Anti-osteoporotic effect of the dried root of Rehmannia glutinosa in ovariectomized rats

Abstract

Dried root of Rehmannia glutinosa is a kidney-tonifying herbal medicine with a long history of safe use for treatment of joint diseases in traditional Korean medicine. However, the anti-osteoporotic effect of dried root of R. glutinosa has not yet been reported in vivo model. In the present study was conducted to investigate anti-osteoporotic effect of dried root of R. glutinosa in ovariectomized (OVX) rat model of postmenopausal bone loss. Dried root of R. glutinosa was extracted with 70% ethanol for 3h at 80°C in a reflux apparatus. The OVX rats were divided into four groups, which treated by vehicle, 17β-estradiol (10 ug/kg, i.p) and R. glutinosa (100 and 300mg/kg, p.o). All groups were treated for 8 weeks. Body weight and femur and lumbar vertebrae bone mineral density (BMD) were determined weekly. Serum calcium (Ca), phosphorus (P) and alkaline phosphatase (ALP) concentrations were measured by biochemistry analyzer. The treatment with R. glutinosa at 300mg/kg was significantly inhibited BMD decrease in the femur and lumbar by OVX without affecting body and organ weights. Also, R. glutinosa at 300mg/kg for 8 weeks significantly decreased ALP levels compared to OVX control group. These results suggest that dried root of R. glutinosa is effective at preventing bone loss in OVX rats without the influence of hormones such as estrogen.