Antioxidative Activity of Ferulic Acid
The antioxidant action mechanism of ferulic acid is complex, mainly based on the inhibition of the formation of reactive oxygen species (ROS) or nitrogen, but also the neutralization (“sweeping”) of free radicals. In addition, this acid is responsible for chelating protonated metal ions, such as Cu(II) or Fe(II). Ferulic acid is not only a free radical scavenger, but also an inhibitor of enzymes that catalyze free radical generation and an enhancer of scavenger enzyme activity. It is directly related to its chemical structure. Its antioxidating properties are primarily related to scavenging of free radicals, binding transition metals such as iron and copper, and lipid peroxidation prevention. The mechanism of antioxidative activity of ferulic acid is the ability to form stable phenoxyl radicals, by the reaction of the radical molecule with the molecule of antioxidant. This makes it difficult to initiate a complex reaction cascade leading to the generation of free radicals. This compound may also act as hydrogen donor, giving atoms directly to the radicals. This is particularly important for the protection of cell membrane lipid acids, from undesired autoxidation processes. As a secondary antioxidant, ferulic acids and their related compounds are able to bind transition metals such as iron and copper. This prevents the formation of toxic hydroxyl radicals, which lead to cell membrane peroxidation.
Free radicals may also be formed through natural human physiological processes, such as cell respiration process. These reactions are catalyzed by some enzymes, among others xanthine oxidase and cyclooxygenase-2. It is suggested that inhibition of this enzyme could prevent the changes caused by oxidative stress, including photophobia. Literature data report high efficacy of ferulic acid and its derivatives in reducing xanthine oxidase and cyclooxygenase activity. It is therefore believed that ferulic acid reduces the amount of ROS produced by the enzyme-catalyzed transformation.
Average ferulic acid content in plant-delivered foods