The influence of dietary β-glucan on immune, transcriptomic, inflammatory and histopathology disorders caused by deltamethrin toxicity in Nile tilapia (Oreochromis niloticus)

• Published in: Fish & shellfish immunology Vol. 98; pp. 301 - 311
• Main Authors: Dawood, Mahmoud A.O., Abdo, Safaa E., Gewaily, Mahmoud S., Moustafa, Eman M., SaadAllah, Moustafa S., AbdEl-kader, Marwa F., Hamouda, Awatef H., Omar, Amira A., Alwakeel, Rasha A.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2020
• Subjects: Blood profile; Deltamethrin; Histopathology; Immune related genes; Nile tilapia; β-glucan; β-glucan; Blood profile; Immune related genes; Histopathology; Nile tilapia; Deltamethrin
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2020.01.035

The protective role of β-glucan (BG) on liver function, histopathology, immune and antioxidant related gene expressions in Nile tilapia exposed to subacute deltamethrin (DLM) was investigated for 30 days. Fish (28.18 ± 1.34 g) of the 1st and 2nd groups fed the control diet, while the 3rd and 4th groups fed BG at 0.5 g/kg and the 2nd and 4th groups were exposed to DLM (15 μg/L) in rearing water. DLM-treated fish displayed a considerable increase in blood biochemical parameters (creatinine, urea and bilirubin) as well as hepatic enzymes (ALP, AST and ALT) (P < 0.05). Blood total protein, globulin, albumin, WBCs, RBCs, Hb, phagocytic index, phagocytic and lysozyme activities were significantly decreased in fish subjected to DLM (P < 0.05). Fish fed BG showed significantly the lowest cortisol and glucose levels, while fish exposed to DLM without feeding BG showed the highest cortisol and glucose levels (P < 0.05) after 15 and 30 days. Additionally, DLM toxicity caused downregulation in antioxidant (CAT and GPx) and immune (IL-1β and IL-8) related gene expressions, while and IFN-γ, HSP70 and CASP3 were upregulated. The histopathological examination of Nile tilapia exposed to DLM revealed damage in gills, intestine, spleen and liver which confirmed the toxic effects. Conversely, BG presented protective effects and restored the above-mentioned parameters when fish exposed to DLM and fed BG. Thus, BG supplementation exhibited defensive effects against DLM toxicity in Nile tilapia through improving blood biochemical responses, immune, and antioxidant related gene expressions as well as histopathological effects. •Deltamethrin (DLM)-treated fish showed increased blood creatinine, urea, bilirubin, ALP, AST and ALT.•Blood immune responses were decreased in fish exposed to DLM.•DLM downregulated CAT, GPx, IL-1β, IL-8 and IFN-γ genes, while HSP70 and CASP3 were upregulated.•Nile tilapia exposed to DLM revealed abnormal histopathological alterations.•β-glucan presented protective effects and restored the aforementioned parameters.