Objective: In this study, it was aimed to investigate the potential protective effects of fish oil (FO) against methotrexate (MTX)-induced kidney and liver damage.

Materials and Methods: In rats divided into four groups (n=7); the control group was given corn oil by gavage for 14 days and physiological saline intraperitoneally (i.p.) on the third day, FO group was given 1000 mg/kg FO by gavage for 14 days and i.p. physiological saline on the third day, MTX group was given corn oil by gavage for 14 days and i.p. single dose of 20 mg/kg MTX on the third day, MTX+BY group was given 1000 mg/kg FO by gavage for 14 days and i.p. single dose of 20 mg/kg MTX on the third day. At the end of the experiment, rats were decapitated, their kidneys and livers were preserved at -86 °C, and biochemical measurements were made.

Results: With the administration of MTX, thiobarbituricacid reactive substance (TBARS) levels increased; superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx) and catalase (CAT) activities were decreased compared to the control group. Co-administration of FO with MTX resulted in reduction in TBARS level and increase in GSH, CAT, SOD and GPx activities.

Conclusion: In this study, it was determined that MTX caused oxidative damage in kidney and liver tissues and FO prevented this damage.