Cellular antioxidant effect of bioactive peptides and molecular mechanisms underlying: beyond chemical properties

Summary Bioactive peptides are known for their chemical antioxidant activities. However, the importance of cellular antioxidant peptides has relatively been overlooked; nevertheless, scientific evidence supporting their potential to prevent chronic diseases associated with oxidative stress is progressively increasing. Cellular in vitro and in vivo studies have demonstrated that antioxidant bioactive peptides possess cellular antioxidant activity, decrease oxidative stress biomarkers (e.g. lipid peroxidation, intracellular ROS levels, apoptosis), increase diverse antioxidant enzymes’ activities and modulate levels of antioxidant molecules. These cellular in vitro bioactive properties and in vivo health effects suggest that antioxidant peptides could be used as components of functional foods and contribute to health promotion by improving specific physiological functions. This review highlights the scientific evidence about cellular antioxidant activity of bioactive peptides, their protective effect and underlying molecular mechanisms of action. It also describes the underlying antioxidant mechanisms and the structure–function relationship of antioxidant peptides.