Tea polyphenols attenuate liver inflammation by modulating obesity-related genes and down-regulating COX-2 and iNOS expression in high fat-fed dogs

BMC Vet Res. 2020 Jul 8;16(1):234. doi: 10.1186/s12917-020-02448-7.

Abstract

Background: Tea polyphenols (TPs) attenuate obesity related liver inflammation; however, the anti-obesity effects and anti-inflammatory mechanisms are not clearly understood. This study aimed to determine whether the anti-obesity and anti-inflammatory TPs mechanisms associated with cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression levels, and obesity-related gene response in dogs.

Results: Dogs fed TPs displayed significantly decreased (p < 0.01) mRNA expression of tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) compared to dogs that consumed high-fat diet (HFD) alone. TPs significantly (p < 0.01) inhibited COX-2 and iNOS expression level, and decreased liver fat content and degeneration.

Conclusion: These results suggested that TPs act as a therapeutic agent for obesity, liver inflammation, and fat degeneration via COX-2 and iNOS inhibition, with TNF-α, IL-1β, and IL-6 involvement.

Keywords: COX-2 expression; Dog; Inflammatory cytokines; Obesity; Tea polyphenols.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents
  • Camellia sinensis / chemistry*
  • Cyclooxygenase 2 / genetics*
  • Dog Diseases / drug therapy
  • Dogs
  • Gene Expression Regulation, Enzymologic / drug effects*
  • Inflammation / veterinary
  • Liver / drug effects*
  • Nitric Oxide Synthase Type II / genetics*
  • Obesity / drug therapy
  • Obesity / veterinary*
  • Polyphenols / pharmacology*

Substances

  • Anti-Inflammatory Agents
  • Polyphenols
  • Nitric Oxide Synthase Type II
  • Cyclooxygenase 2