Background: Pomegranate is a medical plant with antioxidant effects. The aim of the study was to investigate the effect of pomegranate juice on pituitary- thyroid axis in adult male rats.

Materials and methods: In this experimental study, 50 adult male rats with mean weight body of 200±20 gr were divided in to 5 groups of 10 rat each: control, sham, and three experimental groups which received in minimal pomegranate juice (3ml per day), medium (6ml per day), and maximal amounts (9ml per day), respectively, for 10 days using gavage method. One day after the last gavage, the blood sample collected by bloodletting from the heart. After preparing serum, the level of T3, T4, and TSH hormones were measured using ELISA method.

Results: Mean body weight in experimental groups didn't show any significant difference in comparison with control and sham groups. Serum levels of T3 hormone in groups receiving maximum dose of pomegranate juice showed significant decrease compared to control and sham groups. Serum level of T4 hormone in experimental groups received pomegranate juice showed significant decrease compared to control and sham groups. Serum level of TSH hormone in minimum dose of pomegranate juice showed significant increase compared to control and sham groups.

Conclusion: Pomegranate juice reduced pituitary-thyroid axis activity in adult male rats.

Keywords: Pomegranate juice, T3, T4, TSH, Rat.