Anti-inflammatory effect of essential oil and its constituents from fingered citron (Citrus medica L. var. sarcodactylis) through blocking JNK, ERK and NF-κB signaling pathways in LPS-activated RAW 264.7 cells

Food Chem Toxicol. 2013 Jul:57:126-31. doi: 10.1016/j.fct.2013.03.017. Epub 2013 Mar 26.

Abstract

We investigated the composition of essential oil from fingered citron (Citrus medica L. var. sarcodactylis) (FCEO) peels by GC-MS and its anti-inflammatory effects on lipopolysaccharide (LPS) - stimulated mouse macrophage (RAW 264.7) cells. Fifteen compounds, representing 98.97% of the essential oil, were tentatively identified; the main constituents were limonene (52.44%) and γ-terpinene (28.41%). FCEO significantly inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) by suppressing the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2, respectively. Additionally, FCEO suppressed the production of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6. FCEO attenuated LPS-induced nuclear factor-κB (NF-κB) activation via inhibition of inhibitor κB-α phosphorylation. Furthermore, FCEO blocked activation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) but not that of p38 mitogen-activated protein kinase. These results indicate that FCEO inhibits LPS-stimulated inflammation by blocking the NF-κB, JNK, and ERK pathways in macrophages, and demonstrate that FCEO possesses anti-inflammatory properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Cell Line / drug effects
  • Citrus / chemistry*
  • Cyclohexane Monoterpenes
  • Cyclohexenes / pharmacology
  • Cytokines / metabolism
  • Dinoprostone / metabolism
  • JNK Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Limonene
  • Lipopolysaccharides / pharmacology*
  • MAP Kinase Signaling System / drug effects
  • Macrophages / drug effects
  • Macrophages / metabolism
  • Mice
  • Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • Mitogen-Activated Protein Kinases / metabolism
  • Monoterpenes / pharmacology
  • NF-kappa B / antagonists & inhibitors
  • NF-kappa B / metabolism
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase Type II / metabolism
  • Oils, Volatile / pharmacology*
  • Plant Oils / pharmacology
  • Signal Transduction / drug effects*
  • Terpenes / pharmacology

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Cyclohexane Monoterpenes
  • Cyclohexenes
  • Cytokines
  • Lipopolysaccharides
  • Monoterpenes
  • NF-kappa B
  • Oils, Volatile
  • Plant Oils
  • Terpenes
  • Nitric Oxide
  • gamma-terpinene
  • Limonene
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinases
  • Dinoprostone