Thermotropic phase behaviour of α-dipalmitoylphosphatidylcholine multibilayers is influenced to various extents by carotenoids containing different structural features- evidence from differential scanning calorimetry

Abstract

Carotenoids are the effective modulators of physical properties of model and natural membranes. To demonstrate the relationship between the structure of carotenoids and their effect on the molecular dynamics of membranes, we have investigated the influence of five structurally different carotenoids: beta-carotene, lycopene, lutein, violaxanthin, zeaxanthin and additionally carotane--a fully saturated derivative of beta-carotene, on thermotropic phase behaviour of dipalmitoylphosphatidylcholine (DPPC) multilamellar vesicles by means of differential scanning calorimetry (DSC). The results obtained indicate that the carotenoids used modulated the thermotropic properties of multibilayers to various extents, broadening the pretransition and the main phase transition peaks and shifting them to lower temperatures. Pronounced decrease of pretransition enthalpy (DeltaH(p)) proves that carotenoids very strongly alter the membrane properties in its gel phase. Comparison of the influence of several carotenoids shows that a rigid, polyisoprenoid chain plays a basic role in altering the thermotropic properties of such membranes and the presence of rings without oxygen-containing groups has a minor significance for the observed interactions. Carotenoids containing epoxy and/or hydroxy groups attached to their rings modify the thermotropic phase behaviour of DPPC multilamellar vesicles stronger than carotenes--a result of their orientation in the DPPC bilayer.

Interactions between canthaxanthin and lipid membranes — possible mechanisms of canthaxanthin toxicity

“…For DPPC and DSPC, the effect was much weaker, but a distinct change in the enthalpy was observed at pigment concentrations between 0.1 and 0.2 mol%. The observed disappearance of the pre-transition peak of DMPC (and DPPC) indicated fluidisation of the L β' phase, as reported previously for other xanthophylls [68,70]. The lack of ester carbonyl groups in DHPC resulted in a narrowing of the pretransition component, especially for canthaxanthin concentrations as low as 0.05 mol%, which suggested an ordering effect of canthaxanthin.…”

“…The effects from polar carotenoids were found to be much greater than those from non-polar pigments [37,68,69]. The effect of canthaxanthin on the thermotropic properties of lipid membranes formed with different lipids was discussed in detail in [57].…”

Hyaluronic acid-coated liposomes for active targeting of gemcitabine

“…This indicates a strong insertion of C12GEM within the DPPC membrane due to strong hydrophobic interactions as observed for other drugs [34][35][36][37][38]. This phenomenon persisted in the presence of conjugated HA of both molecular weights.…”

Characterisation of Carotenoids Involved in the Xanthophyll Cycle

“…In general, polar carotenoids were capable of influencing the thermotropic phase behaviour of phospholipid membranes. As a result, main phase transition (P β′ →L α ) was shifted to lower temperature in a concentration dependent manner accompanying by a decreased cooperativity and the molar heat capacity of the P β′ →L α transition [46]. Lutein and zeaxanthin affected alkyl chains of lipid bilayers by restriction of molecular motions of both CH 2 and the terminal CH 3 groups [47,48].…”