Zanthoxylum piperitum D.C. (ZP) peels has been used as a natural spice and herb medicine for hypertension reduction, for strokes, and for its anti-bacterial and anti-oxidant activity. However, the anti-inflammatory mechanisms employed by ZP have yet to be completely understood. In this study, we elucidate the anti-inflammatory mechanism of ZP in lipopolysaccharide (LPS)-induced RAW264.7 cells. We evaluated the effects of ZP in LPS-induced levels of inflammatory cytokines, prostaglandin E2 (PGE2), and caspase-1 using ELISA. The expression levels of inflammatoryrelated genes, including cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS), were assayed by Western blot analysis. We elucidated the effect of ZP on nuclear factor (NF)-κB activation by means of a luciferase activity assay. The findings of this study demonstrated that ZP inhibited the production of inflammatory cytokine and PGE2 and inhibited the increased levels of COX-2 and iNOS caused by LPS. Additionally, we showed that the anti-inflammatory effect of ZP arises by suppressing the activation of NF-κB and caspase-1 in LPS- induced RAW264.7 cells. These results provide novel insights into the pharmacological actions of ZP as a potential candidate for development of new drugs to treat inflammatory diseases.

Abstract
Introduction
Materials and Methods
    Reagents
    Preparation of ZP
    Cell culture
    MTT assay
    Cytokine assay
    PGE2 assay
    Measurement of nitrite (NO) concentration
    Western blot analysis
    Luciferase reporter gene assay
    Caspase-1 activity assay
    Statistical analysis
Results
    ZP inhibits production of TNF-α and IL-6 in LPS-induced RAW264.7 cells
    ZP inhibits production of PGE2 and expression of COX-2 in LPS-induced RAW264.7 cells
    ZP inhibits production of NO and expression of iNOS in LPS-induced RAW264.7 cells
    ZP inhibits NF-κB activation in LPS-induced RAW 264.7 cells
    ZP inhibits caspase-1 activation in LPS-induced RAW 264.7 cells
Discussion
References

• Yun-Hee Choi(Department of Oriental Medicine and Healthcare, Wonkwang Digital University)
• Noh-Yil Myung(Department of Oriental Medicine and Healthcare, Wonkwang Digital University) Corresponding author