The effect of green tea catechins as novel antithyroid compounds in hyperthyroid rabbits induced by levothyroxine sodium

This study was undertaken to extract catechins from green tea leaves. It is to show the curative effect of green tea catechins after a short term daily oral administration for 8 days (200 mg?kg b.w) on serum level of thyroid hormones and thyroid-stimulating hormone in hyperthyroid rabbits induced by levothyroxine sodium (L-T4). Rabbits were divided into 4 groups, 6 rabbits in each group. Group 1 animals received only 3 ml normal saline orally as control group, group 2 was treated with (L-T4) 0.3 mg?kg b.w as hyperthyroidic. The 3rd group hyperthyroidic rabbits were post-treated with green tea catechins extract (200 mg?k g b.w) while the 4th group hyperthyroidic rabbits were post-treated with carbimazole (5 mg ? kg b.w). The results indicated high significantly increased (p< 0.001) in serum level of total triiodothyronine (TT3), total thyroxine (TT4) and high significantly stimulating hormone in hyperthyroid rabbits