Deltamethrin (DLM) is a synthetic pyrethroid used for agricultural purposes to control insects and has been found to pollute the aquatic environment and leads to serious health problems. Lactobacillus plantaruml-137 (L-137) has gained more popularity as functional supplement for its immunomodulatory effects and antioxidant potential. This study was designed to examine the potential of l-137 on liver function, histopathology, immune and antioxidant related gene expressions in Nile tilapia exposed to subacute DLM for 30 days. Fish (mean weight of 28.18 ± 1.34 g) was distributed into four groups (triplicates): the first and second groups fed the control diet, while the third and fourth groups fed l-137 at 50 mg/kg and the second and fourth groups were exposed to DLM (15 μg/L) in rearing water (control, DLM, l-137 and DLM + L-137, respectively). DLM-treated fish groups showed a significant 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 exposed to DLM (P < 0.05). Additionally, DLM toxicity downregulated the transcription of immune genes (IL-1β and IL-8), while upregulated the stress related genes (HSP70 and CASP3). The histopathological images of Nile tilapia exposed to DLM revealed damage in gills, intestine, spleen and liver which confirmed the toxic effects. Conversely, l-137 presented protective effects and restored the aforementioned parameters when fish exposed to DLM and fed l-137. Further, l-137 restored the antioxidative capacity (CAT and GPx). Thus, l-137 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：

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植物乳杆菌L-137对尼罗罗非鱼（Oreochromis niloticus）在溴氰菊酯在饲养水中的毒性作用的改善作用。

溴氰菊酯（DLM）是一种合成的拟除虫菊酯，用于农业目的以控制昆虫，并且已发现其污染水生环境并导致严重的健康问题。植物乳杆菌137（L-137）因其免疫调节作用和抗氧化潜能而作为功能性补充剂越来越受欢迎。这项研究旨在检查l-137对亚急性DLM暴露30天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潜力。将鱼（平均体重28.18±1.34 g）分为四组（一式三份）：第一和第二组饲喂对照饮食，而第三和第四组饲喂l-137，剂量为50 mg / kg，第二和第四组在饲养水中分别暴露于DLM（15μg/ L）（对照，DLM，l-137和DLM + L-137）。经DLM处理的鱼群显示血液生化参数（肌酐，尿素和胆红素）以及肝酶（ALP，AST和ALT）显着增加（P <0.05）。暴露于DLM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）。此外，DLM毒性下调免疫基因（IL-1β和IL-8）的转录，同时上调与压力相关的基因（HSP70和CASP3）。暴露于DLM的尼罗罗非鱼的组织病理学图像显示in，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1-137时，l-137表现出保护作用并恢复了上述参数。此外，l-137恢复了抗氧化能力（CAT和GPx）。