Effects of Cynanchum wilfordii on osteoporosis with inhibition of bone resorption and induction of bone formation.

Cynanchum wilfordii Hemsley has been used for the treatment of musculoskeletal diseases in traditional Republic of Korean medicine. The present study investigated the effects of C. wilfordii water extract (CW) on postmenopausal osteoporosis. Female mice were used and randomly assigned into a normal group and three ovariectomized (OVX) groups: OVX with vehicle (OVX + vehicle); OVX with 17β‑estradiol (E2; 10 µg/kg/day); and OVX with CW (1 mg/kg/day). Oral administration of CW or E2 intraperitoneal injection began 9 weeks after OVX and continued for 3 weeks. Following sacrifice, bone histology, bone mineral density (BMD) and bone mineral content (BMC) of the femur were observed. Serum osteocalcin concentration was analyzed. In addition, the expression levels of osteoprotegerin (OPG) and osterix were evaluated in human osteoblast‑like Saos‑2 cells. In the lateral and medial epicondyles of the CW‑administrated group, dense and well‑formed bone marrow cells with reduced bone marrow pores were observed. CW decreased the number of tartrate resistant acid phosphatase‑positive multinucleated osteoclasts. BMD and BMC were increased following increased serum osteocalcin levels by CW treatment. The expression levels of OPG and osterix were upregulated by CW treatment in vitro. The results suggested that C. wilfordii has an advantageous effect on osteoporosis and possesses the potential to be used in osteoporosis treatment.