P5: Potential of Bile Salt-Containing Liposomes as Carriers of Health-Promoting Resveratrol

Aygul Can, Olivia Pabois, James Doutch, Arwen I I Tyler, and Alan R Mackie

School of Food Science and Nutrition, University of Leeds, UK

Resveratrol, a well-known phenolic compound, displays health-promoting functions such as anti-oxidant, anti-microbial, and anti-inflammatory activities. However, its therapeutic efficacy is restricted by its low solubility in aqueous media and consequently, in biological fluids. Its bioavailability has been reported to be lower than 1% because of first-pass metabolism and rapid clearance from the circulation, as well as interaction with enzymes, bile salts (BS), and mucosal barriers in the gastrointestinal tract [1].

One proposed solution towards optimising the bioavailability and health benefits of resveratrol consists of encapsulating the bioactive into negatively charged BS-containing liposomes. Through electrostatic repulsion, these BS/lipid vesicles are thought to stabilize the bilayer against intestinal BS adsorption and subsequent digestion, ultimately leading to a slower vesicle-to-mixed micelle transition and enhanced delivery of resveratrol [2].

In this study, resveratrol (0.100 and 0.133 mM) was incorporated in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC, 10 mM) vesicles containing different concentrations of sodium cholate (5.0, 7.5 and 10 mM). The structure of formulations was characterised by combining light scattering with small-angle neutron scattering (SANS). Stability was investigated at both 4°C and 20°C, by monitoring the time-dependent evolution of their size, polydispersity, and charge density.

SANS studies revealed that pure lipid extruded liposomes were mostly unilamellar, with a small subpopulation of bi- and tri-lamellar vesicles. Upon incorporation of BS, different colloidal structures appeared, ranging from pure unilamellar spherical vesicles to ellipsoidal vesicles coexisting with spherical vesicles in a concentration-dependent manner. During storage, resveratrol-incorporating BS/lipid vesicles were found to remain stable, displaying an average diameter of ~180 nm with a relatively low polydispersity (PDI<0.250). BS-containing liposomes exhibit high potential as novel carriers of bioactives. While BS-containing liposomes are already utilized in pharmaceutics, they have yet to be employed for the encapsulation of bioactives in the food industry. Our data suggest that they can be adapted to the requirements for food formulations.

Keywords: bile salt-containing liposomes, resveratrol bioavailability, small-angle neutron scattering

[1]        Walle, T., Ann. N. Y. Acad. Sci., 2011, 1215(1), 9-15

[2]        Elnaggar, Y.S., Omran, S., Hazzah, H.A., & Abdallah, O.Y., Int. J. Pharm., 2019, 564, 410-425.

Key dates

Registration deadline:

31 January 2022

Organised by the IOP Food Physics Group