Butylone effects on swimming behaviour and biochemical parameters on Daphnia magna

• Autor(a) principal: Carvalho, Ana Rita
• Data de Publicação: 2024
• Outros Autores: Gonçalves, Virgínia M. F., Tiritan, Maria Elizabeth, Carrola, João Soares, Castro, Bruno, Ribeiro, Ana Rita Lado Ribeiro, Ribeiro, Cláudia
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://doi.org/10.48797/sl.2024.211
• topic: Poster

Background: Psychoactive substances (e.g. cathinones) may be detected in environmental samples, posing risks to wildlife and human health [1, 2]. Butylone (BTL) is a chiral synthetic cathinone available as a racemate [1]. Nevertheless, both human metabolism and biodegradation at wastewater treatment plants may be enantioselective causing changes in its enantiomeric fraction (EF) [2]. Therefore, enantiomers may exhibit different toxicity effects on non-target aquatic organisms, like daphnia [3]. Objective: This study aimed to assess the sub-chronic effects on Daphnia magna exposed to BTL (racemate and single enantiomers) focusing on swimming behaviour and biochemical parameters. Methods: Daphnids (<24h) were exposed to concentrations of 0.10, 1.0, or 10 µg L-1 of rac-BTL or 0.10, or 1.0 µg L-1 of each BTL enantiomer for 9 days (5 replicates per concentration and a control). On day 5, several swimming parameters were determined and on day 9, daphnids were collected for evaluation of biochemical parameters.  Results: No significant changes were observed in swimming parameters in organisms exposed to rac-BTL. However, organisms exposed to (S)-BTL at 0.10 µg L-1 showed a significant increase in total distance. Regarding oxidative stress, rac-BTL increased tiobarbituric acid reactive species levels at 10 µg L-1, and an increase in reactive oxygen species levels was found after exposure to (S)-BTL at 1.0 µg L-1. A decrease in catalase activity at 0.10 µg L-1 was observed in the organisms exposed to rac-BTL whereas no changes were observed for single enantiomers. The activity of acetylcholinesterase showed a significant decrease at all concentrations of rac-BTL whereas an increase was found after exposure to (R)-BTL at 0.10 µg L-1. Conclusions: This study demonstrates that exposure to BTL may cause enantioselective toxicity effects on D. magna related to swimming parameters, oxidative stress, and enzymatic activity. To understand better the toxicity and mechanisms caused by BTL exposure in D. magna, future studies are ongoing.