Oxidative DNA damage of lambda-cyhalothrin in model vertebrate organism

Pesticides, widely used for insect control in agriculture, public health, and veterinary medicine, are usually present as pollutants in aquatic environments. After contamination of water bodies, pesticides cause adverse effects on non-target organisms and long-term problems in the ecosystem. Lambda-cyhalothrin (LCH) is a chemical compound belonging to the family of synthetic pyrethroids (type II) and is an active ingredient in several insecticides. This study investigated the toxic effects (DNA damage) of LCH exposure on zebrafish for 24 and 72 h. After zebrafish (Danio rerio) were obtained commercially, acclimated, and adapted to laboratory conditions. They were randomly selected, transferred to the experimental aquariums (their average height is 2.51 ± 0.49 cm long, 10 L aquarium size of 10x20x35), and exposed to 0.1 mg/L LCH concentrations for 24 and 72 h. There was also a control and a solvent control group in the study, and whole body tissues of zebrafish were analyzed for 8-hydroxy-2-deoxyguanosine (8-OhdG) determination (ng/100 mg tissue), using an Agilent LC-MS/MS with electrospray ionization in positive ion mode. It was observed that the whole-body 8-OHdG tissue values were significantly increased in the group exposed to LCH for 72 h (9.82 ± 1.44) compared with the control group (6.60 ± 1.78, p = .004). These results suggest that LCH could lead to oxidative DNA damage by causing an increase in 8-OHdG activities in zebrafish, one of the aquatic ecosystem model organisms, indicating that it may also cause undesirable effects on other non-target species.