title: Preparation and characterization of liposomes incorporating cucurbitacin E, a natural cytotoxic triterpene.
abstract: Cucurbitacin E (Cuc E), highly oxygenated triterpene from cucurbitaceae family, was demonstrated to possess anti-proliferative, anti-inflammatory and anti-oxidant activities. Here, we studied the effect of Cuc E on the properties of the phospholipid membrane. Large unilamellar vesicles, with and without sulforhodamine B (SRB), were prepared in the absence and presence of Cuc E. The fluorescence increase, resulting from SRB release from vesicles due to inhibition of auto-quenching, was used to assess the permeability of liposome at 4° and 37°C. At 4°C, blank liposomes and those containing Cuc E were stable; while at 37°C Cuc E loaded liposomes showed less stability than blank ones. The loading efficiency of Cuc E into the vesicles was demonstrated to be 85% by HPLC. Dynamic light scattering measurements showed that liposomes embedding Cuc E were smaller than those which did not. Multilamellar vesicles were manufactured from dipalmitoylphosphatidylcholine in the presence and absence of Cuc E (molar ratio 7%). Results obtained by differential scanning calorimetry suggest that Cuc E binds mainly at the polar/apolar interfacial region of lipid bilayers and may incorporate into the lipid bilayer. Cuc E does not produce phase separation and thus might be included in liposome formulation.
authors.affiliation: Bioactive Molecules Research Group, PRASE, Doctoral School of Sciences and Technologies, Lebanese University, Lebanon.
authors.forename: Lamice
authors.initials: L
authors.lastname: Habib
authors.forename: Nathalie
authors.initials: N
authors.lastname: Khreich
authors.forename: Alia
authors.initials: A
authors.lastname: Jraij
authors.forename: Suzanne
authors.initials: S
authors.lastname: Abbas
authors.forename: Jacques
authors.initials: J
authors.lastname: Magdalou
authors.forename: Catherine
authors.initials: C
authors.lastname: Charcosset
authors.forename: Hélène
authors.initials: H
authors.lastname: Greige-Gerges
mesh_terms: D002152:Calorimetry, Differential Scanning; D003603:Cytotoxins / Q000008:administration & dosage*; D004339:Drug Compounding; D005456:Fluorescent Dyes / Q000378:metabolism; D008051:Lipid Bilayers / Q000378:metabolism*; D008081:Liposomes; D010743:Phospholipids / Q000378:metabolism; D012235:Rhodamines / Q000378:metabolism; D014315:Triterpenes / Q000008:administration & dosage*
chemical_list: D003603:Cytotoxins; D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D008081:Liposomes; D010743:Phospholipids; D012235:Rhodamines; D014315:Triterpenes; C022027:lissamine rhodamine B; C102326:cucurbitacin E