Salt effects on mixed composition membranes containing an antioxidant lipophilic edaravone derivative: a computational-experimental study

Org Biomol Chem. 2022 Jul 27;20(29):5784-5795. doi: 10.1039/d2ob01143c.

Abstract

The protection of lipid membranes against oxidation avoids diseases associated with oxidative stress. As a strategy to contrast it, functionalized lipids with antioxidant activity are used to become part of membranes thus protecting them. For this purpose, a lipophilic edaravone derivative has been synthesized, adding a C18 saturated chain to the original structure. The antioxidant activity of C18-Edv has been demonstrated in our previous work. In this study, molecular dynamics simulations have been performed to define the effects of NaCl, MgCl2, KCl, and CaCl2 salts on a palmitoyl-oleoyl-sn-glycero-phosphocholine (POPC) lipid bilayer encapsulating C18-Edv. The results showed how different salts influence POPC lateral diffusion, and the movements of C18-Edv heads, which are antioxidant moieties, were correlated to the ability of C18-Edv molecules to protect membranes. MgCl2 showed a negative impact leading to C18-Edv clusterization and membrane stretching, while KCl and NaCl showed a moderate influence on the mixed lipid membrane structure. CaCl2 increased the exposure of the C18-Edv heads to the lipid-water interface, resulting in the salt with a higher propensity to guarantee protection against radicals in the aqueous phase. Finally, C18-Edv-POPC liposomes have been prepared following the simulation conditions, and then an experimental Oxygen Radical Absorbance Capacity (ORAC) assay has been performed to confirm the in silico predicted results.

MeSH terms

  • Antioxidants* / pharmacology
  • Calcium Chloride
  • Edaravone
  • Lipid Bilayers / chemistry
  • Molecular Dynamics Simulation
  • Phosphatidylcholines* / chemistry
  • Salts
  • Sodium Chloride
  • Water / chemistry

Substances

  • Antioxidants
  • Lipid Bilayers
  • Phosphatidylcholines
  • Salts
  • Water
  • Sodium Chloride
  • Calcium Chloride
  • Edaravone