2′-Benzoyloxycinnamaldehyde inhibits nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 cells via regulation of AP-1 pathway

Abstract

Cinnamaldehyde, an active compound of cinnamon, has been reported to exert various biological functions such as anti-inflammatory and anti-tumor activities. Previously, we showed that 2′-hydroxycinnamaldehyde (HCA) has an inhibitory effect on nitric oxide (NO) production through the inhibition of NF-κB signaling. In an effort to find a more effective anti-atherosclerotic agent, here we evaluated the anti-inflammatory effect of 2′-benzoyloxycinnamaldehyde (BCA) in RAW 264.7 murine macrophage cells. We showed that BCA more effectively inhibited NO production than HCA with less cytotoxicity. We also demonstrated that BCA inhibited the lipopolysaccharide (LPS)-induced expression of iNOS in a concentration-dependent manner. Signal transduction studies showed that BCA significantly inhibited the phosphorylation of SAPK/JNK and AP-1-dependent reporter gene activity. LPS-induced expression levels of JunB, c-Jun and c-Fos were also decreased by BCA treatment. Moreover, the LPS-induced DNA binding activity of AP-1 was markedly inhibited by BCA. The direct injection of BCA into mice inhibited the LPS-induced increase in plasma nitrite levels, confirming the anti-inflammatory effect of BCA in vivo. Overall, these observations suggest that BCA has the potential for use as an anti-atherosclerotic agent.