Aqueous extract of Gracilaria tenuistipitata suppresses LPS-induced NF-κB and MAPK activation in RAW 264.7 and rat peritoneal macrophages and exerts hepatoprotective effects on carbon tetrachloride-treated rat

PLoS One. 2014 Jan 27;9(1):e86557. doi: 10.1371/journal.pone.0086557. eCollection 2014.

Abstract

In addition to the previous investigations of bioactivity of aqueous extract of the edible Gracilaria tenuistipitata (AEGT) against H2O2-induced DNA damage and hepatitis C virus replication, the purpose of this study is to evaluate the potential therapeutic properties of AEGT against inflammation and hepatotoxicity using lipopolysaccharide (LPS)-stimulated mouse RAW 264.7 cells, primary rat peritoneal macrophages and carbon tetrachloride (CCl4)-induced acute hepatitis model in rats. AEGT concentration-dependently inhibited the elevated RNA and protein levels of inducible nitric oxide synthase and cyclooxygenase-2, thereby reducing nitric oxide and prostaglandin E2 levels, respectively. Moreover, AEGT significantly suppressed the production of LPS-induced proinflammatory cytokines, including interleukin (IL)-1β, IL-6 and tumor necrosis factor-α. These inhibitory effects were associated with the suppression of nuclear factor-kappa B activation and mitogen-activated protein kinase phosphorylation by AEGT in LPS-stimulated cells. In addition, we highlighted the hepatoprotective and curative effects of AEGT in a rat model of CCl4-intoxicated acute liver injury, which was evident from reduction in the elevated serum aspartate aminotransferase and alanine aminotransferase levels as well as amelioration of histological damage by pre-treatment or post-treatment of AEGT. In conclusion, the results demonstrate that AEGT may serve as a potential supplement in the prevention or amelioration of inflammatory diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Carbon Tetrachloride / adverse effects
  • Cell Line
  • Chemical and Drug Induced Liver Injury / drug therapy*
  • Enzyme Activation / drug effects*
  • Gracilaria / chemistry*
  • Macrophages / metabolism
  • Magnetic Resonance Spectroscopy
  • Mice
  • Mitogen-Activated Protein Kinases / metabolism*
  • NF-kappa B / metabolism*
  • Oligonucleotides / genetics
  • Phytotherapy / methods*
  • Plant Extracts / pharmacology*
  • Plant Extracts / therapeutic use
  • Rats

Substances

  • NF-kappa B
  • Oligonucleotides
  • Plant Extracts
  • Carbon Tetrachloride
  • Mitogen-Activated Protein Kinases

Grants and funding

This work was funded by grants from the National Science Council of Taiwan (NSC 101-2311-B-037-002-MY3 and NSC 101-2622-B-037-001-CC3), Kaohsiung Medical University Research Foundation, Taiwan (KMUER014) and The Department of Health, Executive Yuan, Taiwan (DOH102-TD-C-111-002). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.