Autor(es):
Conim, A 
; Alves-Pereira, I ; Ferreira, R
Data: 2010
Identificador Persistente: http://hdl.handle.net/10174/6516
Origem: Repositório Científico da Universidade de Évora
Assunto(s): UEME3; Red Fruit; BY4741; NADHred; NADPH(P450) reductase
Descrição
Vanadium pentoxide, V2O5 (V5+) behaves as powerful oxidizing
agent which participates in free radicals generation. Although some
biological studies reveals that vanadium compounds have mutagenic
and genotoxic effects, other authors reveal that vanadium
exerts antitumoral effects by activating signaling pathways leading
to apoptosis or inducing xenobiotic metabolizing enzymes which degrade active carcinogens. In other hand, several industrial processes
contributes to increase the vanadium concentration in the
environment, making it a pollutant. Following from the above, the
main objective of this work was to evaluate the survival and enzymatic
antioxidant response to V2O5, by Saccharomyces cerevisiae:
UEME3,
a wildtype
strain; Red Fruit, a wine commercial strain and
a BY4741 strain. Cells at midexponential
phase were inoculated in
YEPD medium with 2% (w/v) glucose and incubated during 72 h in
a water bath with orbital stirring, at 28 ◦C, in the absence or in the
presence of 2mMV2O5. Samples from each treatment were used to
obtain growth curves and to determine mitochondrial, microsomal
and cytosolic fractions, used for determination of NADH cit c reductase,
(NADHred), NADPH(P450) reductase, (NADPH(P450)red),
glutathione peroxidase (GPx), glucose6phosphate
dehydrogenase
(G6PD) and catalase T (CAT T) activities. The results show that
V2O5 inhibited cell growth of any yeast strains in study, although
drastically pronounced in the case of BY4741 strain. Inhibition
of the respiratory chain at the NADHred activity, as well as the
activation of the microsomal electrons transport, via microsomal
NADPH(P450)red, by vanadium appear to be important sources of
ROS and toxicity for studied strains. However higher levels of CAT
T in native and wine commercial strains are vital to significantly
prevent cell death by V2O5, since GPx decrease significantly.
