MYRSINOIC ACID INTERACTION IN CELL MEMBRANE MODELS USING LANGMUIR MONOLAYERS

Natural compounds from plants, such as mirsinoic acid, employed in this work, have the potential to serve as a basic structure in the development of drugs. Particularly, mirsinoic acid presents antitumor and anti-inflammatory activity. Many of these activities involve interaction with lipid surfaces, including cell membranes, which can be modeled using Langmuir films. This monomolecular structure is formed by insoluble amphiphiles at the air-water interface when spread from their organic solvents. The present work aims to study the interaction of mirsinoic acid with simple models of membranes composed of the zwitterionic phospholipid, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), widely found in biological membranes, responsible for reducing surface tension in the lungs during breathing, also known to mimic erythrocyte membranes. For the analysis of the effects of the drug on the lipid, both were co-spread on the air-water interface and characterized using tensiometric, morphological (Brewster Angle Microscopy-BAM), electrical (intensity potential) surface) and rheological (oscillating barriers) techniques. The surface pressure isotherms -molecular area revealed that the acid condensed the DPPC monolayer, with visible changes in the morphology of the films with the formation of interfacial aggregates, in addition to stabilizing the previously compressed monolayers up to 30 mN/m and decreasing the surface potential. Considering the compression-decompression curves, they presented hysteresis for the monolayer with the compound. In turn, the rheological measurements showed that the acid decreases the viscoelastic modulus for the DPPC monolayer, making the film more fluid. The results presented above make it possible to determine the possible biological implications of its effects on cell membrane models, given that we could detect the drug's interaction with the Langmuir monolayers.
This work was supported by FAPESP (2023/07185-8, 2022/03736-9) and CNPq.