In vitro antioxidant capacity and anti-inflammatory activity of seven common oats Yi-Fang Chu a,⇑ , Mitchell L. Wise b , Apeksha A. Gulvady a , Tony Chang c , David F. Kendra d , B. Jan-Willem van Klinken a , Yuhui Shi a , Marianne O’Shea a a PepsiCo R&D Nutrition, 617 W. Main Street, Barrington, IL 60010, USA b USDA-ARS Cereal Crops Research, 502 Walnut St., Madison, WI 53726, USA c International Chemistry Testing, 258 Main Street, Suite 311, Milford, MA 01757, USA d PepsiCo R&D Agronomy, 617 W. Main Street, Barrington, IL 60010, USA article info Article history: Received 13 September 2012 Received in revised form 6 December 2012 Accepted 25 January 2013 Available online 10 February 2013 Keywords: Oats Avenanthramides ORAC NF-jB Antioxidant Anti-inflammatory abstract Oats are gaining increasing scientific and public interest for their purported antioxidant-associated health benefits. Most reported studies focused on specific oat extracts or particular oat components, such as b- glucans, tocols (vitamin E), or avenanthramides. Studies on whole oats with respect to antioxidant and anti-inflammatory activities are still lacking. Here the antioxidant and anti-inflammatory activities from whole oat groats of seven common varieties were evaluated. All oat varieties had very similar oxygen rad- ical absorption capacity compared with other whole grains. In an anti-inflammatory assay, oat variety CDC Dancer inhibited tumor necrosis factor-a induced nuclear factor-kappa B activation by 27.5% at 2 mg/ml, whereas variety Deiter showed 13.7% inhibition at a comparable dose. Avenanthramide levels did not correlate with the observed antioxidant and anti-inflammatory activities. Further investigations are needed to pinpoint the specific antioxidant and anti-inflammatory compounds, and potential syner- gistic and/or matrix effects that may help explain the mechanisms of oat’s anti-inflammatory actions. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Oxidative stress and inflammation play critical roles in the pathogenesis of many diseases, such as cancer, cardiovascular dis- ease, arthritis, and obesity (de Heredia, Gomez-Martinez, & Marcos, 2012; Reuter, Gupta, Chaturvedi, & Aggarwal, 2010; Sesti, Tsitsilo- nis, Kotsinas, & Trougakos, 2012). Oxidative stress occurs when the balance between pro-oxidants and antioxidants is disturbed, resulting in a relative increase in pro-oxidant compounds. This imbalance can ultimately damage macromolecules, including pro- teins, lipids, carbohydrates, and DNA (Ames & Gold, 1991). The most common harmful reactive oxygen species (ROS) existing in the body are peroxyl radicals. Inflammatory pathways contribute to and are regulated by oxidative stress. Nuclear factor-kappa B (NF-jB) is a family of eukaryotic nuclear transcription factors that regulate the transcription of DNA and are involved in the activation of genes related to inflammatory and im- mune responses. The regulation of the inflammatory response by NF-jB occurs via the enhancement of the expression of genes encoding proinflammatory cytokines, such as tumor necrosis factor (TNF)-a, interleukin (IL)-6, and IL-1b. Activation of NF-jB leads to inflammation that in turn is involved in the pathogenesis of many diseases, such as asthma, rheumatoid arthritis, and inflammatory bowel disease (Tak & Firestein, 2001), and is at least partially responsible for diseases such as atherosclerosis and Alzheimer’s disease (Collins & Cybulsky, 2001; Mattson & Camandola, 2001). Mutations in the NF-jB pathway are also common in human can- cers (Rayet & Gelinas, 1999). In addition to anti-inflammatory drugs and immunosuppressive agents, naturally occurring phenolic compounds from plants such as flavonoids, quercetin, and resveratrol have also been shown to suppress inflammation and promote health (Holmes-McNary & Baldwin, 2000; Tsai, Lin-Shiau, & Lin, 1999). Epidemiologic studies have demonstrated an inverse relationship between the intake of whole grains and chronic disease (O’Neil, Nicklas, Zanovec, & Cho, 2010). In addition to vitamins and minerals present in grains, unique phytochemicals such as derivatives of benzoic and cin- namic acids and amino phenolic compounds may contribute to this protective effect. Many grain phytochemicals have antioxidant capacity and may help protect cells against oxidative damage (Okarter & Liu, 2010). Since relatively little attention has been paid to grain phytochemicals compared to fruits and vegetables, further studies are needed to characterise these effects. Oats have received increasing scientific and public interest for their antioxidant-associated health benefits (Peterson, 2001). The most well-known compounds with antioxidant capacity are toc- opherols, tocotrienols, and the derivatives of benzoic and cinnamic acids and aldehydes. Recently, a group of amides unique to oats, named avenanthramides, has been found. There are likely more 0308-8146/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.foodchem.2013.01.104 ⇑ Corresponding author. Tel.: +1 847 304 2006; fax: +1 847 304 2029. E-mail address: yifang.chu@pepsico.com (Y.-F. Chu). Food Chemistry 139 (2013) 426–431 Contents lists available at SciVerse ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem