Abstract
This study examined the anti-inflammatory effects of 70% ethanol crude extract of immature Citrus unshiu fruits (ICE) and its solvent fractions in LPS-stimulated RAW 264.7 cells. In addition, we analyzed the active compounds related to suppression of inflammation. It was found that the ethyl acetate (EtOAc) fraction showed the highest level of inhibition of NO production, and this inhibitory activity was concentration-dependent. Moreover, the EtOAc fraction not only inhibited TNF-α and IL-6 production but also inhibited iNOS and COX-2 protein expression. Furthermore, inhibition of NF-κB activity and MAPK phosphorylation was also observed. In addition, β-sitosterol, campesterol and isoferulic acid were identified as major anti-inflammatory components in the EtOAc fraction. These results suggested that the EtOAc fraction of immature C. unshiu fruit extract exerts anti-inflammatory effects by inhibiting NF-κB and MAPK signaling pathways, and that this fruit could be used as a natural anti-inflammatory material.