Nanoplastics (NPs) are omnipresent in our lives as a new type of pollution with a tiny size. It can enter organisms from the environment, accumulate in the body, and be passed down the food chain. Inflammatory bowel disease (IBD) is a nonspecific intestinal inflammatory disease that is recurrent and prevalent in the population. Given that the intestinal features of colitis may affect the behavior and toxicity of NPs, it is imperative to clarify the risk and toxicity mechanisms of NPs in colitis models. In this study, mice were subjected to three cycles of 5-day dextran sulfate sodium (DSS) exposures, with a break of 7 to 11 days between each cycle. After the first cycle of DSS exposure, the mice were fed gavagely with water containing 100 nm polystyrene nanobeads (PS-NPs, at concentrations of 1 mg/kg·BW, 5 mg/kg·BW and 25 mg/kg·BW, respectively) for 28 consecutive days. The results demonstrated that cyclic administration of DSS induced chronic inflammation in mice, while the standard drug “5-aminosalicylic acid (5-ASA)” treatment partially improved colitis manifestations. PS-NPs exacerbated intestinal inflammation in mice with chronic colitis by activating the MAPK signaling pathway. Furthermore, PS-NPs aggravated inflammation, oxidative stress, as well as hepatic lipid metabolism disturbance in the liver of mice with chronic colitis. PS-NPs exacerbate intestinal inflammation and injury in mice with chronic colitis. This finding highlights chronically ill populations’ susceptibility to environmental hazards, which urgent more research and risk assessment studies.

中文翻译：

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聚苯乙烯纳米珠加剧小鼠慢性结肠炎，涉及氧化应激和肝脂质代谢

纳米塑料（NP）作为一种体积微小的新型污染物，在我们的生活中无处不在。它可以从环境进入生物体，在体内积累，并沿着食物链传递。炎症性肠病（IBD）是一种非特异性肠道炎症性疾病，在人群中反复流行。鉴于结肠炎的肠道特征可能影响纳米颗粒的行为和毒性，因此有必要阐明纳米颗粒在结肠炎模型中的风险和毒性机制。在这项研究中，小鼠接受了三个周期的为期 5 天的葡聚糖硫酸钠 (DSS) 暴露，每个周期之间休息 7 至 11 天。第一个周期的 DSS 暴露后，给小鼠灌胃喂含有 100 nm 聚苯乙烯纳米珠（PS-NPs）的水，浓度分别为 1 mg/kg·BW、5 mg/kg·BW 和 25 mg/kg·BW ）连续28天。结果表明，周期性给予DSS会引起小鼠慢性炎症，而标准药物“5-氨基水杨酸（5-ASA）”治疗部分改善结肠炎表现。 PS-NPs 通过激活 MAPK 信号通路加剧了慢性结肠炎小鼠的肠道炎症。此外，PS-NPs还会加重慢性结肠炎小鼠肝脏的炎症、氧化应激以及肝脂代谢紊乱。 PS-NP 会加剧慢性结肠炎小鼠的肠道炎症和损伤。这一发现凸显了慢性病人群对环境危害的易感性，这迫切需要更多的研究和风险评估研究。