Immunological and antioxidant role of curcumin in ameliorating fipronil toxicity in Nile tilapia (Oreochromis niloticus)

This study was carried out to investigate the ameliorating effect of dietary curcumin Curcuma longa (CUR) against the subacute toxicity of fipronil (FIP) on Oreochromis niloticus. One hundred and eighty fish were divided into six groups and kept for 30 days; the first group was kept as a control group fed on commercial diet, while the second and third groups were fed on commercial diets supplemented with 1% (CUR1) and 3% (CUR3) curcumin powder/kg diet respectively. The fourth (FIP), fifth (FIP1) and sixth (FIP3) experimental groups were intoxicated with FIP (1/10 96 h LC50), where (FIP1) and (FIP3) groups were fed on a commercial diet supplemented with 1% and 3% of curcumin powder respectively. Hepatorenal damage markers, immunological, tissue antioxidant parameters and anterior kidney expression of IL‐8, IL‐1β and TGF‐β1 genes were determined. Curcumin alleviated the deteriorative effects of FIP intoxication through decreasing hepatic and renal damage markers, improving serum respiratory burst and lysozyme activities. Curcumin provoked a marked decrease in hepatic and renal malondialdehyde and nitric oxide concentration with a significant improvement in tissues' antioxidant status in FIP‐intoxicated fish. Gene expression analysis revealed a significant down‐expression of pro‐inflammatory markers genes after supplementation of curcumin in FIP‐intoxicated fish. In conclusion, the use of 3% curcumin as a feed additive could be implemented to protect fish against the toxic effects of agrochemical wastes via restoring antioxidant and immunological parameters of intoxicated fish.