Cytotoxic Effects of Flavonol Glycosides and Nonflavonoid Constituents of Epimedium koreanum. on Primary Osteoblasts

Seven flavonol glycosides and four nonflavonoid compounds were isolated from Epimedium koreanum Nakai (Berberidaceae), and their effects on the proliferation of rat osteoblast-like (ROB) cells were evaluated with a mitochondrial activity assay. Both flavonol glycosides and nonflavonoid compounds strongly inhibited the proliferation of primary ROB cells at most concentrations (2.0 × 10 −5 mol/L ∼ 1.0 × 10 −8 mol/L), and a simple structure-function relationship was also found in these compounds. Considering the antiosteoporotic effect of flavonoids in vivo, these results suggest that the flavonoids may enhance the development of osteoblasts through their active metabolites, and the mechanism between proliferation and differentiation of osteoblasts needs to be further studied to fully evaluate the mechanism of E. koreanum in the treatment of osteoporosis.