Black Adzuki Bean (Vigna angularis) Attenuates High-Fat Diet-Induced Colon Inflammation in Mice

J Med Food. 2017 Apr;20(4):367-375. doi: 10.1089/jmf.2016.3821.

Abstract

Adzuki beans (Vigna angularis), one of the most important legume crops in East Asia, have been shown to possess potential antioxidant and anti-inflammatory effects in mice. Here, we investigated the effects of black adzuki bean (BAB) on colon inflammation triggered by high-fat diet (HD)-induced obesity in mice. We also isolated lipopolysaccharide (LPS)-stimulated peritoneal macrophages and assessed inflammation-related parameters. We found that BAB decreased the concentrations of LPS and various circulating proinflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in mice with HD-induced obesity. BAB also attenuated changes associated with HD-induced colon inflammation, such as increased expression of proinflammatory cytokines. Moreover, BAB inhibited induction of nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and activation of nuclear factor-kappa B (NF-κB) in the colon. Furthermore, BAB upregulated colon mRNA expression of tight junction-associated proteins such as claudin-1 and Zo-1, as well as mucosal barrier defense promoting genes such as mucin (Muc) 1 and Muc3. BAB also reduced macrophage infiltration into adipose tissue in mice with HD-induced intestinal inflammation. In LPS-stimulated peritoneal macrophages, treatment with BAB significantly decreased TNF-α and NO production, NF-κB activation, and iNOS expression. Our findings indicate that BAB ameliorates HD-induced disorders such as obesity and colitis by improving mucosal barrier protection and reducing endotoxemia, as well as by inactivating NF-κB to decrease the production of proinflammatory cytokines.

Keywords: LPS; Vigna angularis; black adzuki bean; high-fat diet; inflammation; obesity.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / metabolism
  • Cells, Cultured
  • Colitis / chemically induced
  • Colitis / drug therapy*
  • Colon / drug effects*
  • Colon / pathology
  • Cyclooxygenase 2 / metabolism
  • Cytokines / blood
  • Diet, High-Fat
  • Inflammation
  • Lipopolysaccharides / metabolism
  • Macrophages, Peritoneal / drug effects
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Nitric Oxide Synthase Type II / metabolism
  • Obesity / chemically induced
  • Obesity / drug therapy
  • Plant Extracts / pharmacology*
  • Transcription Factor RelA / metabolism
  • Vigna / chemistry*

Substances

  • Anti-Inflammatory Agents
  • Cytokines
  • Lipopolysaccharides
  • Plant Extracts
  • Rela protein, mouse
  • Transcription Factor RelA
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse
  • Ptgs2 protein, mouse
  • Cyclooxygenase 2