Effects of Rhizoma Drynariae Cataplasm on Fracture Healing in a Rat Model of Osteoporosis

BACKGROUND Osteoporosis is an increasingly prevalent disease characterized by decreased bone mass and deterioration of the bone microstructure, which contribute to increased fragility and subsequent fragility fractures, especially in elderly individuals. Rhizoma Drynariae (DRE) is among the most frequently used herbal medicines for the treatment of osteoporosis. Transdermal delivery is a proven novel pathway for drug treatment and has several advantages over traditional drug delivery routes. MATERIAL AND METHODS Female Sprague-Dawley osteoporotic fracture model rats were divided into 3 groups: the control group, the DRE (90 mg/kg/day) group and the DRE cataplasm (containing 30 mg DRE, administered at right femur site daily) group. At 3 and 6 weeks after operation, we performed x-ray, histological, and biomechanical analyses, and evaluated bone marrow density of the femur. RESULTS Treatment with DRE increased callus formation and bone union compared with the control group. Moreover, DRE enhanced bone strength at the femoral diaphysis in the osteoporotic fractures in rats by increasing the ultimate load and stiffness compared with the control group. Furthermore, DRE restored the trabecular bone mineral density in the femur compared with the control group. DRE cataplasm application further enhanced the therapeutic effects against osteoporotic fracture in this rat model. CONCLUSIONS DRE cataplasm application might be useful against osteoporotic fracture.