Preventive effects of traditional Chinese (Kampo) medicines on experimental osteoporosis induced by ovariectomy in rats

Preventive effects by traditional Chinese (Kampo) medicines, Unkei-to, Hachimi-jio-gan, and Juzen-taihoto, on the progress of bone loss induced by ovariectomy in rats were investigated for a period of 49 days. The bone mineral density (BMD) of tibia in ovariectomized (OVX) rats decreased by 20% from those in sham-operated (Sham) rats, with the decrease completely inhibited by the administration of any one of these Kampo medicines or 17 beta-estradiol. From scanning electron microscopic (SEM) analyses, the surface of a trabecular bone of tibia in OVX rats had a porous or erosive appearance, whereas that of the same bone in Sham rats was composed of fine particles. The administration of three Kampo medicines and 17 beta-estradiol to OVX rats preserved the fine particle surface of the trabecular bone. These results strongly suggest that any of these three gynecological Kampo medicines is as effective as 17 beta-estradiol in preventing the development of bone loss induced by ovariectomy in rats.