Institute of Chemical Biology, National Hellenic Research Foundation, 48, Vassileos Constantinou Ave., 11635, Athens, Greece; Laboratory of Biotechnology, Department of Biological Applications and Technologies, University of Ioannina, 45110, Ioannina, Greece.
Laboratoire Chimie et Biologie des Membranes et des Nanoobjets, Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR 5248, Pessac, France.
Colloids Surf B Biointerfaces. 2019 Dec 1;184:110482. doi: 10.1016/j.colsurfb.2019.110482. Epub 2019 Sep 7.
Over the last years, the incorporation of natural antioxidants in food and pharmaceutical formulations has gained attention, delaying or preventing oxidation phenomena in the final products. In order to take full advantage of their properties, protection in special microenvironments is of great importance. The unique features of the natural phenolic compound hydroxytyrosol (HT) - including antioxidant, anti-inflammatory, antiproliferative and cardioprotective properties - have been studied to clarify its mechanism of action. In the present study novel biocompatible water-in-oil (W/O) microemulsions were developed as hosts for HT and subsequently examined for their absorption profile following their oral uptake. The absorption of HT in solution was compared with the encapsulated one in vitro, using a coculture model (Caco-2/TC7 and HT29-MTX cell lines). The systems were structurally characterized by means of Dynamic Light Scattering (DLS) and Electron Paramagnetic Resonance (EPR) techniques. The diameter of the micelles remained unaltered after the incorporation of 678 ppm of HT but the interfacial properties were slightly affected, indicating the involvement of the HT molecules in the surfactant monolayer. EPR was used towards a lipophilic stable free radial, namely galvinoxyl, indicating a high scavenging activity of the systems and encapsulated HT. Finally, after the biocompatibility study of the microemulsions the intestinal absorption of the encapsulated HT was compared with its aqueous solution in vitro. The higher the surfactants' concentration in the system the lower the HT concentration that penetrated the constructed epithelium, indicating the involvement of the amphiphiles in the antioxidant's absorption and its entrapment in the mucus layer.
在过去的几年中，将天然抗氧化剂纳入食品和药物制剂中引起了人们的关注，以延迟或防止最终产品中的氧化现象。为了充分利用它们的特性，在特殊的微环境中进行保护非常重要。天然酚类化合物羟基酪醇（HT）的独特特性 - 包括抗氧化，抗炎，抗增殖和心脏保护特性 - 已经过研究，以阐明其作用机制。在本研究中，开发了新型的生物相容性水包油（W / O）微乳液作为 HT 的宿主，随后检查了其口服摄取后的吸收情况。通过共培养模型（Caco-2 / TC7 和 HT29-MTX 细胞系），将 HT 在溶液中的吸收与包封后的吸收进行了体外比较。通过动态光散射（DLS）和电子顺磁共振（EPR）技术对系统进行了结构表征。在掺入 678ppm HT 后，胶束的直径保持不变，但界面特性略有变化，表明 HT 分子参与了表面活性剂单层。EPR 用于疏水性稳定的自由基，即戊二醛，表明系统和包封的 HT 具有很高的清除活性。最后，在对微乳液进行生物相容性研究后，将包封的 HT 的肠内吸收与其在体外的水溶液进行了比较。体系中表面活性剂浓度越高，穿透构建的上皮的 HT 浓度越低，表明两亲物参与了抗氧化剂的吸收及其在粘液层中的包裹。
