Investigation of the effects of hydroalcoholic extract of Zataria multiflora on serum concentration of pituitary-thyroid axis hormones in male wistar rats

Zataria multiflora Boiss is a thymelike plant from the Lamiaceae family. It has some properties such as: disinfectant, antioxidant, antiseptic, antispasmodic, antibacterial activities and decreases blood's pressure, glucose and lipid. This study was performed to investigate the effects of Zataria multiflora Boiss on pituitary – thyroid axis (TSH, T3 and  T4)  hormones in male wistar rats.

48 male wistar rats weighing 200±l0g were divided into six groups of eight: The experimental groups received 100,200,300 and 400 mg/kg/day of hydroalcoholic extract of Zataria multiflora Boiss for 28 days intraperitoneally. The sham group received only 0.2ml distilled water as solvent. Control group received nothing. 24h after the last administration, blood samples were collected and serum of samples was separated.Blood concentration of T3, T4 and TSH were measured by RIA.

TSH, T3 and T4 hormones concentrations showed increase in experimental groups compared with the control group. These increases were significant for both T3 and T4 in experimental groups 3 and 4 compared with control group and for TSH in experimental group 4 compared with control group.

According to the negative feedback mechanism, increased blood concentration of T3 and  T4 decreases TSH. Increased TSH level in this study may be due to effects of different chemical compounds of extract which waste  negative feedback of Hypothalamus-Pituitary-Thyroid Axis or induce resistance in Pituitary gland to not decrease TSH. Performing additional studies, Zataria multiflora extract can be used in hypothyroidism treatment.