Ironjustic
Sun, Sep-23-07, 17:16
Phenolic-rich juice prevents DNA single-strand breakage and
cytotoxicity caused by tert-butylhydroperoxide in U937 cells:
the role of iron chelation Francisco J. Garcia-Alonsoa,4,
Andrea Guidarellib, Mar=C4=B1=C3=A1 J. Peria= goaa Food
Science and Nutrition Department, Faculty of Veterinary,
University of Murcia, Campus de Espinardo, 30071 Murcia,
Spainb Institute of Pharmacology and Pharmacognosy, University
of Urbinob Carlo BoQ, 61029 Urbino (PU), Italy Received 27
April 2006; received in revised form 16 August 2006; accepted
22 August 2006 Abstract The antioxidant potential of phenolic
compounds is generally linked to their ability to scavenge
free radicals. However, in addition to their
radical-scavenging activity, phenolic compounds can chelate
metal ions, such as iron, to prevent their participation in
Fenton-type reactions,which lead to the formation of free
radicals. The aim of the present study was to evaluate the
ability of a phenolic-rich juice made from grapes, cherries
and berries to protect human myeloid leukemia (U937) cells
from oxidative stress caused by tert- butylhydroperoxide
(tB-OOH). Preincubation of cells with extracts of the
phenolic-rich juice at different concentrations (0=E2=80=93200
AM ferul= ic acid equivalents) for 3 h partially prevented
cell death and abolished the DNA cleavage induced by tB-OOH.
Moreover, when preincubating cells with the 100-AM juice
extract (the dose that diminished cell death by around 50%),
the partial prevention of tB-OOH-induced formation of reactive
oxygen species (ROS) and mitochondrial permeability transition
pore opening was observed. The radical scavenger antioxidant
N,NV-diphenyl-1,4-phenylene-diamine (DPPD) and the
intracellular iron chelator o-phenanthroline (o-Phe) were also
tested to know whether protective effects depended on
radical-scavenging or iron-chelating activities. o-Phe
prevented cell death, DNA cleavage and ROS generation, whereas
DPPD only prevented cell death, suggesting that phenolics in
the juice afforded protection against induced oxidative
stress, most probably by means of an iron-chelating mechanism.
D 2007 Elsevier Inc. All rights reserved. Keywords: Phenolics;
Iron chelators; Radical scavengers; DNA single- strand
breakage; Cytotoxicity; tert-Butylhydroperoxide
http://tinyurl.com/2cq8pl
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
cytotoxicity caused by tert-butylhydroperoxide in U937 cells:
the role of iron chelation Francisco J. Garcia-Alonsoa,4,
Andrea Guidarellib, Mar=C4=B1=C3=A1 J. Peria= goaa Food
Science and Nutrition Department, Faculty of Veterinary,
University of Murcia, Campus de Espinardo, 30071 Murcia,
Spainb Institute of Pharmacology and Pharmacognosy, University
of Urbinob Carlo BoQ, 61029 Urbino (PU), Italy Received 27
April 2006; received in revised form 16 August 2006; accepted
22 August 2006 Abstract The antioxidant potential of phenolic
compounds is generally linked to their ability to scavenge
free radicals. However, in addition to their
radical-scavenging activity, phenolic compounds can chelate
metal ions, such as iron, to prevent their participation in
Fenton-type reactions,which lead to the formation of free
radicals. The aim of the present study was to evaluate the
ability of a phenolic-rich juice made from grapes, cherries
and berries to protect human myeloid leukemia (U937) cells
from oxidative stress caused by tert- butylhydroperoxide
(tB-OOH). Preincubation of cells with extracts of the
phenolic-rich juice at different concentrations (0=E2=80=93200
AM ferul= ic acid equivalents) for 3 h partially prevented
cell death and abolished the DNA cleavage induced by tB-OOH.
Moreover, when preincubating cells with the 100-AM juice
extract (the dose that diminished cell death by around 50%),
the partial prevention of tB-OOH-induced formation of reactive
oxygen species (ROS) and mitochondrial permeability transition
pore opening was observed. The radical scavenger antioxidant
N,NV-diphenyl-1,4-phenylene-diamine (DPPD) and the
intracellular iron chelator o-phenanthroline (o-Phe) were also
tested to know whether protective effects depended on
radical-scavenging or iron-chelating activities. o-Phe
prevented cell death, DNA cleavage and ROS generation, whereas
DPPD only prevented cell death, suggesting that phenolics in
the juice afforded protection against induced oxidative
stress, most probably by means of an iron-chelating mechanism.
D 2007 Elsevier Inc. All rights reserved. Keywords: Phenolics;
Iron chelators; Radical scavengers; DNA single- strand
breakage; Cytotoxicity; tert-Butylhydroperoxide
http://tinyurl.com/2cq8pl
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