Phytoestrogenic effect of Matricaria recutita L. and its relationship with endogenous estrogens on locomotor activity in open field test

There are limited information about phytoestrogenic components on physiological phenomena and their interactions with endogenous estrogens. The aim of this investigation to examined the phytoestrogenic effect of Matricaria recutita L. (MR) and it is relationship with endogenous estrogens on locomotor activity with administration of estrogenic receptors antagonist (tamoxifen) on adult female mice. 49 NMRI adult female mice weighted 32±3 grams in 7 groups (each group was 7 mice) receiving: 1) saline, 2) MR (50 mg/kg), 3) tamoxifen (0.1, 0.5, 0.75 mg/kg, in 3 separate groups), 4) saline + MR, 5) tamoxifen (0.5 mg/kg) +MR were used. Motor activity monitor was used for locomotor activity evaluation. Four locomotors parameters such as fast and slow activity and fast and slow rearing were measured. The results showed that: MR (50 mg/kg) increase significantly the fast activity and slow rearing in female mice and partially the other locomotor parameters. Tamoxifen (0.5 mg/kg) decreased fast and slow activity in female mice and other doses had no effect. Most of locomotor parameters decrease significantly in presence of MR and tamoxifen (0.5 mg/kg). It seems MR affects locomotor activity parameters through the estrogenic receptors, and the presence of this receptors and endogenous estrogens are essential for action of its phytoestrogenic components.