Patchoulene Epoxide Isolated from Patchouli Oil Suppresses Acute Inflammation through Inhibition of NF-κB and Downregulation of COX-2/iNOS.

Jia-Li Liang,Han-Bin Chen,Yan-Feng Huang,Yu-Hong Liu,Jiang-Tao Zhou,Zi-Ren Su,Janis Ya-Xian Zhan,Zhen-Biao Zhang,Qi-Duan Wu,Yao-Xing Dou,Jia-Zhen Wu

doi:10.1155/2017/1089028

Abstract

According to the GC-MS analysis, compositional variation was observed between samples of patchouli oil, of which an unknown compound identified as patchoulene epoxide (PAO) was found only in the long-stored oil, whose biological activity still remains unknown. Therefore, the present study aimed to evaluate the potential anti-inflammatory activity with three in vivo inflammatory models: xylene-induced ear edema, acetic acid-induced vascular permeability, and carrageenan-induced paw edema. Further investigation into its underlying mechanism on carrageenan-induced paw edema was conducted. Results demonstrated that PAO significantly inhibited the ear edema induced by xylene, lowered vascular permeability induced by acetic acid and decreased the paw edema induced by carrageenan. Moreover, PAO markedly decreased levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), prostaglandin E2 (PGE2), and nitric oxide (NO), but increased levels of interleukin-4 (IL-4) and interleukin-10 (IL-10). PAO was also shown to significantly downregulate the protein and mRNA expressions of cyclooxygenase-2 (COX-2) and inducible nitric-oxide synthase (iNOS). Western blot analysis revealed that PAO remarkably inhibited p50 and p65 translocation from the cytosol to the nucleus by suppressing IKKβ and IκBα phosphorylation. In conclusion, PAO exhibited potent anti-inflammatory activity probably by suppressing the activation of iNOS, COX-2 and NF-κB signaling pathways.

Highlights

Acute inflammation is an initial protective response of an immunological defense system to harmful stimuli such as microbial infections, allergens, and physical injuries [1], which is characterized by redness, swelling, heat, and arteriosclerosis [2]
The total ion GC-mass spectrometry (MS) chromatograms of fresh and stale patchouli oil were shown in Figures 1(a) and 1(b), respectively
In the gas chromatography-mass spectrometry (GC-MS) spectrum of stale patchouli oil, an unknown compound with a content of 5.344% was observed at 9.996 min

Summary

Introduction

Acute inflammation is an initial protective response of an immunological defense system to harmful stimuli such as microbial infections, allergens, and physical injuries [1], which is characterized by redness, swelling, heat, and arteriosclerosis [2]. Pathogenesis of acute inflammation involves various signaling molecules such as COX-2, iNOS, and NF-κB [3]. Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most commonly prescribed therapeutics for inflammatory diseases. They become increasingly controversial due to their side effects like gastric lesions [5]. In recent decades, more and more attention has been paid to seeking alternatives with fewer side effects, and Mediators of Inflammation a number of natural compounds derived from traditional Chinese herbs such as curcumin and quercetin [6] have been found to have great anti-inflammatory potential

Methods

Results

Discussion

Conclusion