Das Bini C, V P Vineetha, Pillai Devika, V J Rejish Kumar
Department of Aquatic Animal Health Management, Kerala University of Fisheries and Ocean Studies, Kochi, Kerala, India.
Department of Aquaculture, Kerala University of Fisheries and Ocean Studies, Kochi, Kerala, India.
Ecotoxicology. 2025 Jun 19. doi: 10.1007/s10646-025-02914-8.
Numerous ecosystem-based studies have explored microplastic pollution in brackish water environments. However, research on the bioaccumulation of microplastics in brackish water fish and their effects remains limited. The present study investigated the bioaccumulation and effects of polystyrene microplastics (PS-MPs) in juvenile brackish water fish, pearl spot (Etroplus suratensis). Fish were exposed to 0, 0.2, 2, and 4 mg/L of 1 µm-sized PS-MPs for 14 days. PS-MPs were found in the gastrointestinal tract, gills, liver, spleen, muscle, and brain, with the highest concentration in the intestine and the lowest in the brain. Exposure to PS-MPs led to elevated serum level of glucose, total protein, total cholesterol, serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic-pyruvic transaminase (SGPT), and alkaline phosphatase (ALP). Antioxidant parameters such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and total antioxidant capacity (TAC) decreased, while malondialdehyde (MDA) level and protein carbonyl (PC) content increased. PS-MP exposure down-regulated hepatic expression of NRF2 and P53, increased cortisol levels, and up-regulated HSP70 gene expression in a dose-dependent manner. Additionally, PS-MPs down-regulated expression of IGF1 and CYP1A in the liver. This is the first comprehensive research that has revealed the extent to which PS-MPs accumulate in various tissues of brackish water fish species after being exposed to environmentally significant concentrations. It also demonstrates the associated toxicity in an array of antioxidant indicators.
众多基于生态系统的研究已对咸淡水环境中的微塑料污染进行了探索。然而，关于微塑料在咸淡水鱼类中的生物累积及其影响的研究仍然有限。本研究调查了聚苯乙烯微塑料（PS - MPs）在咸淡水幼鱼珍珠斑（Etroplus suratensis）中的生物累积及影响。将鱼暴露于0、0.2、2和4mg/L的1μm大小的PS - MPs中14天。在胃肠道、鳃、肝脏、脾脏、肌肉和大脑中均发现了PS - MPs，其中肠道中的浓度最高，大脑中的浓度最低。暴露于PS - MPs导致血清葡萄糖、总蛋白、总胆固醇、血清谷草转氨酶（SGOT）、血清谷丙转氨酶（SGPT）和碱性磷酸酶（ALP）水平升高。超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPx）和总抗氧化能力（TAC）等抗氧化参数下降，而丙二醛（MDA）水平和蛋白质羰基（PC）含量增加。PS - MP暴露以剂量依赖的方式下调肝脏中NRF2和P53的表达，增加皮质醇水平，并上调HSP70基因表达。此外，PS - MPs下调肝脏中IGF1和CYP1A的表达。这是第一项全面研究，揭示了PS - MPs在暴露于具有环境意义的浓度后在咸淡水鱼类各种组织中的累积程度。它还展示了一系列抗氧化指标中的相关毒性。
