Ameliorative Role of Marjoram Against Ionizing Radiation-Induced Biochemical and Histological Changes in Thyroid Gland in Male Rats

The present study was designed to determine the possible protective effects of marjoram, grey green leaf, against gamma radiation-induced oxidative damage in thyroid gland of male albino rats. Marjoram (100 mg/kg/day) was given to rats via gavages for 30 consecutive days prior exposure to irradiation (4.5 Gy) and the last dose of marjoram was administered 24 hr before irradiation. Thyroid gland was taken for histological study and blood samples for biochemical analysis on the 7th and 15 th day post-irradiation. In the irradiated group, the histological observations of thyroid gland sections showed distortion of the thyroid follicles together with apparent swelling of the follicular cells, vacuolated cytoplasm and ill-defined cell boundaries of the follicular epithelium. Biochemical analysis in the blood showed significant decrease in serum tri-iodothyronine (T3) and thyroxine (T4). Also, a significant decrease was observed in serum superoxide dismutase (SOD) and catalase (CAT), and blood glutathione (GSH). Treatment with marjoram (100 mg/kg) was found to offer significant protection against gamma radiation induced toxicity in thyroid gland tissues which was evident by improved status of most parameters under investigation. These results suggest that marjoram could increase the antioxidant defence systems of thyroid gland and may protect from adverse effects of whole body gamma radiation.