In
traditional Chinese medicine, the cause of weak bones or bone loss is generally regarded as a result of kidney deficiency. Fructus Cnidii (FC), which is also known as She-Chuang-Zi, is a traditional herb that has been claimed to have kidney warming effects that invigorate Yang. In this study, we tried to determine the bone production-inducing effect of FC on osteoblastic cells in vitro using
osthole, the main component of FC. Osteoblasts were isolated from neonatal Sprague-Dawley rat calvaria using the tissue piece culture method and treated with various concentrations of
osthole ranging from 2.5 to 640 microg/mL, together with a blank control. Cell proliferation,
alkaline phosphatase (ALP) activity, and bone nodules were measured. The cells were examined by
hematoxylin-
eosin staining, the Gomori
Calcium-
Cobalt method and immunofluorescent staining. The 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium
bromide (or MTT) assay, ALP assay, and bone nodule results indicated significantly enhanced osteoblastic proliferation and differentiation at concentrations of
osthole ranging from 40 to 320 microg/mL. Concentrations lower than 40 microg/ mL seemed less effective, and cytotoxicity to osteoblasts was observed at concentrations higher than 320 microg/mL. These results indicate that
osthole is effective at inducing osteoblastic bone formation through the up-regulation of ALP activity. FC is a Chinese herb used to treat lumbar
pain in clinical practice. Further studies concerning the effects and mechanism of
osthole on osteoporotic patients and animals should be performed, as these studies may lead to the development of a
drug treatment for
osteoporosis in the future.