Epigallocatechin-3-gallate ameliorates lipopolysaccharide-induced acute lung injury by suppression of TLR4/NF-κB signaling activation

Braz J Med Biol Res. 2019;52(7):e8092. doi: 10.1590/1414-431X20198092. Epub 2019 Jun 19.

Abstract

Acute lung injury (ALI) is a serious clinical syndrome with a high rate of mortality. The activation of inflammation is well-recognized as a vital factor in the pathogenesis of lipopolysaccharide (LPS)-induced ALI. Therefore, suppression of the inflammatory response could be an ideal strategy to prevent ALI. Epigallocatechin-3-gallate (EGCG), mainly from green tea, has been shown to have an anti-inflammatory effect. The aim of the study was to explore whether EGCG alleviates inflammation in sepsis-related ALI. Male BALB/C mice were treated with EGCG (10 mg/kg) intraperitoneally (ip) 1 h before LPS injection (10 mg/kg, ip). The results showed that EGCG attenuated LPS-induced ALI as it decreased the changes in blood gases and reduced the histological lesions, wet-to-dry weight ratios, and myeloperoxidase (MPO) activity. In addition, EGCG significantly decreased the expression of pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in the lung, serum, and bronchoalveolar lavage fluid, and alleviated the expression of TLR-4, MyD88, TRIF, and p-p65 in the lung tissue. In addition, it increased the expression of IκB-α and had no influence on the expression of p65. Collectively, these results demonstrated the protective effects of EGCG against LPS-induced ALI in mice through its anti-inflammatory effect that may be attributed to the suppression of the activation of TLR 4-dependent NF-κB signaling pathways.

MeSH terms

  • Acute Lung Injury / chemically induced
  • Acute Lung Injury / prevention & control*
  • Animals
  • Catechin / administration & dosage
  • Catechin / analogs & derivatives*
  • Disease Models, Animal
  • Lipopolysaccharides
  • Male
  • Mice
  • Mice, Inbred BALB C
  • NF-kappa B / drug effects*
  • Signal Transduction / drug effects
  • Toll-Like Receptor 4 / drug effects*

Substances

  • Lipopolysaccharides
  • NF-kappa B
  • Toll-Like Receptor 4
  • Catechin
  • epigallocatechin gallate