Effects of avenanthramides on oxidant generation and antioxidant enzyme activity in exercised rats

Avenanthramides (AVEN) are major phenolic acids in oat (Avena sativa L.) that have potent antioxidant functions. Female Sprague-Dawley rats (n = 48, age 6-7 wk) were fed either an AIN-93 based control (C) diet or the same diet containing 0.1 g/kg AVEN-Bc [N-(3′,4′ -dihydroxycinnamoyl)-5-hydroxyanthranilic acid] for 50 days. Each group was further divided into rested (R) and exercised (E, treadmill running at 22.5 m/min, 10% grade for 1 hour) prior to killing. AVEN supplementation per se had no effect on reactive oxygen species (ROS) production in most tissues, except soleus muscle wherein ROS level was decreased. AVEN-fed rats had higher superoxide dismutase (SOD) activity in the deep portion of vastus lateralis muscle (DVL), liver and kidney and higher glutathione peroxidase (GPX) activity in the heart and DVL, compared to C-fed rats. E increased ROS production in the liver, DVL and soleus, and lipid peroxidation in the heart, liver and DVL. AVEN attenuated E-induced ROS in soleus and lipid peroxidation in the heart, but enhanced lipid peroxidation in DVL. We conclude that AVEN can serve as a potential dietary antioxidant supplement, but its tissue specific effects require further investigation.