BACKGROUND AND OBJECTIVE: Thyroid disorders are relatively common diseases throughout the world. According to chemical drugs side effects, this study aimed to investigate the effect of the pituitary-thyroid axis function VAC extract in adult male rats.

METHODS: In this study, 50 adult male rats were divided into control and experimental groups received doses of 50, 100 and 200 mg / kg VAC extracts. All prescribed for 30 days and was conducted by gavage. In the end, after collecting blood samples from animals to measure T3, T4 and TSH hormones, thyroid removed and after preparing tissue sections follicles were counted and compared.

FINDINGS: The results showed that extracts of Vitex decreased TSH and increased T4 hormone in the order of 0.72±0.1 and 3.66±0.30 in the control group to 0.27±0.03 and 5.76±0.47 in the group receiving dose of 200 mg/kg and increases T3 of 71.20 ± 4.05 in control group to 90.60±5.63 and 88.8±5.39 at doses of 100 and 200 mg/kg. In addition, extracts of Vitex decreased body weight of 310±4.5 in the control group to 286.66±13.95, 265.83±13.77 and 276.83±10.13 at doses 50, 100 and 200 mg/kg (p<0.05). Moreover, Vitex extract increased the total number of follicles of 17.19±2.44 in the control group to 31.54±2.9 and 34.66±1.5 and 36.77±3.45 and active follicles of 13.15±2.04 in the control group to 28.83±2.46, 28.77±2.98 and 34.38±2.84 in experimental groups (p<0.01).

CONCLUSION: The results of this study demonstrated that Vitex extract significantly increased thyroid hormones and reduced TSH and body weight