EFFECTS OF LPS AND HYDROGEN PEROXIDE ON CELL VIABILITY AND EXPRESSION OF INFLAMMATORY CYTOKINES IN HUMAN DENTAL PULP CELLS: A PRELIMINARY STUDY

Abstract

This study aimed to evaluate the effects of lipopolysaccharide (LPS) and hydrogen peroxide (H2O2) on cell viability and the expression of inflammatory cytokines in human dental pulp cells (DPCs). DPCs were treated with various concentrations of LPS (20, 50, and 100 µg/mL), 400 µM H2O2, or their combination. Cell viability was assessed using the MTT assay at days 1 and 3, while the expression of IL-1β, IL-6, TNF-α, and IFN-γ was analyzed by RT-qPCR after 24 hours. LPS alone did not significantly affect cell viability, even at higher concentrations, whereas co-treatment with H2O2 markedly reduced viability at both time points. The combination of LPS and H2O2 significantly upregulated the expression of all measured inflammatory cytokines compared to the control group, though differences between LPS alone and the combined treatment were not statistically significant. These findings suggest that H2O2 enhances the inflammatory response initiated by LPS and effectively reduces DPC proliferation, thereby better simulating the in vivo inflammatory microenvironment. Further study is recommended to investigate the expression of inflammatory genes at multiple time points to optimize the use of LPS and H2O2 as inducers in an inflammation model.