Quercitrin and Taxifolin stimulate osteoblast differentiation in MC3T3-E1 cells and inhibit osteoclastogenesis in RAW 264.7 cells

Flavonoids are natural antioxidants that positively influence bone metabolism. The present study screened among different flavonoids to identify biomolecules for potential use in bone regeneration. For this purpose, we used MC3T3-E1 and RAW264.7 cells to evaluate their effect on cell viability and cell differentiation. First, different doses of chrysin, diosmetin, galangin, quercitrin and taxifolin were analyzed to determine the optimum concentration to induce osteoblast differentiation. After 48 h of treatment, doses >= 100 mu M of diosmetin and galangin and also 500 mu M taxifolin revealed a toxic effect on cells. The same effect was observed in cells treated with doses >= 100 mu M of chrysin after 14 days of treatment. However, the safe doses of quercitrin (200 and 500 mu M) and taxifolin (100 and 200 mu M) induced bone sialoprotein and osteocalcin mRNA expression. Also higher osteocalcin secreted levels were determined in 100 mu M taxifolin osteoblast treated samples when compared with the control ones. On the other hand, quercitrin and taxifolin decreased Rankl gene expression in osteoblasts, suggesting an inhibition of osteoclast formation. Indeed, osteoclastogenesis suppression by quercitrin and taxifolin treatment was observed in RAW264.7 cells. Based on these findings, the present study demonstrates that quercitrin and taxifolin promote osteoblast differentiation in MC3T3-E1 cells and also inhibit osteoclastogenesis in RAW264.7 cells, showing a positive effect of these flavonoids on bone metabolism. (C) 2013 Elsevier Inc. All rights reserved.