3.2 β-damascone suppressed LPS-induced activation of DCs
We evaluated the effects of β-damascone on LPS-induced activation of DCs by analyzing the cytokine expression levels and cell surface expression levels of APC-related molecules in BMDCs. As shown in Figure 2A , β-damascone apparently reduced the mRNA levels of IL-6, IL-12p40, and TNF-α in DCs, which was increased following LPS stimulation, in a dose-dependent manner. The concentrations of these inflammatory cytokines in the culture media of LPS-stimulated DCs were also decreased in the presence of β-damascone (Figure 2B ), suggesting that suppression of the LPS-induced transactivation of cytokine genes by β-damascone was reflected in protein release. In addition, flow cytometric analysis revealed that LPS-induced upregulation of MHC class II and CD86 was also suppressed in β-damascone-treated DCs (Figure 2C ). We also confirmed that the increased phosphorylation of IκB in LPS-stimulated DCs was reduced by the pretreatment with β-damascone (Figure 2D ). These results indicate that β-damascone exhibits a suppressive effect on LPS-induced inflammatory responses and antigen presentation activity in DCs.