effects of alcoholic extract of myrtus communis l. on the hypothalamic-pituitary-thyroid axis in rats

Background: myrtus communis leaves have the potential to affect thyroid hormone functions. objectives: in this study, the effects of hydroalcoholic extract of m. communis on the hypothalamus-pituitary-thyroid axis and histological changes were studied. materials and methods: in this experimental study, 40 male rats were divided in 5 groups (n = 8): control, sham, and three experimental groups which received the extract of m. communis leaves in a minimal (0.75 mg/kg), medium (1.5 mg/kg) and maximal amounts (3 mg/kg), respectively. at the end of the 15th day blood samples were collected to measure triiodothyronine (t3), thyroxine (t4) and thyroid-stimulating hormone (tsh) and to study thyroid gland tissue results: serum levels of t4 and tsh in groups receiving maximum dose of the extract showed a significant decrease compared to sham group (p < 0.05). conclusions: it is probable that some compounds in the alcoholic extract of m. communis leaves may be cause changes in serum tsh concentration and thyroid hormones.