Myricetin suppresses iron neurodegeneration

[Ironjustic]

Neuroreport. 2007 Jul 16;18(11):1181-1185. Myricetin reduces
6-hydroxydopamine-induced dopamine neuron degeneration in
rats.Ma ZG, Wang J, Jiang H, Liu TW, Xie JX. Department of
Physiology, Faculty of Medicine, Neuroscience Research
Center of Shandong Province, Qingdao University, Qingdao,
Shandong, PR China.

The effects of myricetin on 6-hydroxydopamine (6-OHDA)-induced
neurodegeneration in the substantia nigra-striatum system were
investigated. By high-performance liquid chromatography
electrochemical detection, we showed that the dopamine content
in the striatum decreased after 6-OHDA treatment, which could
be restored by myricetin. The immunohistochemistry and
semiquantitative reverse transcription-PCR studies showed that
myricetin could prevent the 6- OHDA-induced decrease of
tyrosine hydroxylase positive neurons and the tyrosine
hydroxylase mRNA expression in the substantia nigra. Perls'
iron staining study further demonstrated that myricetin
prevented the 6-OHDA-induced increase of iron-staining cells
in the substantia nigra. These results suggested that the
protective effects of myricetin on the toxicity of 6-OHDA
could be attributed to the myricetin-suppressed iron toxicity.

PMID: 17589323 [PubMed - as supplied by publisher] .
--------------------------------------------------------------
-----------------------------
Myricetin is a flavonoid that is commonly found in natural
food sources such as berries, vegetables, teas, wine and
herbs. Myricetin is considered to be an antioxidant, which
means that it is capable of eliminating free radicals within
the body. It is usually taken from the bark, leaves, and roots
of the plant known as myrica cerifera, and is completely water
soluble, which means it makes an excellent source for teas.

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

[Ironjustic]

>> On Jun 26, 7:07 pm, "ironjust...@aol.com"
>> <ironjust...@aol.com> wrote:
Neuroreport. 2007 Jul 16;18(11):1181-1185. Myricetin reduces
6-hydroxydopamine-induced dopamine neuron degeneration in
rats.Ma ZG, Wang J, Jiang H, Liu TW, Xie JX. Department of
Physiology, Faculty of Medicine, Neuroscience Research Center
of Shandong Province, Qingdao University, Qingdao, Shandong,
PR China.<<

Neuropharmacology Volume 52, Issue 6, May 2007, Pages
1385-1395

http://www.newsrx.com/article.php?articleID=3D614073

Medical News Article on Neuropharmacology

Data on neuropharmacology published by researchers at McGill
University

2007 JUL 2 -- A report, "Deficient peroxide detoxification
underlies the susceptibility of oligodendrocyte progenitors
to dopamine toxicity," is newly published data in
Neuropharmacology. According to recent research published
in the journal Neuropharmacology, "Oligodendrocyte
progenitors are highly susceptible to oxidative stress due
to their limited content of antioxidants and high iron
levels. We previously showed that iron plays a central role
in the toxicity of dopamine (DA) to oligodendrocyte
progenitors." "Here, we further explore the mechanisms
involved in DA toxicity, specifically the role of
superoxide and the glutathione system. DA...

http://tinyurl.com/2v4jb7

doi:10.1016/j.neuropharm.2007.01.019 Copyright =A9 2007
Elsevier Ltd All rights reserved. Deficient peroxide
detoxification underlies the susceptibility of oligodendrocyte
progenitors to dopamine toxicity

Sandy Hemdana and Guillermina Almazan, a, aDepartment of
Pharmacology and Therapeutics, McGill University, 3655
Promenade Sir William Osler, Room 1321, Montreal, QC H3G 1Y6,
Canada Received 10 August 2006; revised 24 January 2007;
accepted 30 January 2007. Available online 20 February 2007.

Abstract

Oligodendrocyte progenitors are highly susceptible to
oxidative stress due to their limited content of antioxidants
and high iron levels. We previously showed that iron plays a
central role in the toxicity of dopamine (DA) to
oligodendrocyte progenitors. Here, we further explore the
mechanisms involved in DA toxicity, specifically the role of
superoxide and the glutathione system. DA induces accumulation
of superoxide, membrane damage and loss in cell viability. An
iron chelator, deferoxamine, reduces superoxide accumulation.
However, a superoxide dismutase mimetic, MnTBAP, potentiates
DA toxicity, suggesting that superoxide plays an indirect role
in toxicity through dismutation to H2O2. In addition, the
glutathione (GSH) analog (GME), blocks DA-induced superoxide
accumulation, heme-oxygenase-1 (HO-1) expression and caspase-3
activation, and reduces cell death, while the glutathione
synthetase inhibitor, buthionine sulfoximine, potentiates
DA-induced HO-1 expression and cell death. Moreover, a mimetic
of the peroxide-scavenging enzyme, glutathione peroxidase
(GPx), ebselen, blocks caspase-3 activation induced by DA
alone or in combination with iron. In conclusion, superoxide
and inadequate defense by glutathione and GPx are responsible
for the susceptibility of oligodendrocyte progenitors to DA
toxicity. Furthermore, peroxides play a primary role in
toxicity induced by DA and iron.

Keywords: Oligodendrocyte progenitors; Periventricular
leucomalacia; Oxidative stress; Dopamine; Apoptosis;
Glutathione

Corresponding author. Tel.: +1 514 398 6222; fax: +1 514 398
6690.

Neuropharmacology Volume 52, Issue 6, May 2007, Pages
1385-1395

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

>
> The effects of myricetin on 6-hydroxydopamine
> (6-OHDA)-induced neurodegeneration in the substantia
> nigra-striatum system were investigated. By high-performance
> liquid chromatography electrochemical detection, we showed
> that the dopamine content in the striatum decreased after
> 6-OHDA treatment, which could be restored by myricetin. The
> immunohistochemistry and semiquantitative reverse
> transcription-PCR studies showed that myricetin could
> prevent the 6- OHDA-induced decrease of tyrosine hydroxylase
> positive neurons and the tyrosine hydroxylase mRNA
> expression in the substantia nigra. Perls' iron staining
> study further demonstrated that myricetin prevented the
> 6-OHDA-induced increase of iron-staining cells in the
> substantia nigra. These results suggested that the
> protective effects of myricetin on the toxicity of 6-OHDA
> could be attributed to the myricetin-suppressed iron
> toxicity.
>
> PMID: 17589323 [PubMed - as supplied by publisher] . -------
> ------------------------------------------------------------
> --------=
--=AD---------------
> Myricetin is a flavonoid that is commonly found in natural
> food sources such as berries, vegetables, teas, wine and
> herbs. Myricetin is considered to be an antioxidant, which
> means that it is capable of eliminating free radicals within
> the body. It is usually taken from the bark, leaves, and
> roots of the plant known as myrica cerifera, and is
> completely water soluble, which means it makes an excellent
> source for teas.
>
> Who loves ya. Tom
>
> Jesus Was A Vegetarian!http://jesuswasavegetarian.7h.com
>
> Man Is A Herbivore!http://tinyurl.com/a3cc3
>
> DEAD PEOPLE WALKINGhttp://tinyurl.com/zk9fk