The effects of Nigella sativa L. ethanolic extract on thyroid function in normal and alloxan-induced diabetic rats

Abstract

Context: Nigella sativa, (black cumin seeds) compounds display a remarkable array of biochemical, immunological, and pharmacological actions, including bronchodilatory, antibacterial, hypotensive, immunopotentiating, hypoglycemic, and antitumor activity. Aims : The aim of the present study was to evaluate effects of Nigella sativa L. ethanolic extract (NSE) on the thyroid function test in normal and alloxan-induced diabetic Wistar albino rats. Settings and Design: Experimental study. Materials and Methods: Alloxan monohydrate was injected intraperitoneally at single dose of 150 mg/kg body weight to induce diabetes. Twenty Wistar albino rats were divided into four groups: NSE-treated normal, diabetic, NSE-treated diabetic, and control. NSE was administered daily orally by gavage at a dose of 1 g/kg body weight for 14 days. Serum concentration of TSH, T 4 , T 3 were measured by radioimmunoassay on day 7 th and 14 th . Statistical Analysis Used: Data are expressed as the mean ± S.E.M. For statistical analysis, ANOVA was used. Results: NSE induced a significant increase in the T 3 serum concentration on both day 7 th and 14 th in the diabetic rats and increase T 4 serum concentration on day 14 th in the normal rats. Conclusions: The results revealed that daily oral administration of Nigella sativa L. ethanolic extract (1 g/kg Bwt.) for 14 days significantly increased the serum concentration of T 4 in the normal Wistar albino rats. On the other hand the results revealed that treatment returned the serum concentration of T 3 to the normal level in the Alloxan-induced diabetic rats. Further work is suggested for evaluating the effect of Nigella sativa L. on the serum concentration of thyroid hormones to elucidate the possible mode of action.