Pomegranate extract improves a depressive state and bone properties in menopausal syndrome model ovariectomized mice

Pomegranate is known to contain estrogens (estradiol, estrone, and estriol) and show estrogenic activities in mice. In this study, we investigated whether pomegranate extract is effective on experimental menopausal syndrome in ovariectomized mice. Prolongation of the immobility time in forced swimming test, an index of depression, was measured 14 days after ovariectomy. The bone mineral density (BMD) of the tibia was measured by X-ray absorptiometry and the structure and metabolism of bone were also analyzed by bone histomorphometry. Administration of pomegranate extract (juice and seed extract) for 2 weeks to ovariectomized mice prevented the loss of uterus weight and shortened the immobility time compared with 5% glucose-dosed mice (control). In addition, ovariectomy-induced decrease of BMD was normalized by administration of the pomegranate extract. The bone volume and the trabecular number were significantly increased and the trabecular separation was decreased in the pomegranate-dosed group compared with the control group. Some histological bone formation/resorption parameters were significantly increased by ovariectomy but were normalized by administration of the pomegranate extract. These changes suggest that the pomegranate extract inhibits ovariectomy-stimulated bone turnover. It is thus conceivable that pomegranate is clinically effective on a depressive state and bone loss in menopausal syndrome in women.