Effects of Rosemary and curcumin leaves extract on Histophysiological aspects of rats with Hypothyroidism.

Background: Hypothyroidism is a common disease characterized by low thyroid hormone levels. Carbimazole is an anti-thyroid medication that is commonly used in patients with hyperthyroidism. Carbimazole is a prodrug; after absorption, it is converted to the active form, methimazole, which prevents the thyroid peroxidase enzyme from iodinating and coupling tyrosine residues on thyroglobulin, hence reducing the production of the thyroid hormones T3 and T4. Objective: This study aims to identify the effects of aqueous extracts of rosemary leaves and curcumin in regulating thyroid hormones T3, T4, and TSH after inducing hypothyroidism with carbimazole in female rats. Methodology: In an experimental study, a total of 90 healthy adult female rats were assigned randomly to three main groups (30 rats per group) according to the type of treatment and periods. Examined the physiological changes in the thyroid gland of several animals by serological analysis of thyroid hormones after the end of the period (7 weeks) to ensure the induction of hypothyroidism in rats. The remaining animals were then treated with aqueous extracts of rosemary leaves and curcumin at concentrations of 200 mg/kg and 150 mg/kg, respectively, for a period of 8 weeks. Results: The present study showed significant differences (p<0.05) between the two carbimazole concentrations (2.5 mg/kg and 5mg/kg) in their effects on levels of TSH, T3, and T4 at 7 weeks, where the higher concentration of carbimazole recorded the highest effect on T3, T4, and TSH levels. The rosemary (200 mg/kg) and curcumin (150mg/kg) extracts recorded the highest increase in levels of T3 and T4 in 8 weeks compared to the positive control (hypothyroidism), and decreased the levels of TSH in 8 weeks than hypothyroidism. Conclusions: It can be concluded that different concentrations of rosemary and curcumin aqueous extraction are beneficial in treating patients with hypothyroidism by regulating levels of TSH, T3, and T4 that were conducted with microscopic examination of thyroid tissues revealed mostly moderate to marked histopathological changes from epithelial degeneration comparison with normal histology of thyroid gland ranged from cellular to vacuolar degeneration and necrosis of follicles and colloid material filled their lumens of follicles after treatment with rosemary and curcumin.