The benzoate plant metabolite ethyl gallate prevents cellular- and vascular-lipid accumulation in experimental models of atherosclerosis

Biochem Biophys Res Commun. 2021 Jun 4:556:65-71. doi: 10.1016/j.bbrc.2021.03.158. Epub 2021 Apr 8.

Abstract

Ethyl gallate (EG) is a well-known constituent of medicinal plants, but its effects on atherosclerosis development are not clear. In the present study, the anti-atherosclerosis effects of EG and the underlying mechanisms were explored using macrophage cultures, zebrafish and apolipoprotein (apo) E deficient mice. Treatment of macrophages with EG (20 μM) enhanced cellular cholesterol efflux to HDL, and reduced net lipid accumulation in response to oxidized LDL. Secretion of monocyte chemotactic protein-1 (MCP-1) and interleukin-6 (IL-6) from activated macrophages was also blunted by EG. Fluorescence imaging techniques revealed EG feeding of zebrafish reduced vascular lipid accumulation and inflammatory responses in vivo. Similar results were obtained in apoE-/- mice 6.5 months of age, where plaque lesions and monocyte infiltration into the artery wall were reduced by 70% and 42%, respectively, after just 6 weeks of injections with EG (20 mg/kg). HDL-cholesterol increased 2-fold, serum cholesterol efflux capacity increased by ∼30%, and the levels of MCP-1 and IL-6 were reduced with EG treatment of mice. These results suggest EG impedes early atherosclerosis development by reducing the lipid and macrophage-content of plaque. Underlying mechanisms appeared to involve HDL cholesterol efflux mechanisms and suppression of pro-inflammatory cytokine secretion.

Keywords: ATP binding Cassette (ABC) transporters; Atherosclerosis; Ethyl gallate; High density lipoproteins (HDL); Macrophage foam-cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / biosynthesis
  • ATP-Binding Cassette Transporters / genetics
  • Animals
  • Apolipoproteins E / deficiency
  • Atherosclerosis / drug therapy*
  • Atherosclerosis / metabolism*
  • Atherosclerosis / pathology
  • Atherosclerosis / prevention & control
  • Benzoates / metabolism*
  • Cholesterol, HDL / blood
  • Cholesterol, HDL / metabolism
  • Cytokines / metabolism
  • Disease Models, Animal
  • Female
  • Foam Cells / cytology
  • Foam Cells / drug effects
  • Foam Cells / immunology
  • Foam Cells / metabolism
  • Gallic Acid / administration & dosage
  • Gallic Acid / analogs & derivatives*
  • Gallic Acid / metabolism
  • Gallic Acid / pharmacology
  • Gallic Acid / therapeutic use
  • Inflammation / drug therapy
  • Inflammation / metabolism
  • Inflammation / prevention & control
  • Inflammation Mediators / metabolism
  • Lipid Metabolism / drug effects*
  • Mice
  • Mice, Inbred C57BL
  • Plants, Medicinal / metabolism*
  • Plaque, Atherosclerotic / drug therapy
  • Plaque, Atherosclerotic / metabolism
  • Plaque, Atherosclerotic / pathology
  • Plaque, Atherosclerotic / prevention & control
  • RAW 264.7 Cells
  • Up-Regulation / drug effects
  • Zebrafish / metabolism

Substances

  • ATP-Binding Cassette Transporters
  • Apolipoproteins E
  • Benzoates
  • Cholesterol, HDL
  • Cytokines
  • Inflammation Mediators
  • ethyl gallate
  • Gallic Acid