Philos Trans R Soc Lond B Biol Sci. 2005 Dec 29; 360(1464): 2355–2372.
Published online 2005 Nov
3. doi: 10.1098/rstb.2005.1770
PMCID: PMC1569588
Oxidative
stress and ageing: is ageing a cysteine deficiency syndrome?
氧化壓力與老化:難道老化是缺乏 半胱胺酸 所引起的症候群嗎?
Wulf Dröge
Division of Redox Physiology and Aging Research, Deutsches
Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany 德國
資訊來源:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1569588/
#湯偉晉挑選的醫學論文
ABSTRACT
Reactive oxygen species (ROS) are
constantly produced in biological tissues and play a role in various signaling pathways. Abnormally high ROS
concentrations cause oxidative stress associated with tissue damage and dysregulation of physiological signals. There is growing evidence that oxidative stress increases with age. It has also been shown that the life span of worms, flies and mice can be significantly increased by mutations
which impede the insulin receptor signaling cascade. Molecular studies revealed
that the insulin-independent basal activity of
the insulin receptor is increased by ROS and
downregulated by certain antioxidants. Complementary clinical studies confirmed
that supplementation
of the glutathione precursor cysteine decreases
insulin responsiveness in the fasted state. In several clinical trials, cysteine supplementation improved skeletal muscle functions,
decreased the body fat/lean body mass ratio, decreased plasma levels of the inflammatory
cytokine tumour necrosis factor α (TNF-α), improved immune functions, and increased plasma albumin
levels. As all
these parameters degenerate with age, these findings suggest: (i) that loss of youth,
health and quality of life may be partly explained by a deficit in cysteine and
(ii) that the dietary consumption of cysteine is generally suboptimal and everybody
is likely to have a cysteine deficiency sooner or later.
Keywords: cysteine in
vivo, redox status, muscle functions, immune functions, inflammatory cytokines,
insulin signaling, aging
... other content omitted for brevity ...
Properly done, cysteine
supplementation can reasonably be expected to improve the quality of life in old
age. With the availability of novel cysteine delivery systems with minimum
amounts of calories, which
are superior to any of the naturally available cysteine sources, it is conceivable that even the maximum
human life span may be increased beyond the previous limit.
ACKNOWLEDGMENTS
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