Dietary polyphenols suppress elevated levels of proinflammatory mediators and aromatase in the mammary gland of obese mice

Cancer Prev Res (Phila). 2013 Sep;6(9):886-97. doi: 10.1158/1940-6207.CAPR-13-0140. Epub 2013 Jul 23.

Abstract

In postmenopausal women, obesity is a risk factor for the development of hormone receptor-positive breast cancer driven by estrogen. After menopause, aromatization of androgen precursors in adipose tissue is a major synthetic source of estrogen. Recently, in mouse models and women, we identified an obesity-inflammation-aromatase axis. This obesity-induced inflammation is characterized by crown-like structures (CLS) consisting of dead adipocytes encircled by macrophages in breast white adipose tissue. CLS occur in association with NF-κB activation, elevated levels of proinflammatory mediators, and increased aromatase expression. Saturated fatty acids released from adipocytes have been linked to obesity-related white adipose tissue inflammation. Here we found that stearic acid, a prototypic saturated fatty acid, stimulated Akt-dependent activation of NF-κB resulting in increased levels of proinflammatory mediators [TNF-α, interleukin (IL)-1β, COX-2] in macrophages leading, in turn, to the induction of aromatase. Several polyphenols (resveratrol, curcumin, epigallocatechin gallate) blocked these inductive effects of stearic acid. Zyflamend, a widely used polyherbal preparation that contains numerous polyphenols, possessed similar suppressive effects. In a mouse model of obesity, treatment with Zyflamend suppressed levels of phospho-Akt, NF-κB binding activity, proinflammatory mediators, and aromatase in the mammary gland. Collectively, these results suggest that targeting the activation of NF-κB is a promising approach for reducing levels of proinflammatory mediators and aromatase in inflamed mouse mammary tissue. Further investigation in obese women is warranted.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Retracted Publication

MeSH terms

  • Adipocytes / cytology
  • Adipocytes / metabolism
  • Adipose Tissue / cytology
  • Adipose Tissue / metabolism
  • Animals
  • Aromatase / chemistry*
  • Aromatase / metabolism
  • Blotting, Western
  • Cells, Cultured
  • Diet*
  • Disease Models, Animal
  • Electrophoretic Mobility Shift Assay
  • Female
  • Humans
  • Inflammation / drug therapy*
  • Inflammation / metabolism
  • Inflammation / pathology
  • Inflammation Mediators / antagonists & inhibitors*
  • Inflammation Mediators / metabolism
  • Mammary Glands, Human / drug effects*
  • Mammary Glands, Human / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Obese
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • Obesity / drug therapy
  • Obesity / metabolism
  • Obesity / pathology
  • Phosphatidylinositol 3-Kinases / genetics
  • Phosphatidylinositol 3-Kinases / metabolism
  • Polyphenols / administration & dosage*
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / drug effects

Substances

  • Inflammation Mediators
  • NF-kappa B
  • Polyphenols
  • RNA, Messenger
  • Aromatase
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt