Biochemical changes in certain enzymes of Lysapsus limellium (Anura: Hylidae) exposed to chlorpyrifos

• Enzyme biomarkers were used in digestive tissues of Lysapsus limellum in a rice field.
• CPF degradation in water samples decreased at 168 h in the rice field.
• AChE and CbE were inhibited in stomach and liver at 24 and 168 h, and in intestine only at 24 h in rice field frogs.
• GST was inhibited in intestine at 24 h and in stomach and liver at 168 h in rice field frogs.
• CAT activity decreased in stomach and liver at 168 h, and only in intestine at 24 and 168 h in rice field frogs.

Different enzyme biomarkers (AChE: acetylcholinesterase, CbE: carboxylesterase, GST: glutathione-S-transferase, CAT: catalase) were measured in digestive tissues of Lysapsus limellum frogs collected from a rice field (RF: chlorpyriphos sprayed by aircraft) and a non-contaminated area (RS: reference site), immediately (24 h) and 168 h after aerial spraying with chlorpyrifos (CPF). CPF degradation was also searched in water samples collected from RF and RS, and found that insecticide concentration was reduced to≈6.78% of the original concentration in RF at 168 h. A significant reduction of AChE and CbE activities was detected in L. limellum from RF in stomach and liver at 24 and 168 h, and in intestine only at 24 h, with respect to RS individuals. CAT activity decreased in intestine of L. limellum from RF 24 h and 168 h after exposure to CPF, whereas GST decreased in that tissue only at 24 h. In stomach and liver, a decrease was observed only at 168 h in both CAT and GST. The use of biomarkers (AChE, CbE, GST, and CAT) provides different lines of evidences for ecotoxicological risk assessment of wild frog populations at sites contaminated with pesticides.