Effects of dietary curcumin inhibit deltamethrin-induced oxidative stress, inflammation and cell apoptosis in Channa argus via Nrf2 and NF-κB signaling pathways

The current study evaluated the ameliorative effects of dietary curcumin (CUR) on oxidative stress, inflammation and cell apoptosis in Channa argus exposed to deltamethrin (DEL) for 28 d. This study was divided into five groups: the first group served as a control group, and the second, third, fourth and fifth groups were exposed to DEL (0.242 ppb) in water and fed CUR-supplemented diets at 0, 100, 200 and 400 mg/kg, respectively. The results showed that the biochemical parameter levels (ADA, COR, LDH, AST and ALT) and the innate immune parameter levels (LYS, CRP, MPO, C3, C4 and IgM) in the serum of fish exposed to DEL were notably increased (P < 0.05), and dietary supplementation with 200 and 400 mg/kg CUR in the DEL exposure period significantly reduced the levels of these parameters (P < 0.05). The levels of ROS, CAT, GSH, SOD, GSH-Px, GST and GSH-Rt in the gill, kidney, spleen, and liver of fish exposed to DEL were significantly decreased (P < 0.05), and there were notable increases (P < 0.05) in the 200 and 400 mg/kg CUR treatments. MDA content exhibited an opposite trend. The results of RT-qPCR analysis showed that dietary supplementation with CUR attenuated the inflammatory response of fish after DEL exposure by downregulating the expression of pro-inflammatory genes (NF-κB p65, IL-1β, IL-6, IL-8, IL-12 and TNF-α) in the liver and spleen and upregulating the expression of anti-inflammatory genes (TGF-β, IκBα and IL-10). Dietary supplementation with CUR was observed to improve the level of oxidative stress of fish after DEL exposure by downregulating the mRNA levels of Keap1 in the liver and spleen and upregulating the mRNA levels of Nrf2, Cu/Zn SOD, GSH-Px, GST and CAT. Dietary supplementation with CUR was determined to improve the cell apoptosis of fish after DEL exposure by downregulating the expression of pro-apoptotic genes (Bcl-2) in the liver and spleen and upregulating the expression of anti-apoptotic genes (Bax, Cas-3, Cas-8, Cas-9, and p53). In brief, the results of our study indicated that supplying optimal dietary CUR could attenuate deltamethrin-induced oxidative stress, inflammation and cell apoptosis in C. argus via the Nrf2 and NF-κB signaling pathways.