Which Is the Most Significant Cause of Aging?

It becomes clearer and clearer that aging is a result of a significant number of causes and it would seem that counteracting one or several of them should not make a significant difference. Taken at face value, this suggests, for example, that free radicals and reactive oxygen species do not play a significant role in aging and that the lifespan of organisms cannot be significantly extended. In this review, I point to the fact that the causes of aging synergize with each other and discuss the implications involved.

Reflections on the Theories of Aging, of Oxidative Stress, and of Science in General. Is It Time to Abandon the Free Radical (Oxidative Stress) Theory of Aging?

Significance: Aging and oxidative stress are complex phenomena, and their understanding is of enormous theoretical and practical significance.

Recent Advances: Numerous hypotheses and theories that attempt to explain these phenomena have been developed. These hypotheses and theories compete with each other, with each claiming to be the correct one, while significantly contradicting each other.

Free radicals: how do we stand them? Anaerobic and aerobic free radical (chain) reactions involved in the use of fluorogenic probes and in biological systems.

Biologically significant conclusions have been based on the use of fluorogenic and luminogenic probes for the detection of reactive species. The basic mechanisms of the processes involved have not been satisfactorily elucidated. In the present work, the mechanism of the enzyme and photosensitized oxidation of NAD(P)H by resorufin is analyzed and appears to involve both aerobic and anaerobic free radical chain reactions.

Superoxide dismutase mimics, other mimics, antioxidants, prooxidants, and related matters.

A significant number of low molecular weight metal complexes as well as metal-free compounds that are capable of scavenging superoxide and/or other radicals and reactive species in simple systems have been proposed to be used as potential drugs in the case of various diseases and/or as antiaging agents. Some have been used or suggested to be used as diagnostic tools for the involvement of such species in biological processes. In the present work, analysis of such claims indicates that their use as specific detectors of superoxide or of other reactive oxygen species is unsupported and might be confusing.