Effect of Brazilian green and brown propolis on human pulp cells and bacteria involved in primary endodontic infection: Ex Vivo study

Objectives: This study evaluated the antibacterial effects and impact of Brazilian green propolis (BGP) and brown propolis (BBP) on human dental pulp fibroblasts (HDPF). Design: HDPF were seeded in 96-well plates (10,000 cells/well) and exposed to BGP (5, 10, 50 mu g/mL), BBP (5, 10, 50 mu g/mL), 0.5 % dimethyl sulfoxide, 0.018 % carbamide peroxide, 10 mu g/mL tumor necrosis factor alpha (TNF-alpha), and Dulbecco's Modified Eagle Medium (control). Cell viability (methyl-thiazol-tetrazolium assay), reactive oxygen species (ROS, DCFH-DA probe), nitric oxide (NO; Griess reagent), and cell morphology (scanning electron microscopy) were analyzed. Wound healing was assessed at 0, 24, and 48 h. The minimum inhibitory concentration/minimum bactericidal concentration was determined. Dunn's rank-sum test (5 % significance) was used. Results: BGP and BBP exhibited high cytocompatibility, maintained cell viability, and did not induce NO production (p > 0.05). ROS production in the TNF-alpha group differed considerably from that in the other groups. Regarding the antibacterial effect at concentrations <= 100 mu g/mL, BGP was effective against P. micra, while BBP was effective against seven bacterial species. Conclusions: BGP and BBP demonstrated high cytocompatibility and absence of ROS and NO production, with BGP promoting greater HDPF stimulation and BBP exhibiting superior antibacterial activity.