Therapeutic Effects of Natural Antioxidant on Neurodegenerative Disease

The free radical theory of aging hypothesizes that oxygen-derived free radicals are responsible for age-related damage at the cellular and tissue levels. In a normal situation, a balanced equilibrium exists among oxidants, antioxidants and biomolecules. Excess generation of free radicals may overwhelm natural cellular antioxidant defenses, leading to oxidation and further contributing to cellular functional impairment. The identification of free radical reactions as promoters of the neurodegenerative process implies that interventions aimed at limiting or inhibiting them should be able to reduce the rate of formation of degenerative changes with a consequent reduction in the aging rate and disease pathogenesis. Although the human diet is the main source of antioxidants, medicinal plants have received increasing attention in this context. Because antioxidant therapy is vital for the elimination of free radicals and ROS prevent the propagation of tissue damage and neuronal degeneration in the face of oxidative stress, diverse compounds and a broad variety of chemical structures have been investigated as therapeutic agents for acute central nervous system lesions. Indeed, there are currently many research groups working on this theme with the objective of discovering more potent and effective compounds. Here, we provide an overview of the current knowledge of the use of several medicinal plants as antioxidant agents to reduce the cellular damage produced by neurodegenerative diseases, focusing on basic and clinical evidence.