Evaluation of anti-inflammatory drug diclofenac: effects of growth, energy reserves, and osmolarity of the crayfish Cherax quadricarinatus.

CANOSA, IVANA S.; RAMIREZ, ROCÍO D.; TROPEA, CAROLINA; STUMPF, LÍA; ZANITTI, MARINA; LÓPEZ GRECO, LAURA SUSANA; RODRIGUEZ, ENRIQUE M

Montevideo

Congreso; SETAC Latin America 15th Biennial Meeting; 2023

SETAC

The presence of emerging contaminants in ecosystems has an increasing global concern. Diclofenac (DCF), a non-steroidal anti-inflammatory drug, is one of the most widespread pharmaceutical compounds found in freshwaters. Because of the inadequate wastewater management, this compound is incompletely removed, so it can reach the water bodies impacting the aquatic life. The aim of this study was to evaluate the effects of DCF, at sublethal concentrations, on growth, energy reserves and osmolarity in juveniles of the crayfish Cherax quadricarinatus as a model species of higher crustaceans. For this purpose, a 90 days in vivo assay was carried out. Male and female juveniles weighing from 0.8 to 1.2 g were isolated in glass containers and randomly assigned to one of the following treatments: Control (freshwater), DCF 0,1 mg/L and DCF 1 mg/L. The assay was conducted under controlled conditions of feeding, photoperiod, aeration, and temperature (26 ± 2°C); the water in all containers was completely replaced every 72 h. During the assay animals were periodically weighted and molting was registered. At the end of the assay hemolymph of each juvenile was withdrawn, and then they were sacrificed by cryoanesthesia to dissect hepatopancreas and muscle for determination of lipid and protein levels. Besides, the gills were fixed in Bouin solution for histological analysis. No significant differences were observed between control and groups exposed to DCF neither in weight gain nor in hepatosomatic index or energy reserves levels (p< 0,05). The percentage of molting as well as the time between molts did not show significant differences in exposed groups compared to the control group (p< 0,05). However, the osmolarity in hemolymph was significantly lower (p=0.021) comparing both DCF concentrations to the control. Moreover, the percentage of gills presenting melanization significant increased (p=0.011) in both DCF concentrations, with respect to control. Together, these results suggest a probably gill disfunction caused by diclofenac, which had been barely reported previously. We are currently looking for other pathologies on C. quadricarinatus gills, also analyzing the hemolymphatic components involved with the change in osmolarity.