Mulberry fruit prevents LPS-induced NF-κB/pERK/MAPK signals in macrophages and suppresses acute colitis and colorectal tumorigenesis in mice

Sci Rep. 2015 Nov 30:5:17348. doi: 10.1038/srep17348.

Abstract

Here, we investigated the impact of mulberry fruit (MBF) extracts on lipopolysaccharide (LPS)-induced inflammatory responses in RAW 264.7 macrophages, and the therapeutic efficacy of MBF diet in mice with dextran sulfate sodium (DSS)-induced acute colitis and MUC2(-/-) mice with colorectal cancer. In vitro, LPS-induced nitric oxide (NO) production was significantly inhibited by MBF extracts via suppressing the expression of proinflammatory molecules, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-1 beta (IL-β) and IL-6. Particularly, a dose-dependent inhibition on LPS-induced inflammatory responses was observed following treatment with MBF dichloromethane extract (MBF-DE), in which linoleic acid and ethyl linolenate were identified as two active compounds. Moreover, we elucidated that MBF-DE attenuated LPS-induced inflammatory responses by blocking activation of both NF-κB/p65 and pERK/MAPK pathways. In vivo, DSS-induced acute colitis was significantly ameliorated in MBF-fed mice as gauged by weight loss, colon morphology and histological damage. In addition, MBF-fed MUC2(-/-) mice displayed significant decrease in intestinal tumor and inflammation incidence compared to control diet-fed group. Overall, our results demonstrated that MBF suppressed the development of intestinal inflammation and tumorgenesis both in vitro and in vivo, and supports the potential of MBF as a therapeutic functional food for testing in human clinical trials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cell Transformation, Neoplastic / drug effects
  • Cell Transformation, Neoplastic / genetics
  • Cell Transformation, Neoplastic / metabolism
  • Colitis / drug therapy
  • Colitis / etiology
  • Colitis / metabolism
  • Colitis / pathology
  • Colorectal Neoplasms / etiology
  • Colorectal Neoplasms / metabolism
  • Cytokines / genetics
  • Cytokines / metabolism
  • Dextran Sulfate / adverse effects
  • Dietary Supplements
  • Disease Models, Animal
  • Extracellular Signal-Regulated MAP Kinases / metabolism*
  • Fruit / chemistry*
  • Gene Expression Regulation / drug effects
  • Inflammation Mediators / metabolism
  • Linoleic Acid / chemistry
  • Linolenic Acids / chemistry
  • Lipopolysaccharides / adverse effects
  • Lipopolysaccharides / immunology
  • Macrophages / drug effects*
  • Macrophages / metabolism*
  • Mice
  • Mice, Knockout
  • Mitogen-Activated Protein Kinases / metabolism*
  • Morus / chemistry*
  • Mucin-2 / deficiency
  • NF-kappa B / metabolism*
  • Nitric Oxide / biosynthesis
  • Phosphorylation
  • Plant Extracts / administration & dosage
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Protein Transport
  • Signal Transduction / drug effects*

Substances

  • Cytokines
  • Inflammation Mediators
  • Linolenic Acids
  • Lipopolysaccharides
  • Mucin-2
  • NF-kappa B
  • Plant Extracts
  • Nitric Oxide
  • Dextran Sulfate
  • Linoleic Acid
  • Extracellular Signal-Regulated MAP Kinases
  • Mitogen-Activated Protein Kinases
  • ethyl linolenate