Boldine’s Effect on Cell Viability in Macrophages Stimulated with Lipopolysaccharide from Porphyromonas spp.

Objectives: To evaluate the effect of boldine on cell viability and toxicity in human macrophages stimulated with lipopolysaccharide (LPS) of Porphyromonas spp.
Methods: LPS strains were purified by a modified TRIzol extraction protocol. Macrophage-differentiated THP-1 cells were stimulated with LPS from either P. gingivalis, P. endodontalis or E. Coli in the presence of different concentrations of boldine (0- 500 µg/ml). Viable cells were counted in an automated cell counter and cytotoxicity was determined through MTT assay. Statistical analysis was carried out through Stata v12.
Results: THP-1 cells stimulated with boldine at 500 µg/ml evidenced morphology changes suggestive of cell death. The cell viability analysis significantly dropped when using 500 µg/ml of boldine whereas a borderline significant decrease was observed in the group with boldine 50 µg/ml compared with controls (undiferenciated cells). A difference in the cytotoxicity was obtained when comparing the control group with the group stimulated with P. gingivalis at 25 µg/ml (p<0.05). There was no significant difference between the groups stimulated with P. endodontalis LPS.
Conclusions: High concentrations of boldine (500 µg/ml) can affect the viability of macrophages. Boldine over a certain concentration (25 µg/ml) in the presence of P. gingivalis could induce macrophage cytotoxicity. More studies are needed regarding the action of boldine on human macrophages in the presence of LPS from oral pathogens.