Carthamus tinctorius flower extract prevents H2O2‐induced dysfunction and oxidative damage in osteoblastic MC3T3‐E1 cells

The flowers of Carthamus tinctorius L. (Compositae) have been widely used for enhancing blood circulation and postmenopausal disorder in women. In the present study, the potential protective effects of C. tinctorius flower extract (CFE) against reactive oxygen species (ROS) induced osteoblast dysfunction were investigated using osteoblastic MC3T3‐E1 cells. The osteoblast function was assessed by measuring alkaline phosphatase activity, collagen content, calcium deposition, and RANKL production, and the oxidative status was assessed by measuring intracellular lipid peroxidation, and protein oxidation in osteoblastic MC3T3‐E1 cells. A significant reduction in the alkaline phosphatase activity, collagen, and calcium deposition and an increase in the production of receptor activator of nuclear factor‐kB ligand (RANKL) were observed after 0.3 mM H₂O₂ addition. The H₂O₂‐induced alterations were prevented by pre‐incubating the osteoblasts with 2–10 μg/ml CFE for 48 h. When the oxidative stress was induced by H₂O₂, the increased production of protein carbonyl and malondialdehyde was also reduced at the same CFE concentration. These results demonstrate that C. tinctorius flower can act as a biological antioxidant in a cell culture experimental model and protect osteoblasts from oxidative stress‐induced toxicity. Copyright © 2009 John Wiley & Sons, Ltd.