Ethyl ferulate protects against lipopolysaccharide-induced acute lung injury by activating AMPK/Nrf2 signaling pathway

Acta Pharmacol Sin. 2021 Dec;42(12):2069-2081. doi: 10.1038/s41401-021-00742-0. Epub 2021 Aug 20.

Abstract

Ethyl ferulate (EF) is abundant in Rhizoma Chuanxiong and grains (e.g., rice and maize) and possesses antioxidative, antiapoptotic, antirheumatic, and anti-inflammatory properties. However, its effect on lipopolysaccharide (LPS)-induced acute lung injury (ALI) is still unknown. In the present study, we found that EF significantly alleviated LPS-induced pathological damage and neutrophil infiltration and inhibited the gene expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) in murine lung tissues. Moreover, EF reduced the gene expression of TNF-α, IL-1β, IL-6, and iNOS and decreased the production of NO in LPS-stimulated RAW264.7 cells and BMDMs. Mechanistic experiments revealed that EF prominently activated the AMPK/Nrf2 pathway and promoted Nrf2 nuclear translocation. AMPK inhibition (Compound C) and Nrf2 inhibition (ML385) abolished the beneficial effect of EF on the inflammatory response. Furthermore, the protective effect of EF on LPS-induced ALI was not observed in Nrf2 knockout mice. Taken together, the results of our study suggest that EF ameliorates LPS-induced ALI in an AMPK/Nrf2-dependent manner. These findings provide a foundation for developing EF as a new anti-inflammatory agent for LPS-induced ALI/ARDS therapy.

Keywords: AMPK; Nrf2; acute lung injury; ethyl ferulate; inflammation; lipopolysaccharide.

MeSH terms

  • AMP-Activated Protein Kinases / metabolism
  • Acute Lung Injury / chemically induced
  • Acute Lung Injury / complications
  • Acute Lung Injury / drug therapy*
  • Acute Lung Injury / pathology
  • Animals
  • Anti-Inflammatory Agents / therapeutic use*
  • Caffeic Acids / therapeutic use*
  • Cytokines / metabolism
  • Gene Knockout Techniques
  • Inflammation / complications
  • Inflammation / drug therapy
  • Lipopolysaccharides
  • Lung / drug effects
  • Lung / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mutation
  • NF-E2-Related Factor 2 / genetics
  • NF-E2-Related Factor 2 / metabolism
  • Neutrophil Infiltration / drug effects
  • Neutrophils / drug effects
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase Type II / antagonists & inhibitors
  • RAW 264.7 Cells
  • Signal Transduction / drug effects*

Substances

  • Anti-Inflammatory Agents
  • Caffeic Acids
  • Cytokines
  • Lipopolysaccharides
  • NF-E2-Related Factor 2
  • Nfe2l2 protein, mouse
  • Nitric Oxide
  • ethyl ferulate
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse
  • AMP-Activated Protein Kinases