The Effects of Trans-anethole on the Hypothalamic CGRP and CRH Gene Expression in Rat Model of Stress

Stress is defined as a physiological response to environmental conditions which could cause changes in the level of neuropeptides in the central nervous system. Trans- anethole is the secondary active compound with anti-stress and antioxidant properties. This research investigates the effects of trans-anethole on the hypothalamic CRH and CGRP gene expression in stress model rats.

Twenty male rats weighing 200-220 g were used. Animals were divided into four groups (n=5). The intact control or stress groups received saline. Two stress groups received trans-anethole (150 mg/kg or 250 mg/kg, IP). Thirty minutes following the injection of drugs, animals were subjected to acute immobilization stress for two hours. Then, behavioral tests were performed. The hypothalamic samples were removed. CRH and CGRP gene expression was measured using RT-PCR.

The mRNA levels of CGRP and CRH significantly increased in the stress group compared to those of the control. In rats receiving 150 mg/kg or 250 mg/kg of trans-anethole, the mRNA level of CGRP and CRH decreased significantly compared to that of the stress group. Also, injection of 150 mg/kg or 250 mg/kg of trans-anethole significantly improved the stressful behaviors compared to what happened in the stress group.

Trans-anethole may be considered as a potential anti-stress factor due to its inhibitory effects on the activity of hypothalamic stress pathways such as CRH and CGRP