Effects of water extracts of Davallia formosana on ovariectomized mice

Abstract

ObjectiveThe Taiwanese native fern, Davallia formosana, is used to treat bone diseases in traditional Chinese medicine, but, very few animal tests to verify. To study how this fern and its active components alter bone metabolism. MethodsThe effects of low and high doses of D. formosana water extracts (DFW, 50 and 200 mg/(kg·d)) and (-)-epicatechin-3-O-D-allopyranoside isolates of DFW (ECAP, 0.06 and 2.5 mg/(kg·d)) on protein levels of important indicators of osteoclast and osteoblast activities were examined. Ovariectomized mice were used as a model of osteoporosis. Bone morphogenetic protein 2 (BMP-2), collagen 1 (COL-1), alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), and osteopontin (OPN) were analyzed using western blotting of femur tissue. Interleukin (IL)-1β and tumor necrosis factor (TNF)-α were measured in the serum, and hematoxylin and eosin staining were used to assess bone morphology. ResultsTreatment with DFW or ECAP significantly induced BMP-2, COL-1, ALP, RUNX2, OCN, and OPN protein expression, indicating stimulation of osteogenesis. The treatments also reduced IL-1β and TNF-α expression, indicating inhibition of osteoclastogenesis. In histological examinations, mice treated with DFW or ECAP had more bone trabeculae. The results demonstrate that DFW and ECAP inhibit osteoclast differentiation and promote osteoblast differentiation, and effectively ameliorate ovariectomy (OVX)-induced osteoporosis. ConclusionECAP is a major component of DFW, which may have therapeutic potential for the treatment of diseases associated with excessive osteoclastic and insufficient osteogenic activity. ECAP may not be the specific active molecule because it is unstable in the stomach. However, the major active molecule needs to be confirmed using a relevant pharmacological model.