Nisha A R, Hazilawati H, Mohd Azmi M L, Noordin M M
a Department of Pathology and Microbiology, Faculty of Veterinary Medicine , Universiti Putra Malaysia , Serdang , Selangor , Malaysia.
b Department of Veterinary Pharmacology and Toxicology , College of Veterinary and Animal sciences , Wayanad , Kerala , India.
Toxicol Mech Methods. 2017 Mar;27(3):215-222. doi: 10.1080/15376516.2016.1273432. Epub 2017 Jan 18.
Polycyclic aromatic hydrocarbons (PAHs) are persistent pollutants and chemically a class of structurally similar chemical compounds characterized by the presence of fused aromatic rings. This research was undertaken to find out immunotoxic effects produced by pyrene, phenanthrene and fluoranthene. These chemicals were injected into developing chicks at three dose levels (0.2, 2 and 20 mg per kg) through allantioc route to rule out possible mechanisms involved in immunotoxicity. DNA adduct produced by PAHs in immune organs were analyzed by DNA adduct enzyme-linked immunosorbent assay (ELISA) kit and DNA damage was assessed by comet assay. A significant increase in the DNA adduct levels was found in thymus and bursa in 2 mg and 20 mg dose levels of pyrene, fluoranthene and phenanthrene treated groups, whereas those in spleen simulated the value of controls. Comet assay indicated that PAHs especially pyrene, fluoranthene and phenanthrene were capable of inducing increased level of comet parameters in thymus at all the dose levels. Bursa of Fabricius and spleen also showed a gradual rise in comet parameters corresponding to all dose levels, but the increase was more marked as in thymus. Thus, it can be concluded that DNA adducts produced by PAHs lead to single-strand breaks and reduced DNA repair, which ultimately begin a carcinogenic process. Hence, this experiment can be considered as a strong evidence of genotoxic potential of PAHs like pyrene, phenanthrene and fluoranthene in developing chicks.
多环芳烃（PAHs）是持久性污染物，在化学上是一类结构相似的化合物，其特征是存在稠合芳香环。本研究旨在探究芘、菲和荧蒽产生的免疫毒性作用。通过腹腔注射途径，以三种剂量水平（每千克0.2、2和20毫克）将这些化学物质注射到发育中的雏鸡体内，以排除免疫毒性可能涉及的机制。通过DNA加合物酶联免疫吸附测定（ELISA）试剂盒分析PAHs在免疫器官中产生的DNA加合物，并通过彗星试验评估DNA损伤。在芘、荧蒽和菲处理组的2毫克和20毫克剂量水平下，胸腺和法氏囊中DNA加合物水平显著增加，而脾脏中的DNA加合物水平与对照组相当。彗星试验表明，PAHs尤其是芘、荧蒽和菲在所有剂量水平下均能诱导胸腺中彗星参数水平升高。法氏囊和脾脏中的彗星参数也随着所有剂量水平逐渐升高，但升高程度不如胸腺明显。因此，可以得出结论，PAHs产生的DNA加合物导致单链断裂并减少DNA修复，最终引发致癌过程。因此，本实验可被视为芘、菲和荧蒽等PAHs对发育中的雏鸡具有遗传毒性潜力的有力证据。
