VIII
ABSTRACT
Dissertation of Master’s Degree
Post-Graduate Course in Toxicological Biochemistry
Federal University of Santa Maria, RS, Brazil
Evaluatin of antioxidant properties of quercitrin against lipid peroxidation
AUTHOR: Caroline Wagner
ADVISOR: Cristina Wayne Nogueira
CO-ADVISOR: João Batista Teixeira da Rocha
Reactive oxygen species have been associated with a pathophysiology of
neurodegenerative disorders
such
as Parkinson’s and Alzheimer`s disease.
Flavonoid compounds show protective action against oxidative mechanisms in
different in vivo and in vitro models, which seems to be linked to their antioxidant
properties. In the present study, we examine the protective effects of quercitrin,
a glycoside form of quercetin, against lipid perixidation induced by different pro-
oxidant agents. For that TBARS production was stimulated by the incubation of
rat brain homogenate with Fe2+, Fe2+ plus EDTA, quinolinic acid (QA), sodium
nitroprusside (SNP) and potassium ferricyanide ([Fe (CN)
6
]
3−
). Quercitrin was
able to prevent the formation of TBARS induced by pro-oxidant agents tested;
however, it was more effective against potassium ferricyanide ([Fe (CN)
6
]
3−
)than
quinolinic acid and sodium nitroprusside than Fe
2+
and, Fe
2+
plus EDTA. The
effect of quercitrin on the Fenton reaction was also investigated (deoxyribose
degradation). Quercitrin caused a significant decrease in deoxyribose
degradation. Taken together, the data presented here indicate that quercitrin
exhibits a scavenger and antioxidant role, and these effects probably are
mediated via different mechanisms, which may involve the negative modulation
of the Fenton reaction and N-methyl-D-aspartate (NMDA) receptor.
Keywords
: Quercitrin, Oxidative stress, Quinolinic acid, TBARS, Deoxyribose
degradation, Flavonoids, Sodium nitroprusside, Fenton reaction.