*3.1. Membrane Stability*

Many studies have shown that resveratrol interacts with membrane lipids due to its lipophilicity. Resveratrol's localization in membranes or membrane models is a matter of debate.

In this study, we used a classic electrophysiological method to investigate resveratrol's microscopic incorporation at concentrations of 10 and 20 µM, in PLMs of different composition. Channel-like event formation indicates that molecules of a substance are incorporating into the membrane. PLMs of different composition were used to see whether resveratrol is able to incorporate into PLMs and to form conductive units, and under what experimental conditions. With this aim, POPC was used as a zwitterionic membrane, POPC:Ch as a neutral mixed membrane and DOPS:DOPE as a mixed membrane with diluted charges.

First of all, we tested PLM stability by applying a voltage of ±120 mV for 10–15 min under stirring and by monitoring the constant values for PLM conductance and capacitance. Preliminarily, to exclude any non-specific and destabilizing effects of DMSO per se on the PLMs used, we performed experiments by adding 4 or 8 µL of a H2O:DMSO (6:1) mixture to the medium, on the *cis* side of the membrane. In many different experiments and independently of lipid composition, the PLMs were stable even when applying a voltage of ±100 mV for 12 h under stirring and monitoring the constant values for PLM conductance and capacitance.
