PP57 - Examination of the Antioxidant capacity of water extracts of common teas using the Cellular Antioxidant Activity (CAA) assay

Abstract

Oxidative stress leads to a high production of free radicals, which are related with more than a hundred of human diseases, including cancer, atherosclerosis and Alzheimer’s, and may be important in the process of ageing. Natural products rich in antioxidant compounds can neutralize in vitro the potentially harmful free radicals, suggesting that an antioxidants-rich diet might provide health benefits. Several in vitro methods have been developed to test the antioxidant potential of foods. Though, these assays do not evaluate the antioxidants in a physiological environment and do not take consideration of the complexity of a biological system. The goal of this study was to investigate the antioxidant activity of water extracts of commercial teas within a cellular model. The antioxidant activity was determined using the peroxyl radical scavenging capacity (PSC) and the oxygen radical absorbance capacity (ORAC) methods and compared with the in vivo results obtained with the cellular antioxidant activity (CAA) assay. The results of this study showed that despite some extracts have a relative high ranking of antioxidant potential, this rank is dependent on the chemical method used. Furthermore, the chemical results are weakly correlated with the cell-based method. Considering the fact that antioxidants are effective in preventing various chronic diseases, the potential antioxidant role of dietary antioxidants within a cellular model certainly merits further attention. The CAA assay takes into account some key biological parameters that have to be considered to estimate the in vivo potential result.