Polydatin Modulates Inflammatory Cytokine Expression in Lipoteichoic Acid-Stimulated Human Dental-Pulp Stem Cells

Gram-positive bacteria are responsible for initiating dental caries. In this process, lipoteichoic acid (LTA), which is expressed on Gram-positive bacteria cell walls, binds to the dental pulp cells, triggering an immune response, followed by inflammation and eventually pulp necrosis. Polydatin is a polyphenolic compound that has been shown to modulate inflammatory mediators in a manner favorable to healing. The purpose of this study was to assess levels of expression of the most prevalent cytokines in the inflamed pulp after polydatin treatment of LTA-stimulated human dental-pulp stem cells (hDPSCs). LTA-stimulated hDPSCs were treated with polydatin in three different concentrations (0.01 µM, 0.1 µM, and 1 µM). Interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α) levels were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were quantified. Treatment with all concentrations of polydatin significantly decreased IL-6 and TNF-α levels as evaluated by ELISA and RT-qPCR, respectively. In addition, a significant reduction was observed in IL-8 levels of mRNA and in ELISA, with 0.01 µM and with 1 µM of polydatin in RT-qPCR. On the other hand, IL-10 levels increased with all of the concentrations. In conclusion, polydatin treatment of LTA-stimulated hDPSCs modulated inflammatory cytokine production by suppressing IL-6, IL-8, and TNF-α levels while elevating IL-10 levels.