EVALUATION OF THE SUBTLE EFFECTS AND OXIDATIVE STRESS RESPONSE OF CHLORAMPHENICOL, THIAMPHENICOL AND FLORFENICOL ON DAPHNIA MAGNA.

Phenicol antibiotics, such as chloramphenicol (CAP), thiamphenicol (TAP) and florfenicol (FLO), are commonly used in the veterinary and aquaculture fields to treat diseases and have been frequently detected in aquatic environments. Nevertheless, there is limited information regarding the effects of phenicol antibiotics on aquatic non-target species. Thus, the present study aims to investigate the long-term (21-d) influence on the reproduction and growth of and the acute (24-h) oxidative response and tissue damage in the crustacean Daphnia magna after exposure to phenicol drugs, including their environmental concentrations. The results indicated that D. magna exposed to FLO are likely to cause more adverse effects than those exposed to CAP and TAP for long-term (21-d) exposures. Furthermore, changes in the biochemical biomarkers such as malondialdehyde (MDA), catalase (CAT) and reduced glutathione (GSH) induced by individual and mixtures of phenicol antibiotics were also observed. Low concentrations of CAP, TAP + FLO and CAP + TAP significantly increased the MDA levels of D. magna after 24-h exposures, causing cellular oxidative damage in the animals. In addition, discrepancies between the CAT activities and GSH levels were observed in the current study, underscoring the need to evaluate multiple indicators of oxidative stress in toxicological studies using D. magna as a model. This article is protected by copyright. All rights reserved.