Phenolic amides (avenanthramides) in oats – a review

Abstract

Whole grain cereals such as oats are important sources of phenolic compounds. Oats contain phenolic amides, also named avenanthramides (AVAs), which have beneficial health properties because of their antioxidant, anti-inflammatory, and antiproliferative effects. The most common avenanthramides are esters of 5-hydroxyanthranilic acid with p-coumaric (AVA-A), ferulic (AVA-B), or caffeic (AVA-C) acids. The studies related to the stability of AVAs showed that AVA-B is sensitive to alkaline and neutral conditions and this sensitivity increases with higher temperatures. However, has been reported that AVA-A and AVA -C are more stable under the same conditions (alkaline and neutral conditions), and in addition that AVAs content of oats is increasing significantly with the germination process. AVAs help in preventing free radicals from damaging LDL cholesterol while AVAs-enriched extract of oats combined with vitamin C synergistically inhibited LDL oxidation in vitro. Both animal studies and human clinical trials confirmed that oats antioxidants have the potential of reducing cardiovascular risks by lowering serum cholesterol and inhibiting LDL oxidation and peroxidation. Therefore, the consumption of oats and products thereof is extremely important in reducing the risk of cardiovascular diseases.