Current perspectives in cell-based approaches towards the definition of the antioxidant activity in food

Foods are natural sources of antioxidant compounds, that are known for their role in preventing many human diseases. Although several methods to assess the antioxidant activity/capacity of foods and their bioactive components have been developed, a simple universal method has not been proposed. Since both in vitro and in vivo assays have limitations, cell-based assays are gaining plenty of attention as a more suitable middle ground between in vitro chemical assays and in vivo studies. This review highlights the need for a transition to more biologically relevant cellular assays, and explores the latest developments and applications in the field. Lastly, critical insights, new emerging perspectives and future directions are presented. The most employed cell-based assay is the Cellular Antioxidant Activity (CAA). To date, Caco-2 cells represent the most suitable model to perform CAA as well as for bioavailability studies, which in turn plays a pivotal role in determining the biological activity of food antioxidants. In this review, the most recent applications of the Caco-2 cell line in the evaluation of both CAA and bioavailability are reported. Notwithstanding, CAA and cell cultures in general, also present critical aspects that cannot be under-appreciated. In order to overcome these limitations, new cell-based approaches are emerging and further efforts will be necessary in the coming years to obtain new, robust and reliable screening tools for an ever-better prediction of the antioxidant activity/capacity of foods in vivo. •In vitro and in vivo evaluation of food antioxidants have limitations.•Cellular Antioxidant Activity (CAA) assay provides biologically relevant results.•Caco-2 cell line is the most adequate model for CAA and bioavailability assays.•Standardization of CAA assay is still necessary.