Enantioselectivity in the Ecotoxicity of Amphetamine Using Daphnia magna as the Aquatic Model Organism: Morphophysiological, Behavioral, Reproductive and Biochemical Parameters.

This article focuses on the enantioselective toxicity of amphetamine (AMP), a chiral psychoactive substance, to the freshwater invertebrate Daphnia magna. The study exposed daphnids to racemic AMP (rac-AMP) and its individual enantiomers, (R)-AMP and (S)-AMP, at environmentally relevant concentrations, assessing morphophysiological, behavioral, reproductive, and biochemical endpoints across juvenile and adult life stages. Results showed that AMP affected growth, heart rate, swimming behavior, reproduction, and oxidative stress biomarkers in an enantioselective and context-dependent manner, with (S)-AMP notably reducing body size and fecundity, while rac-AMP stimulated growth and reproduction but decreased heart rate and acetylcholinesterase activity. These findings highlight the importance of considering enantioselectivity in environmental risk assessments of chiral contaminants like AMP, especially given their persistence in wastewater and surface waters and potential impacts on aquatic ecosystems.