Histological and immunohistochemical study of the possible protective effect of folic acid on the methotrexate- induced cardiac muscle toxicity in male albino rats

Introduction: Methotrexate is widely used as a chemotherapeutic agent in cancers, ectopic pregnancies and rheumatic arthritis. Folic acid is found in dark green leafy vegetables. Methotrexate is folic acid antagonist that prevents its conversion to tetrahydro folic acid.Aim: This research aimed to study the protective effect of folic acid on the histological changes produced by methotrexate in cardiac muscles.Materials and Methods: Thirty adult male albino rats were divided into three equal groups. Group I (control group) 10 rats injected intraperitoneally with saline. Group II rats were intraperitoneally injected with methotrexate at a dose of 5mg/kg/day for one month. Group III: were intraperitoneally injected with methotrexate at a dose of (5mg/kg/day) with concomitant oral folic acid at a dose of (0.1mg/kg/day) for one month. After 24 hrs of the last dose, the animals were dissected. Hearts were processed for haematoxyline and eosine stain, immunohistochemical stains and electron microscopic examination.Results: Both degenerative and apoptotic changes were observed in the cardiac muscles in the methotrexte-treated group, these changes were attenuated by administration of folic acid.Conclusion: Folic acid is beneficial to the cardiac muscles during methotrexate treatment and should be used concomitant with methotrexate treatment.