Disruption of giant unilamellar vesicles mimicking cell membranes induced by the pesticides glyphosate and picloram.

Affiliation

Faculdade de Ciências e Tecnologia (FCT)-Universidade Estadual Paulista (UNESP)-Presidente Prudente, SP 19060-900, Brazil. Electronic address: [Email]

Abstract

Giant unilamellar vesicles (GUVs) have been one of the most extensively investigated membrane model to study cell membrane-ligand interactions. In this study, we investigated the interaction between glyphosate and picloram with GUVs made with sphingomyelin (SM), cholesterol (CHOL), and dioleoyl-sn-glycerol-3-phosphocholine (DOPC) (DOPC/SM (1:1), DOPC/CHOL/SM (1:1:1)) in a physiological environment using confocal and phase contrast microscopy. At high pesticide concentrations (70 to 90 μM), we generally found the GUVs undergoing a physical such as contouring, elongation, and eventually lose their characteristic spherical shape. In addition, to determine the comparative effect of the pesticides, control experiments were performed using GUVs made with only DOPC and DOPC/SM 1:1. The results show that, at low concentration (0.5 μM), a significant effect was observed during a 30 min incubation time. These findings also suggest that cholesterol may play a significant role in the permeability of the vesicle against the action of the pesticides, which have important biological implications on the lipid composition of the membrane.

Keywords

Confocal microscopy,GUVs,Glyphosate, picloram,Lipids,Phase-contrast,