Abstract

CORNEJO MEJIA, Cesar Mauricio et al. An experimental study of the physical properties of saponins and their interaction with gram negative bacterial membrane models using Langmuir-Blodgett techniques and atomic forcé microscopy. Revista Boliviana de Física [online]. 2023, vol.42, n.42, pp.12-21. ISSN 1562-3823.

Abstract Saponins are non-ionic biosurfactants that exhibit antifungal, antiviral and antibacterial properties. However, the mechanisms by which saponins exhibits these properties are not well understood. In the present work, Langmuir and atomic forcé microscopy (AFM) tech-niques were employed to investígate the interactions of saponins with a model of Gram-negative bacterial membranes. The lipid films contained extracts of phosphatidylethanola-mine and phosphatidylglycerol from Escherichia coli bacteria. The results suggest that saponins repel phospholipids, thereby increasing membrane fluidity. They also showed evidence of adsorption of the saponin by the membrane model. These results were cross-checked with AFM images. A mechanism for how saponin alters the phospholipid membrane is proposed. Langmuir technique and atomic forcé microscopy proved to be useful tools to investígate the interaction of biologically relevant compounds with cell membrane models. The results of the surface pressure measurements, combined with those obtained from AFM, provided evidence for the susceptibility of membranes to the insertion of saponins and their possible modes of action. The results of this study may contribute to a better understanding of the mechanisms of antifungal, antiviral and antibacterial activity of saponins

Keywords : Langmuir; Blodgett monolayers; saponins; phospholipids; atomic forcé microscopy.

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