Effects of a herbal extract on the bone density, strength and markers of bone turnover of mature ovariectomized rats

For many decades, the Chinese have been using herbal medications to treat bone diseases. To examine effects of an extract of ten medicinal herbs on estrogen deficiency bone loss, ten-month-old female rats were randomly divided into three groups: ovariectomized (OVX), OVX treated with herbs (OVX-M) 4 ml/day by gavage, and OVX treated with estrogen (OVX-E) 10 mg subcutaneously (s.c.) twice per week. The bone mineral density (BMD) of the left femur (fBMD), spine (sBMD) and global body (gBMD) were measured at baseline and at 4, 8 and 12 weeks using a Hologic QDR 2000 dual-energy X-ray densitometer. Tibial strength was tested using the Instron Model 5566 electro-mechanical testing machine. The urinary pyridinoline creatinine ratio (Pyd/Cr), deoxypyridinoline creatinine ratio (Dpd/Cr), plasma alkaline phosphatase (ALP), calcium (CA), phosphorus (P) and albumin (ALB) were also determined. Uterine weight was determined at 12 weeks. The results showed that percent changes of fBMD in the OVX (n = 9), OVX-E (n = 8) and OVX-M (n = 8) rats at the 12-week time point were -11.8 ± 4.6c, 1.8 ± 3.1a, -7.6 ± 1.9abc (p <0.05-0.001, a: vs. OVX, b: vs. OVX-E, c: vs. baseline); sBMD were -10.7 ± 4.6c, -0.3 ± 5.5a, -5.9 ± 3.5abc; and gBMD were -4.8 ± 2.3c, 0.1 ± 2.4a, -2.7 ± 2.6abc, respectively. Further, the tibia maximum breaking stress and flexural modulus of elasticity in OVX-M rats (295 ± 33a, 18194 ± 3264a) were significantly higher (p <0.005-0.001) than that in OVX rats (189 ± 83, 10309 ± 4930), and similar to OVX-E rats (298 ± 35a, 18766 ± 2620a). Additionally, the herbal extract reduced the urinary Pyd/Cr, Dpd/Cr and plasma ALP increment followed OVX and was not associated with a rise in uterine weight. In conclusion, the herbal extract demonstrated a therapeutic effect to inhibit bone resorption and to reduce estrogen-dependent bone loss without uterine stimulation. It may have potential as a new approach in treating and preventing postmenopausal osteoporosis (PMOP).Read More: http://www.worldscientific.com/doi/abs/10.1142/S0192415X0300076X