The production of reactive oxygen species (ROS) is part of human metabolism and participates in various physiological mechanisms, such as cytochrome P450-mediated oxidations, regulation of smooth muscle tone, and killing microorganisms. However, when the rate of ROS production exceeds the rate of removal by cellular defenses, oxidative stress occurs, which can activate a variety of transcription factors and thus lead to the expression of a wide variety of genes, including those for growth factors, inflammatory cytokines, chemokines, cell cycle regulatory molecules, and anti-inflammatory molecules.

In recent years, increasing evidence implicates ROS in a variety of diseases and pathophysiological events including inflammation, cancer, cardiovascular disease, Alzheimer's disease, Parkinson's disease, and acute respiratory distress syndrome. This involvement suggests that antioxidant molecules can be useful to treat different diseases. Biological research on antioxidants and free radicals has produced promising results regarding new therapeutic approaches.

Natural and synthetic antioxidants can exert their effect in different ways. Antioxidant action can be attributed to direct scavenging capacity, stimulating endogenous antioxidant and/or activating physiological response.

Antioxidant therapies have emerged as an alternative for treating and/or preventing chronic degenerative diseases including cancer, cardiovascular diseases, inflammation, and neurodegenerative diseases. Potential topics include, but are not limited to:

• Free-radical scavenging properties of natural compounds
• Antiradical properties of synthetic molecules
• Design of metal chelating agents
• Biotechnology in antiradical systems
• Antioxidants as a new therapeutic approach
• Antioxidants and their benefits to health
• Endogenous antioxidants
• Antioxidants, longevity, and aging

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