A human is exposed to a chemical mixture rather than a single chemical, particularly with the wide spread of nanomaterials. Therefore, the present study evaluated the combined exposure of lead acetate (Pb) and zinc oxide-nanoparticles (ZnO-NPs) compared to each metal alone on the thyroid gland of adult rats. A total of 30 adult male albino rats were divided into four groups, group I (control), group II received Pb (10 mg/kg), group III received ZnO-NPs (85 mg/kg) and group IV co-administrated the two metals in the same previous doses. The materials were gavaged for 8 weeks. The toxicity was assessed through several biochemical parameters. Our results revealed significant body weight reduction relative to increased thyroid weights, decreased both of serum-free triiodothyronine (FT3), tetra-iodothyronine (FT4), increased thyroid-stimulating hormone (TSH), increased serum and thyroid levels of Pb and zinc, significant elevation in tumor necrosis factor-α (TNF-α), reduction in interleukin 4 (IL4), upregulation of Bax, and downregulation of Bcl-2 genes. Additionally, there was significant overexpression of nuclear factor erythroid 2-related factor 2(Nrf2), 8-Hydroxydeoxyguanosine(8-OHdG), the elevation of tissues malondialdehyde (MDA), reduction of tissues total antioxidant capacity (TAC), and disruptive thyroid structural alterations in all metals groups with marked changes in the combined metals group. In conclusion, the combined exposure of Pb and ZnO-NPs induced pronounced toxic thyroid injury, pointing to additive effects in rats than the individual metal effects through different significant changes of disruptive thyroid structural alterations related to the loading of thyroid tissues with Pb and zinc metals producing oxidative stress that mediated inflammation and apoptosis.

中文翻译：

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联合氧化铅和氧化锌纳米颗粒通过 8-OHdG 氧化应激介导的炎症、细胞凋亡和 Nrf2 激活诱导大鼠甲状腺毒性

人类接触的是一种化学混合物，而不是一种单一的化学物质，尤其是在纳米材料的广泛传播下。因此，本研究评估了成年大鼠甲状腺上醋酸铅 (Pb) 和氧化锌纳米颗粒 (ZnO-NPs) 与单独每种金属的组合暴露情况。将 30 只成年雄性白化大鼠分为四组，I 组（对照组）、II 组接受 Pb（10 mg/kg）、III 组接受 ZnO-NPs（85 mg/kg）和 IV 组共同给药两种金属的先前剂量相同。材料被强饲8周。通过几个生化参数评估毒性。我们的结果显示，相对于增加的甲状腺重量，体重显着降低，无血清三碘甲状腺原氨酸 (FT3)、四碘甲状腺原氨酸 (FT4)、促甲状腺激素 (TSH) 增加、血清和甲状腺中铅和锌水平升高、肿瘤坏死因子-α (TNF-α) 显着升高、白细胞介素 4 (IL4) 减少、Bax 上调和 Bcl-下调2个基因。此外，核因子红系 2 相关因子 2（Nrf2）、8-羟基脱氧鸟苷（8-OHdG）显着过度表达，组织丙二醛（MDA）升高，组织总抗氧化能力（TAC）降低，破坏性甲状腺所有金属组的结构变化，组合金属组发生显着变化。总之，Pb 和 ZnO-NPs 的联合暴露会导致明显的毒性甲状腺损伤，