Deog-Gon Kim

Anti-Inflammatory Effects of Sinapic Acid through the Suppression of Inducible Nitric Oxide Synthase, Cyclooxygase-2, and Proinflammatory Cytokines Expressions via Nuclear Factor-κB Inactivation

To investigate the anti-inflammatory potential of sinapic acid as well as the underlying mechanism involved, we studied the inhibitory effect of sinapic acid on the production of pro-inflammatory mediators in vitro and then evaluated its in vivo anti-inflammatory effect. Sinapic acid inhibited lipopolysaccharide (LPS)-induced nitric oxide (NO), prostaglandin E 2 (PGE 2), tumor necrosis factor (TNF)-alpha, and interleukin (IL)-1beta production in a dose-dependent manner. Consistent with these findings, sinapic acid inhibited LPS-induced expressions of inducible nitric oxide synthase (iNOS) and cyclooxygase (COX)-2 at the protein levels, and iNOS, COX-2, TNF-alpha, and IL-1beta mRNA expression in RAW 264.7 macrophages, as determined by Western blotting and reverse-transcribed polymerase chain reaction, respectively. Sinapic acid suppressed the LPS-induced activation of nuclear factor-kappaB (NF-kappaB), a transcription factor pivotal necessary for pro-inflammatory mediators, such as iNOS, COX-2, TNF-alpha, and IL-1beta. This effect was accompanied by a parallel reduction of the nuclear translocation of p65 and p50 NF-kappaB subunits, as well as IkappaB-alpha degradation and phosphorylation. The effects of sinapic acid on acute phase inflammation were investigated on serotonin- and carrageenan-induced paw edema and compared with indomethacin (10 mg/kg, p.o.) or ibuprofen (100 mg/kg, p.o.). Maximum inhibitions of 34.2 and 44.5% were observed at a concentration of 30 mg/kg for serotonin- and carrageenan-induced paw edema, respectively. These results suggest that the suppressions of the expressions of iNOS, COX-2, TNF-alpha, and IL-1beta via NF-kappaB inactivation are responsible for the anti-inflammatory effects of sinapic acid.

Inhibitory effects of casticin on migration of eosinophil and expression of chemokines and adhesion molecules in A549 lung epithelial cells via NF-κB inactivation

ETHNOPHARMACOLOGICAL RELEVANCE The fruits of Vitex rotundifolia L. have long been used for the treatment of inflammation of the respiratory tract in East Asia. AIM To determine if casticin, one of the constituents of Vitex rotundifolia L., has anti-allergic and anti-inflammatory effects in asthma. MATERIALS AND METHODS The in vitro anti-inflammatory activity of casticin was studied in A549 human type II-like epithelial lung cells using an eotaxin inhibition assay. Additionally, its effects on eotaxin, regulated on activation normal T cell expressed and secreted (RANTES), vascular cell adhesion molecule (VCAM)-1, and inter-cellular adhesion molecule (ICAM)-1 expression were investigated by real time-polymerase chain reaction (real time-PCR). The inhibition of nuclear factor κB (NF-κB) activity in the presence of casticin was determined by analyzing confocal microscopy images of fluorescence immunocytochemical analysis while the suppression of inhibitory κB (IκB)-α phosphorylation was studied using Western blot analysis. Finally, the inhibitory effect of casticin on eosinophil migration toward prestimulated A549 cell media was measured using the human eosinophilic leukemia cell line. RESULTS AND DISCUSSION Casticin significantly suppressed eotaxin production in cytokine activated A549 lung epithelial cells. Casticin also suppressed the mRNA expression levels of eotaxin, RANTES, VCAM-1, and ICAM-1, which subsequently contributed to the inhibition of eosinophil migration. Furthermore, casticin inhibited IκB-α phosphorylation and nuclear translocation of p65 in A549 cells. CONCLUSION Casiticin inhibited the eosinophil migration and activity of chemokines and adhesion molecules involved in the inflammatory process of asthma by suppressing the NF-κB pathway. These results suggest that casticin has the potential for use in the treatment of allergic asthma.