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.

中文翻译：

---

饮食中β-葡聚糖对尼罗罗非鱼中溴氰菊酯毒性引起的免疫，转录组，炎性和组织病理学疾病的影响。

研究了β-葡聚糖（BG）对亚急性溴氰菊酯（DLM）暴露的尼罗罗非鱼肝功能，组织病理学，免疫和抗氧化相关基因表达的保护作用，持续30天。第一和第二组的鱼（28.18±1.34 g）饲喂对照饮食，而第三和第四组的BG饲喂0.5 g / kg，第二和第四组在饲养水中暴露于DLM（15μg/ L） 。经DLM处理的鱼的血液生化参数（肌酐，尿素和胆红素）以及肝酶（ALP，AST和ALT）显着提高（P <0.05）。接受DLM处理的鱼的血液总蛋白，球蛋白，白蛋白，白细胞，红细胞，血红蛋白，吞噬指数，吞噬和溶菌酶活性显着降低（P <0.05）。饲喂BG的鱼的皮质醇和葡萄糖水平最低，而未饲喂BG的DLM鱼在15天和30天后显示出最高的皮质醇和葡萄糖水平（P <0.05）。此外，DLM毒性导致抗氧化剂（CAT和GPx）和免疫（IL-1β和IL-8）相关基因表达下调，而IFN-γ，HSP70和CASP3上调。暴露于DLM的尼罗罗非鱼的组织病理学检查显示g，肠，脾和肝受到损害，证实了其毒性作用。相反，当鱼暴露于DLM并喂食BG时，BG表现出保护作用并恢复了上述参数。因此，BG补充剂通过改善血液生化反应，免疫和抗氧化剂相关基因表达以及组织病理学作用，对尼罗罗非鱼的DLM毒性表现出防御作用。