DNA damage, acetylcholinesterase activity, and hematological responses in rainbow trout exposed to the organophosphate malathion

• Published in: Ecotoxicology and environmental safety Vol. 182; p. 109311
• Main Authors: Alavinia, Seyed Jalil, Mirvaghefi, Alireza, Farahmand, Hamid, Rafiee, Gholamreza, Alavinia, Seyed Jamal, Shiry, Nima, Moodi, Saeed
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 30.10.2019
• Subjects: Alkaline comet assay; Malathion; Pesticide biomarker; Rainbow trout; Recovery treatment; Malathion; Pesticide biomarker; Alkaline comet assay; Recovery treatment; Rainbow trout
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2019.05.081

Effects of sub-lethal concentrations (0 (control), 0.009, 0.014, and 0.023 ppm) of the organophosphate insecticide “malathion” to rainbow trout (Oncorhynchus mykiss) after the determination of LC50-96 h value (0.093 ppm) were evaluated. Changes in biomarkers of neurotoxicity (acetylcholinesterase (AChE) activity), genotoxicity (DNA damage), and hematological parameters (red (RBC) and white (WBC) blood cell count, hemoglobin (Hb), hematocrit (Hct), mean cell hemoglobin (MCH), mean cell volume (MCV), and mean cell hemoglobin concentration (MCHC)) were assessed for a 15-day exposure. A significant time- and dose-dependent reduction in AChE activities of gill, muscle, brain, and liver tissues was found. However, the AChE activity was less affected by malathion concentration than by exposure time. DNA damage of erythrocytes at different malathion concentrations increased by increasing the experimental time up to the fourth day. A decrease in the count of WBC, RBC, and Hct and an increase in the number of MCH and MCV were observed by increasing malathion exposure dose and time (p < 0.05). An increase in the malathion concentration and exposure time significantly resulted in a decrease in Hb and an increase in MCHC. A significant improvement in AChE activity; DNA damage; and RBC, Hb, Hct, MCV, and MCH indices was detected during a 30-day recovery period, but the WBC count changed insignificantly. The recovery pattern based on 100% water exchange with clean water could be a successful strategy to improve the biomarker responses of rainbow trout habituating in contaminated aquatic environments. •Malathion (MLT) toxicity in Oncorhynchus mykiss showed a dose- and time-dependent pattern.•The genotoxicity, neurotoxicity, and hematology of contaminated fish were assessed.•AChE inhibition rate was determined in various tissues of the fish under MLT-induced pollution.•Recovery in clean water based on 100% water exchange could be a desirable strategy to improve the health of MLT-exposed fish.