Organismal Aging and Oxidants beyond Macromolecules Damage

Area of Science:

• Gerontology
• Cellular Biology
• Oxidative Stress Research

Background:

• The Free Radical Theory of Aging posits that accumulated oxidant damage drives aging.
• Antioxidant supplements have shown limited efficacy in improving healthspan, challenging this theory's sole focus on damage.
• Emerging evidence highlights the role of cellular senescence in aging, independent of direct oxidant damage.

Purpose of the Study:

• To review current knowledge on the roles of oxidants and cellular senescence in organismal aging.
• To propose a new perspective on the Free Radical Theory of Aging.
• To investigate oxidants as potential regulators of cellular senescence pathways.

Main Methods:

• Literature review of studies on oxidants, oxidative stress, and cellular senescence in aging.
• Analysis of experimental data linking oxidants to macromolecular damage and senescence.
• Theoretical integration of oxidant signaling in senescence with existing aging theories.

Main Results:

• While oxidant-mediated macromolecular damage is a known aging factor, its direct link to health benefits via supplements is weak.
• Cellular senescence is increasingly recognized as a significant contributor to the aging process.
• Oxidants may act as signaling molecules that induce cellular senescence, beyond causing direct damage.

Conclusions:

• The Free Radical Theory of Aging may need revision to include the role of oxidants in inducing cellular senescence.
• A modified theory suggests organisms age due to oxidant-dependent damage and oxidant-induced senescent characteristics.
• Understanding oxidants' dual role in damage and senescence is crucial for future aging research and interventions.