Effect of Erythrodiol, A Natural Pentacyclic Triterpene from Olive Oil, on the Lipid Membrane Properties

J Membr Biol. 2015 Dec;248(6):1079-87. doi: 10.1007/s00232-015-9821-x. Epub 2015 Jul 4.

Abstract

The effect of erythrodiol, a natural pentacyclic triterpene to which humans are exposed through nutrients, on the lipid membranes is studied using liposomes as a membrane model. Empty and erythrodiol-loaded liposomes were prepared by the reverse phase evaporation method followed by the extrusion and by the thin film hydration method. Liposomes were characterized in terms of size and zeta potential and were imaged by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The effect of erythrodiol on thermotropic behavior of DPPC bilayers is also examined by differential scanning calorimetry (DSC). The DSC thermograms suggested that erythrodiol interacted with the polar head groups of phospholipids and may produce a disruption of the ordering of the alkyl chains. The diffraction light scattering analysis showed that erythrodiol-loaded liposomes presented a decrease in the vesicle size when compared to blank liposomes. Images obtained by TEM confirmed the formation of unilamellar and spherical liposomes. AFM images showed spherical vesicles and single lipid bilayers. The latter were more abundant in the preparations containing erythrodiol than in the blank ones. Moreover, erythrodiol-loaded liposomes tended to rupture into single lipid bilayers during scanning. The study may provide a better understanding of pentacyclic triterpenes-membrane interaction.

Keywords: Atomic force microscopy; Differential scanning calorimetry; Dynamic light scattering; Erythrodiol; Liposomes; Transmission electron microscopy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Hep G2 Cells
  • Humans
  • Lipid Bilayers / chemistry*
  • Liposomes / chemistry*
  • Liposomes / ultrastructure
  • Microscopy, Atomic Force
  • Microscopy, Electron, Transmission
  • Molecular Structure
  • Oleanolic Acid / analogs & derivatives*
  • Oleanolic Acid / chemistry
  • Oleanolic Acid / pharmacology
  • Olive Oil / chemistry*
  • Particle Size
  • Pentacyclic Triterpenes / chemistry*
  • Pentacyclic Triterpenes / pharmacology
  • Thermodynamics

Substances

  • Lipid Bilayers
  • Liposomes
  • Olive Oil
  • Pentacyclic Triterpenes
  • erythrodiol
  • Oleanolic Acid