The Protective Effect of Taurine on Oxidized Fish-Oil-Induced Liver Oxidative Stress and Intestinal Barrier-Function Impairment in Juvenile Ictalurus punctatus

Abstract

Dietary lipids provide energy for growth and development and provide fatty acids necessary for normal structure and biological function. However, oxidized lipids cause oxidative stress and intestinal damage. An 8-week feeding trial with fresh fish oil (FFO, control group), oxidized fish oil (OFO), and taurine-supplemented diets (OFOT, OFO + 0.2% of taurine) was conducted to evaluate the protective effect of taurine on oxidized fish-oil-induced liver oxidative stress and intestine impairment in juvenile Ictaluruspunctatus. The results showed that (1) Growth performance was significantly lower in fish fed OFO than in those fed other diets, whereas the opposite occurred in the hepatosomatic index. (2) OFO-feeding significantly increased lipid deposition compared with the FFO group. The addition of taurine ameliorated the OFO-induced increase in lipid vacuolization in the liver, significantly upregulated lpl mRNA expression, and downregulated fas and srebp1 mRNA expression. (3) OFO-feeding significantly reduced oxidative damage of liver. Compared with the OFO group, the OFOT group remarkably upregulated antioxidant enzyme mRNA expression through the Nrf2-Keap1 signaling pathway based on the transcriptional expression. (4) OFO diets induced intestinal physical and immune barrier damage. Compared with the OFO group, OFOT diets remarkably downregulated il-1β, il-6, tnf-α, and il-8 mRNA expression and upregulated tgf-β mRNA expression through the NF-κB signaling pathway. Besides, the addition of taurine to OFO diets significantly upregulated zo-2 and zo-1 mRNA expression, and downregulated claudin-15 and claudin-12 mRNA expression. In conclusion, oxidized-fish-oil diets can cause negative physiological health effects in Ictaluruspunctatus, while adding taurine can increase growth and antioxidant ability, reduce lipid deposition, and improve intestinal health.

The Effect of Oxidized Fish Oil on Blood Parameters and Liver Histology of Nile Tilapia (Oreochromis niloticus)

“…In the current study, the significantly increasing of serum (ALT, AST) activity on fish fed oxidized oils seems that oxidized fish oil caused liver tissue damage. Similar studies have been found in GIFT Oreochromis niloticus (Yu et al, 2020), Ictalurus punctatus (Liang et al, 2018), Ictalurus punctatus (Shi et al, 2021), when fed with oxidized oil. Whereas, our study result is not matched with the findings of Luo et al, (2021) in feeding (Acipenser schrenckii) with oxidized oil, which showed that oxidized oil did not affect on serum ALT, AST activity.…”

Protective Effects of Emodin on Oxidized Fish Oil-Induced Metabolic Disorder and Oxidative Stress through Notch-Nrf2 Crosstalk in the Liver of Teleost Megalobrama amblycephala

“…In this study, oxidized fish oil led to lipid deposition in the liver, as evidenced by lipid droplets enlargement and accumulation. Similar results were also found in channel catfish [ 29 ], yellow catfish [ 30 ], loach [ 31 ], and largemouth bass [ 32 ]. In the study of channel catfish, lipid deposition in the liver induced by oxidized fish oil was originated from activated lipid synthesis [ 29 ].…”

“…Similar results were also found in channel catfish [ 29 ], yellow catfish [ 30 ], loach [ 31 ], and largemouth bass [ 32 ]. In the study of channel catfish, lipid deposition in the liver induced by oxidized fish oil was originated from activated lipid synthesis [ 29 ]. However, lipid synthesis and lipolysis were both inhibited under oxidative stress in our present study, which was supported by decreased lipase, LPL, TG, TC, and FAS activity, as well as decreased lipid metabolic related gene expression of LPL, ATGL, CPT1, CPT2, COX2, FAS, and SREBP1.…”

“…The present study shows that oxidized fish oil markedly increased T-SOD, GPx, and ASAFR activity, as well as ROS and MDA levels, indicating antioxidant system was activated in the liver of M. amblycephala . Similar studies also confirmed that oxidized fish oil dysregulates antioxidant capacity in channel fish [ 29 ] and tilapia [ 45 ].…”

Antioxidants in Animal Feed

“…The authors suggest their study firstly demonstrated the regulatory roles of glutamine in the fish immune and antioxidant system and reported its inhibitory effects on fish apoptosis and autophagy during pathogenic infection. Furthermore, Shi et al found that oxidized-fish-oil diets can cause negative physiological health effects in channel catfish, while adding taurine can increase growth and antioxidant ability, reduce lipid deposition and improve intestinal health [ 13 ]. These findings could advance the understanding of the molecular mechanism of oxidative stress and provide nutritional mitigative strategies via supplemented micronutrients in aquaculture production.…”