Synthesis, characterization and cytotoxicity of the Eugenia brejoensis essential oil inclusion complex with β-cyclodextrin

This study investigated for the first time the effect of Eugenia brejoensis essential oil (EB) and its inclusion complex (IC) with beta-cyclodextrin (beta-CD) on Hela and J774 cell lines. Solid IC was prepared by the coprecipitation method and characterized by several analytical methods: differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), X-ray diffraction (XRD), RAMAN spectroscopy and scanning electron microscopy (SEM). The loading capacity (LC) was determined. The formation constant of beta-CD/caryophyllene (the main constituent of EB essential oil) as well as the ability of beta-CD to retain EB and caryophyllene were evaluated by static headspace gas chromatography (SH-GC) in aqueous solution. Finally, the cytotoxicity of EB and beta-CD/EB IC was determined on Hela and J774 cell lines. We clearly demonstrated the formation of an inclusion complex between EB EO and beta-CD in solid state and aqueous solution. Indeed, the amount of EB included in the solid IC was equal to 4.7 mu g of essential oil/mg of solid complex and the obtained formation constant between beta-CD and beta-(E)-caryophyllene, the main constituent of the EB, was as high as 28460 M-1. Moreover we could observe a greater selectivity of the beta-CD/EB IC for the tumor lineage. Therefore, beta-CD/EB IC could be a promising agent with potential application in anticancer drug development.