Microplastic-Contaminated Karamana River Water Induced Oxidative Stress-Mediated Genotoxicity in Drosophila melanogaster.

Abstract

Microplastics (MPs) have emerged as persistent pollutants of global environmental concern, posing cumulative risks to biological health. Their accumulation in nature warrants a study to assess potential toxic effects on organisms. This study investigated the toxicological effects of MP-contaminated water from the Karamana River on Drosophila melanogaster under controlled laboratory conditions. Flies were reared on culture media prepared from water samples collected from the river and were evaluated for life-history traits, oxidative stress, antioxidant response, cytotoxicity, and DNA damage. Delayed development, reduced fecundity, decreased midgut cell viability, accompanied by elevated lipid peroxidation and nitric oxide levels, demonstrate the induction of oxidative and nitrosative stress. In parallel, antioxidant defences, including superoxide dismutase, glutathione, and glutathione-S-transferase, were markedly depleted. Increased DNA damage in larval hemocytes signifies MP-induced oxidative stress-mediated genotoxicity. Collectively, these endpoints indicate that complex mixtures of MPs along with co-occurring pollutants in river water initiate a cascade of oxidative, cytotoxic, and genotoxic responses in Drosophila. Using D. melanogaster as a model organism, this study examines the health risks associated with real-world MP contamination and underscores the broader ecological implications of urban river pollution.