Synergistic activity between a spinach-derived natural antioxidant (NAO) and commercial antioxidants in a variety of oxidation systems

Recently, there has been great interest in the potential health benefits of foods containing polyphenols, especially from plants, due to their antioxidant content. Natural antioxidant (NAO) is a unique, powerful antioxidant which was isolated in our lab from spinach leaves. The main goal of this study was to examine potential synergistic activity in combinations of NAO and commercial antioxidants. The antioxidant activity was tested in several in vitro systems including fatty acid and fat oxidation and also in cancer cell lines. We used the unique optical live cell array (LCA) technology to monitor the generation of reactive oxygen species (ROS) in single cells over time. NAO was combined with selected commercial antioxidants, and synergistic activity that reduced ROS generation was found with three polyphenols – ferulic acid, caffeic acid, and epigallocatechin-3-gallate (EGCG). These findings demonstrate the importance of using antioxidant ‘cocktails’ which may enhance medical effects in many kinds of diseases, including cardiovascular diseases and cancer.