Sulforaphane alleviates oxidative stress induced by oxidized fish oil in Litopenaeus vannamei by involving antioxidant capacity, inflammation, autophagy, and apoptosis

Abstract

Sulforaphane (SFN) is an antioxidant. Unsaturated fatty acids are rich in fish oil, and they are indispensable fatty acids for aquatic animals to grow and reproduce. However, fish oil is easily oxidized, which could have adverse effects on aquatic animals. In this study, Litopenaeus vannamei was divided into four groups: fresh fish oil group (control group), oxidized fish oil group (OFO group), OFO plus low-concentration SFN group (OFO + SL group), and OFO plus high-concentration SFN group (OFO + SH group). A 28-day experiment was conducted, and the antioxidant capacity, inflammation, autophagy, and pathological characteristics were investigated to explore whether SFN could protect L. vannamei from oxidative stress induced by OFO. Results showed that OFO significantly increased the contents of MDA in hepatopancreas, muscle and serum, while high concentrations of SFN significantly decreased the MDA compared with the OFO group (P < 0.05). OFO significantly affected the expression of SOD, CAT, GST and HSP 70 and increased the expression of inflammatory-related genes (TNF and spz). SFN downregulated the expression of TNF and spz, upregulate Nrf2, heat shock protein 70 (HSP 70) and autophagy genes (ATG4, ATG5, ATG10, and ATG12) and stabilized the expression of apoptosis-related genes (caspase 2, caspase 3, and JNK, P < 0.05). In addition, histological analysis of hepatopancreas showed that OFO led to cavitation in the lumen, and the existence of SFN reversed this phenomenon. OFO also result in the apoptosis of the hepatopancreas of L. vannamei, and the existence of high-concentration SFN reduced its apoptosis. In summary, SFN is involved in the regulation of antioxidant capacity, inflammation, autophagy, and apoptosis to alleviate the oxidative stress induced by OFO in L. vannamei.