Diclofenac activates antioxidant defenses and affects ovarian growth in the freshwater shrimp Macrobrachium borellii

Abstract

Ovigerous females of the freshwater shrimp Macrobrachium borellii were exposed to three sublethal concentrations (0.01, 0.1, and 1 mg/L) of diclofenac sodium salt, for 74 d, in order to measure several variables related to both reproductive success and oxidative stress. Although no differences (p > 0.05) were noted in either the egg incubation time or the postlarvae survival, the number of hatched postlarvae (actual fecundity) decreased to some extent, together with a low percentage of abnormal larvae. At the end of the assay, the ovarian size of re-maturating shrimps exposed to 1 mg/L of diclofenac was significantly (p < 0.05) higher than that of controls, showing an acceleration of ovarian growth by the effect of this drug. Taken together, these results showed no evident increase of the reproductive output. Concerning oxidative stress, both the reduced glutathione level and total antioxidant capacity were enhanced without altering glutathione-S-transferase activity and lipid peroxidation. Concomitantly, no damage to the hepatopancreas structure was observed in females. We conclude that diclofenac caused an imbalance in gonadal growth, likely by affecting the endocrine control exerted by prostaglandins, while oxidative stress could be efficiently controlled by the induction of antioxidant defenses.