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Medical Forum / General / General / July 2006

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Oxidative Stress and Iron Imbalance in neurodegeneration

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ironjustice@aol.com - 04 Jul 2006 22:49 GMT
http://www.medicalnewstoday.com/medicalnews.php?newsid=41422

Mark A. Smith
Oxidative Stress and Iron Imbalance in Alzheimer Disease: How Rust
Became the Fuss!
Abstract: The role of oxidative stress in the pathogenesis of Alzheimer
disease has gone from epiphenomena to phenomena. This transition, from
disregarded to accepted theory, started in the early-mid 1990s and was
accelerated by a number of reports in the literature showing that
redox-active sources of transition metals, such as iron, were increased
in the brain at early stages of disease. As such, it became apparent
that not only was there damage but, more importantly, the machinery to
exact such damage was ever present. In this review, the author
chronicles his personal perspective on the past, present, and future of
oxidative stress in Alzheimer disease.

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Source: Emory University Health Sciences Center

Scientists Discover Possible Link Between Oxidative Stress And
Non-hereditary Degenerative Disease
ATLANTA--The irreversible neurological degeneration associated with
Parkinson's and Alzheimer's diseases may be the consequence of
oxidative stress--the imbalance of antioxidants and pro-oxidants in
cells. This imbalance results in an excess of reactive oxygen
species--harmful oxygen-containing molecules that can cause damage to
proteins. In the April 21 issue of the Journal of Biological Chemistry,
scientists from the Emory University School of Medicine report that the
protein DJ-1 is oxidatively damaged in non-hereditary (sporadic)
Parkinson's disease.

While scientists do not know the function of DJ-1, they have previously
identified abnormalities in DJ-1 that directly cause hereditary
(familial) Parkinson's disease. About 10 percent of Parkinson's disease
cases are hereditary forms caused by either a genetic deletion or
mutations that result in amino acid substitutions, which can
dramatically affect protein structure or function.

The cause of the 90 percent of Parkinson's Disease cases not influenced
by genetics has remained more of a mystery. Lian Li, PhD, is associate
professor of pharmacology at Emory University School of Medicine and
lead author of this study, which was funded by a grant from the
National Institutes of Health. "One popular theory has suggested that
these sporadic cases result from exposure to environmental toxins, such
as herbicides or pesticides," she says. "Previous research has
indicated that these toxins lead to oxidative stress. While oxidative
stress does occur naturally as humans age, further oxidation caused by
toxins may overwhelm the body's antioxidants."

Until now, attempts to link environmental toxins to oxidation and
neurological disorders have been only somewhat successful, in part
because scientists have been unable to identify the molecular target of
oxidation. "This theory [that toxins cause oxidative stress] has been
around for a long time," says Dr. Li. "But what's been damaged by this
oxidative stress?"

Aware of the connection between DJ-1 mutations and familial Parkinson's
disease, Dr. Li and her collaborators examined the oxidation levels of
the protein in sporadic cases. Their hypothesis that DJ-1 was the
missing link proved to be correct: DJ-1 in patients who had Parkinson's
disease showed signs of oxidative damage, including structural changes
as the protein accumulated additional oxygen molecules (carbonylation
and methonine oxidation).

These modifications to DJ-1 caused by the oxidative stress are
irreversible and irreparable. Like familial Parkinson's disease, the
structural changes to the DJ-1 protein in sporadic Parkinson's disease
signal an abnormality, leading to the eventual degradation and loss of
the protein. "The protein unfolds and cannot function normally," Dr. Li
explains. "Not recognizing the unfamiliar shape, the protein is broken
down by the cell. The end result is the same: you lose your protein.
Any mutation or modification causing this protein to lose its function
will then lead to neurodegeneration in Parkinson's disease."

