Inhibitory effect of Thai propolis on human osteoclastogenesis.

Abstract

Avulsed teeth should be immediately replanted into the socket or otherwise kept in a physiologic storage medium to maintain periodontal ligament cell viability. A previous study has demonstrated that Thai propolis extract can maintain viability of human periodontal ligament cells. However, root resorption by osteoclasts often occurs when the avulsed teeth are replanted. The aim of this study was to determine the inhibitory effect of Thai propolis extract on human osteoclastogenesis in vitro. Human peripheral blood mononuclear cells were isolated for osteoclast precursors and cultured in the presence or absence of various non-toxic concentrations of propolis extract, as determined by the alamarBlue® assay, during in vitro induction of osteoclastogenesis. Osteoclast formation was examined by tartrate-resistant acid phosphatase staining, actin ring formation, and real-time polymerase chain reaction. The resorption pit assay was performed to determine osteoclast function. Non-toxic concentrations of propolis extract suppressed osteoclast formation by significantly decreasing the percentages of tartrate-resistant acid phosphatase-positive multinuclear cells and the ratios of cells with F-actin ring formation (P<.01) in a dose-dependent fashion. Expression of several osteoclast-specific genes was significantly downregulated by propolis in a dose-dependent manner (P<.05). The percentages of resorption areas on dentin slices were significantly decreased by propolis (P<.05). Thai propolis can inhibit human osteoclast formation and function, which may be beneficial for prevention of root resorption following replantation of avulsed teeth.