Abstract：
Microplastics (MPs) and benzo[a]pyrene (B[a]P) are prevalent environmental pollutants. Numerous studies have extensively reported their individual adverse effects on organisms. However, the combined effects and mechanisms of exposure in mammals remain unknown. Thus, this study aims to investigate the potential effects of oral administration of 0.5μm polystyrene (PS) MPs (1 mg/mL or 5 mg/mL), B[a]P (1 mg/mL or 5 mg/mL) and combined (1 mg/mL or 5 mg/mL) on 64 male SD rats by gavage method over 6-weeks. The results demonstrate that the liver histopathological examination showed that the liver lobules in the combined (5 mg/kg) group had blurred and loose boundaries, liver cord morphological disorders, and significant steatosis. The levels of AST, ALT, TC, and TG in the combined dose groups were significantly higher than those in the other groups, the combined (5 mg/kg) group had the lowest levels of antioxidant enzymes and the highest levels of oxidants. The expression of Nrf2 was lowest and the expression of P38, NF-κB, and TNF-α was highest in the combined (5 mg/kg) group. In conclusion, these findings indicate that the combination of PSMPs and B[a]P can cause the highest levels of oxidative stress and elicit markedly enhanced toxic effects, which cause severe liver damage.
摘要：
微塑料（MPs）和苯并[a]芘（B[a]P）是普遍存在的环境污染物。许多研究已经广泛报道了它们对生物体的个体不利影响。然而,暴露在哺乳动物中的联合作用和机制仍然未知。因此，本研究旨在探讨口服0.5μm聚苯乙烯(PS)MPs(1mg/mL或5mg/mL)的潜在影响,B[a]P（1mg/mL或5mg/mL）和联合（1mg/mL或5mg/mL）在6周内通过管饲法对64只雄性SD大鼠进行。结果表明，肝组织病理学检查显示，联合（5mg/kg）组的肝小叶边界模糊和松散，肝索形态学疾病，和显著的脂肪变性。AST的水平，ALT,TC,联合剂量组的TG明显高于其他组，联合（5mg/kg）组的抗氧化酶水平最低，氧化剂水平最高。Nrf2的表达最低,P38、NF-κB的表达最低,TNF-α在联合（5mg/kg）组中最高。总之,这些发现表明，PSMPs和B[a]P的组合可以引起最高水平的氧化应激并引起显着增强的毒性作用，导致严重的肝损伤.
