Effects of lomefloxacin on survival, growth and reproduction of Daphnia magna under simulated sunlight radiation

• Published in: Ecotoxicology and environmental safety 2018-12, Vol.166, p.63-70
• Main Authors: Luo, Tianlie, Chen, Jingwen, Li, Xuehua, Zhang, Shuying, Yao, Hongye, Peijnenburg, Willie J.G.M.
• Format: Article
• Language: English
• Subjects: Animals; Catalase - metabolism; Chronic toxicity; Daphnia - drug effects; Daphnia - radiation effects; Daphnia magna; Fluoroquinolones - toxicity; Lipid Peroxidation - drug effects; Lomefloxacin; Oxidative Stress - drug effects; Photo-induced toxicity; Reactive oxygen species; Reactive Oxygen Species - metabolism; Reproduction - drug effects; Sunlight; Superoxide Dismutase - metabolism; Ultraviolet Rays; Water Pollutants, Chemical - toxicity
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2018.09.067

Lomefloxacin, an antibacterial agent with known photo-induced toxicity in clinical studies, is frequently detected in aquatic environments. Investigating the photo-induced toxicity of lomefloxacin in aquatic organisms is therefore of importance for assessing its ecological risks. In this study, the effects of lomefloxacin on survival, growth and reproduction of Daphnia magna under simulated sunlight radiation (SSR) were investigated, and the mechanism of action was revealed. Results indicated that SSR containing UV radiation increased the acute toxicity of lomefloxacin to Daphnia magna relative to white fluorescent light irradiation. Under SSR, 100 μM lomefloxacin significantly enhanced reactive oxygen species (ROS) generation and lipid peroxidation, and decreased activities of superoxide dismutase and catalase. The biochemical observations and apparent effects on the organism indicate that oxidative stress plays a central role in the acute photo-induced toxicity. Chronic toxicity results showed that SSR significantly affected growth and reproduction of Daphnia magna, whereas lomefloxacin reduced the damage of UV radiation in SSR through light shielding. This study provides insight into the mechanism of photo-induced toxicity and can support the risk assessment of chemicals in the aquatic environment by including the impacts of sunlight irradiation on toxicity. [Display omitted] •Simulated sunlight radiation enhances toxicity of lomefloxacin to Daphnia magna.•Oxidative stress plays a central role in phototoxicity of lomefloxacin to daphnia.•UV and lomefloxacin display an antagonistic joint action on chronic toxicity.