Effect of propolis on human fibroblasts from the pulp and periodontal ligament

Propolis, a flavonoid-rich product of honey comb, exhibits antibacterial and anti-inflammatory properties. In this study, we examined the tolerance of fibroblasts of the periodontal ligament (PDL) and dental pulp to propolis and compared with that of calcium hydroxide in vitro. Cells from human dental pulp and PDL were obtained from healthy third molars and subjected to various concentrations of propolis (0-20 mg/ml) and calcium hydroxide (0-250 mg/ml). The cell viability after propolis treatment was analyzed by crystal violet staining of the cells followed by spectrophotometric analysis. Data revealed that exposure of PDL cells or pulp fibroblasts to 4 mg/ml or lower concentrations of propolis resulted in >75% viability of cells. On the contrary, calcium hydroxide 0.4 mg/ml was cytotoxic and <25% of the cells were found to be viable. Further investigations may find propolis to be a possible alternative for an intracanal antimicrobial agent.