Yao Mengyao, Qian Jingran, Chen Xiaoni, Liu Jilong, Yang Xiaoqing, Gao Peng, Zhang Cheng
Institute of Environmental Processes and Pollution Control, School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, China.
Department of Environmental and Occupational Health, and Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, PA 15261, United States.
Waste Manag. 2023 Oct 4;171:443-451. doi: 10.1016/j.wasman.2023.09.038.
Agricultural films are extensively utilized in high-intensity agriculture, with China's annual usage reaching 1.5 million tons. Unfortunately, the recovery rate is less than 60%, leading to an inevitable accumulation of plastic mulch in agricultural soils. This accumulation primarily introduces butyl benzyl phthalate (BBP) into soil ecosystems, whose specific effects remain largely unclear, thereby posing potential risks. The present study focuses on the exposure impact of BBP on earthworms, Metaphire guillelmi, a commonly found endogenic earthworm within real farmland, as it provides insight into the direct interaction between biota gut health and contaminants. Specifically, we studied the biomarkers related to oxidative stress, the digestive system, and neurotoxicity within the gut of Metaphire guillelmi, and the integrated biological response (IBR) index was utilized to track these markers at different timeframes after BBP exposures. Our findings indicate that BBP exposures lead to oxidative damage, digestive system inhibition, and neurotoxicity, with IBR indexes of 14.6 and 17.3 on the 14th and 28th days, respectively. Further, the underlying mechanisms at a molecular level through molecular docking were investigated. The results showed that the most unstable interaction was with the NaK-ATPase (binding energy: -2.25 kcal), while BBP displayed stable bonds with superoxide dismutase and 8-hydroxydeoxyguanosine via hydrogen bonds and hydrophobic interaction. These interactions resulted in changes in protein conformation and their normal physiological functions, offering new insights into the molecular mechanism underlying enzymatic activity changes. This study has significant implications for the prediction of toxicity, environmental risk assessment, and the establishment of regulations related to BBP.
农用薄膜在高强度农业中被广泛使用，中国的年使用量达到150万吨。不幸的是，回收率不到60%，导致农用土壤中不可避免地积累了塑料地膜。这种积累主要将邻苯二甲酸丁苄酯（BBP）引入土壤生态系统，其具体影响在很大程度上仍不清楚，从而带来潜在风险。本研究聚焦于BBP对威廉腔环蚓的暴露影响，威廉腔环蚓是实际农田中常见的内生蚯蚓，因为它能深入了解生物肠道健康与污染物之间的直接相互作用。具体而言，我们研究了与威廉腔环蚓肠道内氧化应激、消化系统和神经毒性相关的生物标志物，并利用综合生物反应（IBR）指数在BBP暴露后的不同时间框架内追踪这些标志物。我们的研究结果表明，BBP暴露会导致氧化损伤、消化系统抑制和神经毒性，在第14天和第28天的IBR指数分别为14.6和17.3。此外，通过分子对接研究了分子水平上的潜在机制。结果表明，最不稳定的相互作用是与钠钾ATP酶（结合能：-2.25千卡），而BBP通过氢键和疏水相互作用与超氧化物歧化酶和8-羟基脱氧鸟苷形成稳定的键。这些相互作用导致蛋白质构象及其正常生理功能发生变化，为酶活性变化的分子机制提供了新的见解。本研究对BBP的毒性预测、环境风险评估以及相关法规的制定具有重要意义。
