Interaction of β-caryophyllene and β-caryophyllene oxide with phospholipid bilayers: differential scanning calorimetry study

The ability of the flavouring sesquiterpenes β-caryophyllene and β-caryophyllene oxide to be absorbed into the cell has been investigated by an in vitro biomembrane model of multilamellar vesicles. Dimyristoylphosphatidylcholine was used as a constituent of the biomembrane and permitted the experiments to be carried out at 37.0 °C, close to body temperature. Differential scanning calorimetry was applied for measuring the effect of the compounds on the thermotropic behaviour of the vesicles. Studies were also carried out in order to characterize the interference of an aqueous medium or a lipid carrier with the uptake of the substances by the biomembrane. The results showed that both sesquiterpenes influenced the behaviour of the multilamellar vesicles, with β-caryophyllene producing a larger effect than β-caryophyllene oxide. The aqueous medium hindered the absorption of the test substances, probably because of their low water solubility; on the contrary, the lipophilic medium strongly favoured their uptake. Present results provide preliminary information on the bioavailability of β-caryophyllene and β-caryophyllene oxide and allow us to expect their uptake through cell membranes. Moreover, these results could be of importance for future design of lipophilic delivery systems for these sesquiterpenes.