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 μg/mL), BBP (5, 10, 50 μg/mL), 0.5 % dimethyl sulfoxide, 0.018 % carbamide peroxide, 10 μg/mL tumor necrosis factor alpha (TNF-α), 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-α group differed considerably from that in the other groups. Regarding the antibacterial effect at concentrations ≤ 100 μg/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.