In vitro total antioxidant capacity and anti-inflammatory activity of three common oat-derived avenanthramides

To better understand mechanisms underlying the health benefits of oats, the free radical scavenging capacities of oat avenanthramides 2c, 2f, and 2p and their ability to inhibit NF-κB activation were evaluated. The antioxidant capacities of 2c, 2f, and 2p against peroxyl radicals, hydroxyl radicals, superoxide anion, singlet oxygen, and peroxynitrite were determined by using ORAC, HORAC, SORAC, SOAC, and NORAC assays, respectively. The total antioxidant capacity of 2c was approximately 1.5-fold those of 2f and 2p. Total antioxidant capacity was primarily attributable to SORAC and ORAC for 2c (>77%, p < 0.05), and to ORAC and SOAC for 2f. ORAC accounted for approximately 32% of total antioxidant capacity in 2p. EC50 values for inhibiting TNF-α-induced NF-κB activation in C2C12 cells were 64.3, 29.3, and 9.10 μM for 2c, 2f, and 2p, respectively. Differences in antioxidant capacities and ability to inhibit NF-κB among the avenanthramides could be ascribed to structural variations.