Now that Dr. Li and her team are clear that a relationship between DJ-1
and neurodegeneration exists, they are preparing to extend their
examination into the protein's role. Based on biochemical analysis, Dr.
Li believes DJ-1 may serve as a protease, activating and deactivating a
protein by cleaving the bonds that connect its amino acids. Dr. Li is
also currently exploring the possibility that DJ-1 may serve as an
antioxidant, and that when mutated or damaged, the protein cannot
defend the cell.

Future information about the role of DJ-1 may enable the development of
drugs to specifically target the protein, perhaps stopping or reversing
Parkinson's disease or Alzheimer's disease, which also may be impacted
by the oxidation of DJ-1. In the meantime, says Dr. Li, people looking
to prevent neurological degeneration might do well by looking to the
kitchen cabinet, not the pharmacy: green tea and vitamin C supplements
are two bountiful sources of antioxidants.

Who loves ya.
Tom

Jesus Was A Vegetarian!
http://jesuswasavegetarian.7h.com

Man Is A Herbivore!
http://tinyurl.com/a3cc3


DEAD PEOPLE WALKING
http://tinyurl.com/zk9fk
outsor@citynet.net - 04 Jul 2006 23:19 GMT
I thought the one about ""Obsessive-compulsive disorder" was more
interesting.  What do you think?
monty1945@lycos.com - 05 Jul 2006 07:51 GMT
The studies that also point out how polyunsaturated fatty acids and/or
their metabolites are involved are the most interesting of all !
ironjustice@aol.com - 05 Jul 2006 19:42 GMT
> The studies that also point out how polyunsaturated fatty acids and/or
> their metabolites are involved are the most interesting of all !

Sooooo .. green vegetables in YOUR .. world .. are .. THE .. bad things
.. ?

The alpha-linolenic acid content of green vegetables commonly available
in Australia.
Pereira C, Li D, Sinclair AJ
Int J Vitam Nutr Res. 2001 Jul ; 71(4): 223-8

Green vegetable consumption has long been considered to have health
benefits mainly due to the vitamins, minerals and phytonutrients (such
as vitamin C, folate, antioxidants etc) contained in a vegetable-rich
diet. Additionally, green vegetables are known to contain a relatively
high proportion of omega-3 polyunsaturated fatty acids (PUFAs),
primarily in the form of alpha-linolenic acid (18:3n-3). However, there
are no data available on the fatty acid composition and concentration
of green vegetables commonly consumed in Australia. The present study
determined the fatty acid content of 11 green vegetables that are
commonly available in Australia. The total fatty acid concentrations of
the vegetables under study ranged from 44 mg/100 g wet weight in
Chinese cabbage to 372 mg/100 g in watercress. There were three PUFAs
in all vegetables analyzed; these were 16:3n-3, 18:2n-6, and 18:3n-3
fatty acids. Sample vegetables contained significant quantities of
16:3n-3 and 18:3n-3, ranging from 23 to 225 mg/100 g. Watercress and
mint contained the highest amounts of 16:3n-3 and 18:3n-3, and parsley
had the highest amount of 18:2n-6 in both percentage composition and
concentration. Mint had the highest concentration of 18:3n-3 with a
value of 195 mg/100 g, while watercress contained the highest
concentration of 16:3n-3 at 45 mg/100 g. All 11 green vegetables
contained a high proportion of PUFAs, ranging from 59 to 72% of total
fatty acids. The omega-3 PUFA composition ranged from 40 to 62% of
total fatty acids. Monounsaturated fatty acid composition was less than
6% of total fatty acids. The proportion of saturated fatty acids ranged
from 21% in watercress and mint to 32% of total fatty acids in Brussels
sprouts. No eicosapentaenoic and docosahexaenoic acids were detected in
any of the samples. Consumption of green vegetables could contribute to
18:3n-3 PUFA intake, especially for vegetarian populations.

Who loves ya.
Tom

Jesus Was A Vegetarian!
http://jesuswasavegetarian.7h.com

Man Is A Herbivore!
http://tinyurl.com/a3cc3

DEAD PEOPLE WALKING
http://tinyurl.com/zk9fk
 
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