Antioxidant activity and protective effects of peptide lunasin against oxidative stress in intestinal Caco-2 cells

Oxidative stress is one of the most critical factors implicated in many disorders of the gastrointestinal tract, such as inflammatory bowel diseases and colon cancer. Lunasin is a seed peptide known by its properties against cancer and cardiovascular diseases. The present study investigated the in vitro antioxidant activity of this peptide that demonstrated to be a potent scavenger of peroxyl and superoxide radicals. In addition, the protective role of lunasin on cell viability and antioxidant defenses of human Caco-2 cells challenged by hydrogen peroxide and tert-butylhydroperoxide was evaluated. This peptide remained partially intact during incubation time with cells, preventing of the oxidative damage induced by both chemical agents. The direct antioxidant action of lunasin (within the physiological range of concentrations) on enterocytes exposed to oxidizing species makes this peptide a promising agent to preserve the integrity of intestinal mucosa against oxidative damage related diseases. © 2013 Elsevier Ltd.This work has received financial support from projects AGL2011-24643, Consolider Ingenio 2010 FUN-C-Food CSD2007-00063, P2009/AGR-1469, FEDER-INNTERCONECTA-GALICIA (ENVELLEFUN) and FP7-SME-2012-315349 (FOFIND). The authors are participant in the FA1005COST Action INFOGEST on food digestion. B.H.-L. acknowledges Ministry of Economy and Competitiveness for her “Ramón y Cajal” contract.Peer Reviewe