In the present study, the effects of coenzyme Q10 (CoQ10), which is widely used in daily life, on the methotrexate (MTX)-induced hepatotoxicity, which is widely used today in malignancies and autoimmune diseases, were examined. Twenty-four female Wistar albino rats were divided into four groups. The group 1 ( = 6) was given 1 mL corn oil by oral gavage (p.o.) during seven days. Group 2 was given 20 mg/kg intraperitoneal (i.p.) MTX only on the first day of the experiment. Group 3 was given 20 mg/kg (i.p.) MTX on the first day of the experiment and 100 mg/kg CoQ10 dissolved in 1 mL corn oil were given by oral gavage during seven days, and group 4 was given 100 mg/kg CoQ10 dissolved in 1 mL corn oil by oral gavage during seven days. At the end of experiment, all animals were euthanized under anesthesia. In the liver tissue, histopathologic analysis on the hematoxylin and eosin (H&E), Masson trichrome, and periodic acid Schiff (PAS) stained sections, apoptotic analysis (% Annexin V positivity) by flow cytometry, and biochemical analysis for oxidative stress markers (GSH, CAT, and TBARS) was performed. According to histopathological analysis, apoptosis, concession, fibrosis, and inflammatory cell infiltration increased in the MTX group and those results significantly decreased in the MTX + CoQ10 groups. As an interesting result, fatty degeneration and TBARS elevation were observed in the MTX + CoQ10 group. As a result, although CoQ10 has protective effects on MTX-induced hepatotoxicity, fatty degeneration due to the combined usage of MTX and CoQ10 should be investigated with further studies.
