School of Public Health and Zoonoses, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, 114004, India.
Department of VPE, College of Veterinary Science and Animal Husbandry, Rewa, Madhya Pradesh, 486001, India.
Environ Sci Pollut Res Int. 2018 Jun;25(16):15436-15448. doi: 10.1007/s11356-018-1702-2. Epub 2018 Mar 22.
The deltamethrin, a synthetic pyrethroid, is used worldwide and has been linked with several type of acute toxicity. However, effect of low level of deltamethrin alone or in combination with the microbial antigen on pulmonary system is not understood. Lipopolysaccharide (LPS) was used as antigen which is a key inflammatory component of gram-negative bacteria, which induces a distinctive pattern of cytokine release that regulates inflammation. The aim was to determine whether chronic exposure to a low level of deltamethrin alone or in combination with LPS impair the lung response in adult male Swiss albino mice. The mice were orally exposed to different doses of deltamethrin (0.1, 0.05, 0.005, 0.001 mg/kg bwt) and then immunized with LPS at the 60th day. None of the treatment groups contained residues of deltamethrin above the limits of quantification. Deltamethrin combined with LPS challenge caused significant lymphocytosis and neutropenia in group 1 (0.1 mg/kg) mice (P < 0.05). The highest dose of deltamethrin exposure (0.1 mg/kg bwt) alone altered the total cell count significantly in blood and total leukocyte count (TLC) and macrophage count in bronchoalveolar lavage fluid. Microscopic pulmonary damage was evaluated by H&E staining and EM which indicated that two higher doses of deltamethrin, i.e., 0.1 and 0.05 mg/kg bwt, distinctly increased inflammatory cell infiltration and caused alveolar septa thickening and leukocyte infiltration into the alveolar septum (septal cell infiltration) in the lungs. Deltamethrin exposure alone and/or with endotoxin revealed different degrees of immunopositive reaction for Toll-like receptor 4 (TLR4) and pro-inflammatory cytokine-like tumor necrosis factor-alpha (TNFα) in different parts of the lungs. The expression of TLR4 and TNFα in the lung tissue was more pronounced in two higher dose groups. Thus, chronic low-level deltamethrin exposure may impair the main pro-inflammatory response in the lungs which is more pronounced in combination with LPS. Further research is required in direction of the mechanism of action of deltamethrin on the immune cell lineage and their differentiation.
溴氰菊酯是一种合成拟除虫菊酯，在全球范围内广泛使用，并与多种类型的急性毒性有关。然而，单独使用低水平溴氰菊酯或与微生物抗原联合使用对肺部系统的影响尚不清楚。脂多糖 (LPS) 被用作抗原，它是革兰氏阴性菌的关键炎症成分，诱导细胞因子释放的独特模式，调节炎症。目的是确定慢性暴露于低水平溴氰菊酯单独或与 LPS 联合是否会损害成年雄性瑞士白化小鼠的肺部反应。小鼠经口暴露于不同剂量的溴氰菊酯 (0.1、0.05、0.005、0.001 mg/kg bwt)，然后在第 60 天用 LPS 免疫。没有一个治疗组的溴氰菊酯残留量超过定量限。溴氰菊酯与 LPS 联合刺激导致第 1 组 (0.1 mg/kg) 小鼠出现明显的淋巴细胞增多和中性粒细胞减少 (P<0.05)。单独暴露于最高剂量的溴氰菊酯 (0.1 mg/kg bwt) 显著改变了血液中的总细胞计数和总白细胞计数 (TLC) 以及支气管肺泡灌洗液中的巨噬细胞计数。通过 H&E 染色和 EM 评估肺的显微镜损伤，表明两种较高剂量的溴氰菊酯，即 0.1 和 0.05 mg/kg bwt，明显增加了炎症细胞浸润，并导致肺泡隔增厚和白细胞浸润到肺泡隔 (隔细胞浸润) 在肺部。单独暴露于溴氰菊酯和/或内毒素显示 TLR4 和促炎细胞因子样肿瘤坏死因子-α (TNFα) 在肺部不同部位的免疫阳性反应程度不同。TLR4 和 TNFα 在两个较高剂量组的肺组织中的表达更为明显。因此，慢性低水平溴氰菊酯暴露可能会损害肺部的主要促炎反应，而与 LPS 联合使用时更为明显。需要进一步研究溴氰菊酯对免疫细胞谱系及其分化的作用机制。
