Calorimetric evaluation of the interaction and absorption of eicosapentaenoic acid by biomembrane models

The interaction of eicosapentaenoic acid, a polyunsaturated fatty acid belonging to the omega-3 class, with biomembrane models represented by multilamellar or unilamellar vesicles made of dimyristoylphosphatidylcholine was monitored by means of differential scanning calorimetry technique. The calorimetric analysis of vesicle prepared in the presence of increasing molar fraction of eicosapentaenoic acid was carried out to show its maximum interaction with biomembrane models evaluating the effects of eicosapentaenoic acid on the biomembrane models thermotropic parameters (transition temperature and enthalpy variation). Furthermore, in order to detect the influence of the presence of hydrophilic or lipophilic media on the entity of the compound absorption by the biomembrane models, kinetic experiments were carried out. The results indicate that eicosapentaenoic acid strongly interacts with the biomembrane models depressing the transition temperature and the enthalpy variation. Eicosapentaenoic acid is absorbed by the biomembrane models and the absorption is affected by the used medium; in fact a bigger absorption happens in the presence of a lipophilic medium.