OP partially protects dental pulp stem cells DPSCs from MG-induced inflammation. The supernatants were collected, and IL-1β (a), IL-6 (b) and IL-8 (b) release were measured by ELISA. MG caused a significant increase in the levels of IL-1β (a) and IL-6 (b), while it dramatically reduced RAGE mRNA expression (c). When DPSCs were pretreated with OP, MG effects on both interleukins (a,b) and RAGE level (c) were reverted to that of control. Histograms indicate the means ± SD of three different cultures, each of which was tested in triplicate. * p < 0.05 and ** p < 0.01, significantly different from control untreated cells. ° p < 0.05, compared to MG-treated cells.