FIGURE 2.

Schematic diagram representing the antioxidant properties of plant-derived bioactive compounds in the recovery of oxidative stress-mediated changes in the aging brain. Age-associated cellular and biochemical changes such as mitochondrial dysfunction, and decline of antioxidant enzyme systems lead to the generation of excessive reactive free radicals. These free radicals cause changes in the biological macromolecules (lipid peroxidation, oxidation of protein, and nucleic acid) and thus facilitate cellular or mitochondrial membrane damage, modified protein accumulation, double-stranded DNA break, and epigenetic modifications. These oxidative stress-mediated damages ultimately lead to neurodegeneration and decline of cognitive functions during aging or associated neurodegenerative diseases. Supplementation of plant-derived bioactive compounds ameliorates the age-associated neurodegeneration and cognitive dysfunctions by increasing the activities of antioxidant enzymes and decreasing the oxidative stress-induced damages to biological macromolecules.