Cytotoxic effects of polyethylene microplastics isolated and mixed with the pesticides imidacloprid and tebuconazole on fish: an in vitro approach

• Grant number: 24/16532-6
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: June 01, 2025
• End date: May 31, 2026
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Evaldo Luiz Gaeta Espindola
• Grantee: David Silva Alexandre
• Supervisor: David Hernandez-Moreno
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Spain
• Associated to the scholarship: 24/00791-2 - Ecotoxicological effects of the microplastic polyethylene and the pesticide imidacloprid, alone and in a mixture, on the aquatic invertebrates Daphnia similis (Cladocera) and Hyalella meinerti (Amphipoda), BP.DR

Abstract

Emerging contaminants, such as microplastics (MPs) and pesticides, are increasingly recognized for their potential risks to aquatic ecosystems and human health. MPs are frequently detected in surface waters, with concentrations exceeding 51,000 particles/m³, while pesticides like imidacloprid and tebuconazole are commonly found due to agricultural runoff. Both MPs and pesticides are known to cause physiological, reproductive, genetic, and morphological damage to aquatic organisms. However, the combined effects of these pollutants remain underexplored. This study employs in vitro techniques to investigate the cytotoxic effects of polyethylene MPs, both alone and in combination with imidacloprid and tebuconazole, on fish cell lines. Endpoints to be assessed include the metabolic activity (Alamar Blue assay), plasma membrane integrity (CFDA-AM assay), and lysosomal function (Neutral Red uptake assay). Furthermore, the effect on the oxidative stress balance will be evaluated by means of 2 different endpoints, the ratio of intracellular reduced/oxidized glutathione (GSH/GSSG) and the levels of malondialdehyde (MDA), a marker of lipid peroxidation. The integration of these endpoints will allow for a comprehensive understanding of the mechanisms of toxicity, addressing the synergistic or additive effects of these contaminants. By examining these interactions, this research aims to enhance the assessment of environmental risks and support the development of more effective regulatory measures to safeguard aquatic ecosystems.