Study of the chemical composition and ecotoxicological evaluation of essential oils in <i>Daphnia magna</i> with potential use in aquaculture
Patrícia Tidori Miura, S. C. do N. de Queiroz, Cláudio Martín Jonsson, Edsandra Campos Chagas, Francisco Célio Maia Chaves, Félix Guillermo Reyes Reyes
Abstract
Essential oils have been used in aquaculture due to their wide range of biological activities. However, even though they have a potentially low risk for fish, it is necessary to assess the risks to nontarget organisms to guarantee their safe use in the environment. Here, we assessed the acute toxicity on the model organism Daphnia magna of seven essential oils of interest in aquaculture (Lippia alba, Lippia gracilis, Lippia sidoides, Mentha arvensis, Mentha piperita, Ocimum gratissimum and Piper callosum). Furthermore, we also studied the chemical composition of essential oils using gas chromatography-mass spectrometry (GC-MS) to relate toxicity to the chemical composition. The half maximal effective concentration values during 48 hours of exposure (EC50-48 h) of the essential oils for D. magna showed toxicity ranging from moderately (EC50-48 h 3.59 mg/L for L. gracilis, followed by L. sidoides, L. alba and O. gratissimum) to slightly toxic (EC50-48 h 43.74 mg/L for M. piperita as the least toxic, M. arvensis and P. callosum). Thus, for the purpose of establishing ecologically safe therapeutic protocols, the correct use of these substances in aquaculture should be considered, as the toxicity of the essential oils observed indicates potential interference with the nontarget organism D. magna.