β-cyclodextrins influence on E-3,5,4’-trimethoxystilbene absorption across biological membrane model: A differential scanning calorimetry evidence

E-3,5,4-trimethoxystilbene (TMS) is a naturally occurring analog of resveratrol. The anti-neoplastic,antiallergic and anti-angiogenic activities of TMS have been recently reported. From the viewpoint ofmetabolism, TMS may be more favourable than resveratrol because all of its hydroxyl groups, which aresubjected to extensive glucuronide or sulphate conjugation in the metabolic pathways of resveratrol,are protected by methylation. Moreover, methylation increases lipophilicity and may enhance cell membranepermeability, but it decreases its solubility in aqueous media. A way to increase TMS solubilitycan be represented by complexation with -cyclodextrins. In the present paper, the differential scanningcalorimetry technique has been used to study the interaction of TMS with a biomembrane model constitutedby dimyristoylphosphatidylcholine multilamellar vesicles. Furthermore, kinetic experiments havebeen carried out to follow the uptake of TMS by biomembranes in the presence of -cyclodextrins to gaininformation on the effect of -cyclodextrins on the uptake process. Our results indicate that opportuneconcentrations of beta-cyclodextrins greatly improve the uptake of TMS by biomembrane models.