Profiling cytokine levels in chlorhexidine and EGCG-treated odontoblast-like cells.

Objective: To screen the effect of two compounds, chlorhexidine diacetate (CHX) and epigallocatechin-gallate (EGCG), on the levels of cytokines produced by odontoblast-like cells (MDPC-23).

Methods: Cells were seeded at 24h and 48h with serial dilution of the compounds to determine cell metabolic activity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay (n=3). Cells with no compound treatment were used as control (Ctr). For the highest equal non-cytotoxic compound dilution tested at 48h cell treatment, total protein concentration was measured using a Pierce bicinchoninic acid (BCA) assay (n=3), and expression of 23 cytokines was analyzed using the Bio-Plex cytokine assay (n=2). Data were analyzed by one-way ANOVA and Tukey's test (α=5%).

Results: The MTT assay revealed that at 24h and 48h, CHX and EGCG did not reduce cell metabolic activity at concentrations of 2.5-20μM (CHX) and 2.5-160μM (EGCG), respectively (p>0.05). At 48h, total protein levels were consistent across all groups for 20μM compound dilution (Ctr: 1.04mg/mL; CHX: 0.98mg/mL; and EGCG: 1.06mg/mL). At 20μM dilution, both CHX and EGCG significantly increased the secretion of IL-1β, IL-10, IL-12, KC, MIP-1α, IFN-γ and IL-6 (p<0.05). Treatment with CHX significantly increased secretion of IL-4 and RANTES (p<0.05).

Treatment: with EGCG significantly increased Eotaxin secretion (p<0.05). Both CHX and EGCG significantly decreased secretion of IL-17 (p<0.05). GM-CSF and TNF-α did not present significant change in secretion after treatment with either CHX or EGCG (p>0.05).

Significance: Both CHX and EGCG modulate secretion of various inflammatory and anti-inflammatory mediators in odontoblastic cells.