Immune-protective, antioxidant and relative genes expression impacts of β-glucan against fipronil toxicity in Nile tilapia, Oreochromis niloticus

Abstract Our study considered to attempt reducing the immune-toxic and antioxidant impacts of exposure to fipronil (FP) on Nile tilapia, Oreochromis niloticus using the β-glucan (βG). Two hundred and seventy fingerlings of Nile tilapia were divided randomly into six groups (45 fish each, with 3 replicates each): group I control (CT) group nourished on a basal diet. Group II (βG) nourished a basal diet supplemented with 0.4% βG. Group III (1/20 FP) and group V (1/10 FP) was exposed to 1/20 and 1/10 of the 96 h LC50 of FP in water and nourished the basal diet respectively. Group IV (1/20 FP+ βG) and group VI (1/10 FP+ βG) for 90 successive days. Growth performance metrics were higher in βG group than CT. While those metrics were fallen at exposure to 1/20 or 1/10 FP. Supplementation with βG elevated the IgM and lysozyme levels.Whereas, tilapias exposed to FP only at different concentration showed lowering of those compared to CT. βG was effectively augmented IgM and lysozyme in 1/20 FP exposed tilapias. Furthermore, in a minor grade at 1/10 FP exposed tilapias. Exposure to FP increased the activities of hepatic markers chiefly at 1/10, however the βG supplementation was successfully improved these markers. There was imbalance of cortisol level at FP exposure where βG combining to FP alleviate this disparity. There was fallen in LDH, MDH and FDPase in βG tilapias where continuing raise in 1/10 FP followed by 1/20 FP. βG supplementation raise the level of GSH, without significant variations in MDA conversely occurs in FP alone. Gene expression of βG caused raise of both GPx and GR, without fluctuations in CAT and SOD. Exposure to FP diminishes all evaluated antioxidant genes. It could fulfilled that supplementation with βG successfully alleviated the immune-toxic and antioxidant impact of FP in tilapias.