Biol. Pharm. Bull. 28(10) 1879—1885 (2005)

is characterized by a reduction in bone mass and microarchitectural deterioration of bone tissue, resulting in skeletal fragility and susceptibility to fractures especially the wrist, spine and hip. Current approach for the design of anti-osteoporotic drug is directed along two basic processes of bone remodeling including agents that targeting at preventing bone resorption (estrogen, calcitonin, bisphosphonates, calcium, vitamin D, raloxifene) as well as agents that stimulating bone formation (fluoride, anabolic steroids). Among them, estrogen replacement therapy (ERT) was used to be a popular regime for prevention and treatment of postmenopausal osteoporosis. However, recent evidence suggest that ERT is associated with increased risk of development of breast, ovarian and endometrial cancers. In addition, the most frequently used anti-osteoporotic drugs are developed in affluent countries and the costs are too high to benefit a large population in the developing or even the developed countries for prevention and treatment of osteoporosis. Thus, alternative approach for management of osteoporosis is needed. Chinese herbal medicine has been widely used in clinical practice to treat bone disease for thousands of years and will undoubtedly continue to be used as a cost-effective alternative to commercial pharmaceutical products by traditional users. The genus Sambucus, widely distributed in Europe, Asia and North Africa, has been used as folk medicine in analgesic, antivirus, anti-inflammatory, homoeostatic, and diuretic drugs which act on bruises, fractures and edema. Li et al. reported that extract of the stem of Sambucus sieboldiana (SS) inhibited bone resorption in organ culture. Oral administration of ethyl acetate (EtOAc) fraction of SS to ovariectomized (OVX) rat prevented the decrease in bone mineral density of the lumber vertebra. These results suggested that EtOAc fraction of SS could suppress bone resorption in vitro and in vivo and that Sambucus is a herb with potential for prevention and treatment of osteoporosis. In China stem and ramulus of Sambucus williamsii HANCE (SWH) has been used for centuries for treatment of inflammation and bone fractures and joint diseases. In the present study, we aimed to investigate in vivo effects of herba SWH extract on postmenopausal osteoporosis using OVX rat model. Biochemical markers of bone turnover, bone strength and bone mineral density changes would be determined. Our results indicated that orally administrated SWH extracts can decrease urinary calcium excretion and bone turnover rate in OVX rats, resulting in positive effects on bone biomechanical strength mineral density. With the recent discovery of receptor activator of NF-kB ligand (RANKL)–RANK interaction, the role of osteoblast in osteoclast differentiation is now clearly defined. Binding of RANKL (the membrane associated factor) secreted by osOctober 2005 Biol. Pharm. Bull. 28(10) 1879—1885 (2005) 1879