Avenanthramide

Avenanthramide

Avenanthramides are a type of oat phytoalexins that exist predominantly in the groats of oat seeds.

Among a group of at least 25 avenanthramides that differ in the substituents on the cinnamic acid and anthranilic acid rings, three are predominant in oat grain: Bc (also called avenanthramide C), Bf (also called avenanthramide B) and Bp (also called avenanthramide A).

In vitro experiments indicate they have significant antioxidant activities, with Bc > Bf > Bp. In human and animal tests, this antioxidant capacity provides health benefits ranging from reduced rate of LDL oxidation to protecting against cancers and heart disease. Because of its antioxidant properties, high levels of avenanthramide are desirable in oat grain. Researchers at the Agricultural Research Service (ARS) currently are trying to understand what environmental factors regulate the amount of avenanthramide produced in oat grain. Past studies have found an increase in avenanthramide production in plants that are infected by a fungus, leading researchers to believe that avenanthramide is used as a chemical defense in helping the oat grain fight off the fungus. ARS researchers found that cultivars with the strongest resistance to crown rust, a fungus that affects oat grains, had the highest concentration of avenanthramide. However, because not all cultivars with high crown rust resistance had high levels of avenanthramide, researchers suspect other environmental factors play a role in avenanthramide production. Nevertheless, scientists suggest farmers can still select for highly resistant cultivars to increase the production of avenanthramide in their grain.

They are tranilast analogues and have anti-inflammatory and antifibrotic properties, probably due to TGF-beta inhibitory effects.