Histopathological and hormonal study of subacute toxicity of celecoxib on thyroid gland in rats

ABSTRACT

Celecoxib, a selective cyclo-oxygenase 2 inhibitor, was developed as a potential treatment for rheumatoid arthritis and osteoarthritis. It has good bioavailability and distribution and excellent safety profile in preclinical models. Although the effects of several NSAlDs on thyroid function tests have been investigated, a little was reported in literature about the toxic effect of celecoxib on thyroid functions. This study is one of fewer studies that investigated the subacute toxicity of celecoxib on thyroid function tests as well as on the morphology of thyroid gland in male rats. In this study, the doses of 10, 50 and 75 mg/kg/day of celecoxib were given to male rats orally for 28 days. At the end of the study, serum total triiodothyronine [T[3]], total thyroxine [T[4]] and thyroid stimulating hormone [TSH] levels of rats were analyzed by enzyme immunoassay [EIA] test kits. Thyroid glands of male rats were examined histopathologically. While there was no change in serum T[3] and T[4] of celecoxib-treated rats, there were a significant decrease in serum TSH levels of rats treated with 50, 75 mg/kg/day celecoxib for 28 days compared with those of control rats. In histopathological examinations, celecoxib-related changes were found in thyroid glands of celecoxib-treated rats [50 and 75 mg/kg for 28 days] showing lymphocytic infiltration, distorted acini, degenerated, exhausted colloid and interstitial hemorrhage. These changes in thyroid hormones and histopathology were dose-dependent