBM, 40% fish meal protein in FM replaced by soybean meal protein) and daidzein diet (DAID, 40 mg/kg daidzein supplemented to SBM) for 12 weeks. We found that daidzein supplementation elevated the gene expression of anti-inflammatory cytokine TGF-β, decreased gene expression of pro-inflammatory cytokines TNF-α and signal molecules p38, JNK and NF-κB. SBM up-regulated the genes expression related to oxidative stress and apoptosis, but dietary daidzein restored it to the similar level with that in FM group. Moreover, dietary daidzein up-regulated gene expression of tight junction protein, and modified the intestinal microbial profiles with boosted relative abundance of phylum Proteobacteria and Deinococcus–Thermus, genera Sphingomonas and Thermus, species Lactococcus lactis, and decreased abundance of some potential pathogenic bacteria. In conclusion, dietary daidzein could ameliorate SBM-induced intestinal inflammatory response, oxidative stress, mucosal barrier injury and microbiota community disorder of turbot. Moreover, p38, JNK and NF-κB signaling might be involved in the anti-inflammatory process of daidzein, and daidzein itself might act as an antioxidant to resist SBM-induced oxidative damage.

Highlights

Intestine, the important interface between the host and the external environment, is continually exposed to the external stimulations such as diets and environmental factors, which makes it vulnerable to d amage[1]
Diet SBM significantly up-regulated the mRNA expression of pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and signaling molecules p38, extracellular regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and nuclear transcription factor-κB (NF-κB), and down-regulated the expression of anti-inflammatory cytokine transforming growth factor-β (TGF-β) (P < 0.05) (Fig. 1)
The daidzein supplementation significantly suppressed the expression of TNF-α, p38, JNK and NF-κB, and increased TGF-β expression compared with SBM group (P < 0.05)

Summary

Introduction

The important interface between the host and the external environment, is continually exposed to the external stimulations such as diets and environmental factors, which makes it vulnerable to d amage[1]. Numerous studies on mammals and human cancer cell show that daidzein could attenuate inflammation and oxidative stress, induce the apoptosis of cancer cell, and modulate the intestinal bacterial composition[18,20,21]. Tomar et al.[21] found that mitogen-activated protein kinase (MAPK) signaling was crucial in daidzein-mitigated inflammation, oxidative stress and apoptosis in cisplatin-induced kidney injury of rats. The roles of daidzein in mitigating adverse effects of high soybean meal level on the intestinal health, as well as the mechanisms involved, remain unknown. The purpose of the present study was to explore the effects of daidzein on SBMIE of turbot in terms of the intestinal inflammation, oxidative stress, intestinal integrity and microbiota, as well as the mechanisms involved, which would provide a better understanding of daidzein physiology in fish

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Conclusion