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.