Dietary aflatoxin B caused the growth inhibition, and activated oxidative stress and endoplasmic reticulum stress pathway, inducing apoptosis and inflammation in the liver of northern snakehead (Channa argus).

The purpose of this study was to investigate the effects of dietary aflatoxin B (AFB) on growth performance and AFB biotransformation, and hepatic oxidative stress, endoplasmic reticulum (ER) stress, apoptosis, and inflammation in northern snakehead (Channa argus). A total of 600 northern snakeheads (7.52 ± 0.02 g) were divided into five groups (three replicates/group) and fed the diets with AFB at concentrations of 0, 50, 100, 200, and 400 ppb for 8 weeks. The results demonstrated that dietary AFB (≥ 200 ppb) reduced FBW, WG, and SGR. 100, 200, and 400 ppb AFB treatment groups significantly decreased the PER, CRP, C3, C4, IgM, and LYS levels in northern snakehead, while FCR was significant increased. Moreover, dietary AFB (100, 200, and 400 ppb) increased cyp1a, cyp1b (except 400 ppb), and cyp3a mRNA expression levels, while reducing the GST enzymatic activity and mRNA expression levels in northern snakehead. Furthermore, AFB (≥ 100 ppb) increased ROS, MDA, and 8-OHdG levels, and grp78, ire1, perk, jnk, chop, and traf2 mRNA expression levels, and decreased SOD, CAT, GSH-Px, and GSH (except 100 ppb) levels and the gene expression levels of cat, gsh-px (except 100 ppb), and Cu/Zn sod. In addition, AFB (100, 200, and 400 ppb) up-regulated the cyt-c, bax, cas-3, and cas-9 mRNA levels in the liver, while down-regulating the bcl-2 expression levels. Meanwhile, the expression levels of nf-κb, tnf-α (except 100 ppb), il-1β, and il-8 in the liver were up-regulated in AFB treatment groups (≥ 100 ppb), while the iκbα mRNA levels were down-regulated. In summary, dietary AFB reduced growth performance and humoral immunity in northern snakehead. Meanwhile, the cyclic occurrence of oxidative stress and ER stress, and induced apoptosis and inflammation, is one of the main reasons for AFB-induced liver injury in the northern snakehead, which will provide valuable information and a fresh perspective for further research into AFB-induced liver injury in fish.