(+)-Catechin Attenuates NF-κB Activation Through Regulation of Akt, MAPK, and AMPK Signaling Pathways in LPS-Induced BV-2 Microglial Cells

Am J Chin Med. 2015;43(5):927-52. doi: 10.1142/S0192415X15500548.

Abstract

(+)-Catechin is a flavanol that possesses various health and medicinal values, which include neuroprotection, anti-oxidation, antitumor and antihepatitis activities. This study investigated the modulatory effects of (+)-catechin on the lipopolysaccharides (LPS)-stimulated BV-2 cells. (+)-catechin attenuated LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and inhibited microglial NO and ROS production. Additionally, (+)-catechin suppressed the production of tumor necrosis factor-α (TNF-α) and interleukin (IL)-6, while augmenting IL-4. (+)-catechin attenuated LPS-induced nuclear factor-κB (NF-κB) p65 nuclear translocation via the inhibition of IκB-α phosphorylation. Moreover, (+)-catechin blocked the activation of Akt and its inhibition was shown to play a crucial role in LPS-induced inflammation in BV-2 microglial cells. (+)-catechin also attenuated the LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK1/2), and p-38 mitogen activated protein kinases (p38 MAPK) and specific inhibitors of ERK1/2 (UO126) and p38 MAPK (SB202190) subsequently down-regulated the expression of the proinflammatory mediators iNOS and COX-2. Further mechanistic study revealed that (+)-catechin acted through the amelioration of the LPS-induced suppression of adenosine monophosphate-activated protein kinase (AMPK) activity. Taken together, our data indicate that (+)-catechin exhibits anti-inflammatory effects in BV-2 cells by suppressing the production of proinflammatory mediators and mitigation of NF-κB through Akt, ERK, p38 MAPK, and AMPK pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases / metabolism*
  • Active Transport, Cell Nucleus / drug effects
  • Animals
  • Anti-Inflammatory Agents*
  • Catechin / pharmacology*
  • Cell Line
  • Inflammation Mediators / metabolism
  • Interleukin-4 / metabolism
  • Interleukin-6 / metabolism
  • Lipopolysaccharides / adverse effects
  • Mice
  • Microglia / cytology
  • Microglia / metabolism*
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • NF-kappa B / metabolism*
  • Phosphorylation / drug effects
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction / drug effects*
  • Tumor Necrosis Factor-alpha / metabolism
  • p38 Mitogen-Activated Protein Kinases / metabolism*

Substances

  • Anti-Inflammatory Agents
  • Inflammation Mediators
  • Interleukin-6
  • Lipopolysaccharides
  • NF-kappa B
  • Tumor Necrosis Factor-alpha
  • Interleukin-4
  • Catechin
  • Proto-Oncogene Proteins c-akt
  • Mitogen-Activated Protein Kinase 3
  • p38 Mitogen-Activated Protein Kinases
  • AMP-Activated Protein Kinases