Ellagic acid is a compound found widely in strawberries, raspberries, and green tea and has been reported to have anti-oxidant, anti-inflammatory and anti-cancer activities. In previous reports, anti-oxidants induced osteoblast differentiation via the expression of osteogenic genes. This study examined the effect of ellagic acid on osteoblast differentiation using C3H10T1/2 cells. First, a MTT assay was performed to determine the concentration at which ellagic acid does not exhibit cytotoxicity. The cells were treated at a concentration of 3 μM without cytotoxicity. The effects of ellagic acid on the mRNA expression levels of the osteogenic genes in C3H10T1/2 cells were determined by real-time PCR. Ellagic acid increased the expression of bone morphogenetic proteins 2 (BMP2), runt-related transcription factor 2 (Runx2), and alkaline phosphatase (ALP). In addition, ellagic acid induced the protein expression levels of BMP2, distal-less homeobox 5 (Dlx5), and Runx2 according to a western blots assay. Next, a staining assay was performed to evaluate the ALP activity or mineralization. Ellagic acid enhanced both the ALP activity and mineralization. In addition, ellagic acid recovered lipopolysaccharide-induced osteoblast differentiation. These results suggest that ellagic acid may enhance osteoblast differentiation.

Keywords: ellagic acid, osteoblast differentiation, mineralization, Runx2, mesenchymal stem cells