Loading and release of phenolic compounds from mexican oregano ( Lippia graveolens) ) in different Cationic-PEGylated matrixes and their effect on CACO-2 and CCD-18co cells

Phenolic compounds (PPHs) extracted from Mexican oregano ( Lippia graveolens) ) have shown various biological activities, including antioxidant, anti-inflammatory and anticancer properties. However, these compounds tend to be unstable, show low aqueous solubility, and are sensitive to changes in the pH and temperature of the medium. In this article, the encapsulation of this type of phenolic compounds in different poly(ethylene glycol) (PEG) functionalized cationic matrixes, based on poly(N,N '-diethylaminoethyl N,N '-diethylaminoethyl methacrylate) (PDEAEM) and Chitosan (CS), is reported. Particle sizes between 122 and 458 nm were obtained for the PDEAEM and CS platforms, and the loading content was around 62 % for both systems, while the loading efficiency was higher than 90 %. The identification of the loaded phenolic compounds by Ultra High-Resolution Liquid Chromatography/Mass Spectrometry (UPLC/MS) predominantly showed hesperidin, naringenin, phloridzin, and cirsimaritin. As compared with the plant extract, the prepared formulation led to an increase in the extract's stability and antioxidant activity. It was also observed that concentrations of loaded extract <= 500 mu g mL-1-1 did not show cytotoxicity in CCD18 fibroblasts, while they exhibited substantial antiproliferative activity in colon cancer cells (CACO-2). After 72 h, the activity of the loaded systems was similar to the anticancer drug 5-fluorouracil, so these cationic systems loaded with phenolic compounds could act as a good coadjutant in the treatment of colon cancer.