Tag Archives: fructose
Mild oxidative stress in fruit fly Drosophila melanogaster caused by products of sucrose splitting
B. M. Rovenko, O. V. Lushchak, O. V. Lozinsky,
O. I. Kubrak, V. I. Lushchak
Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk, Ukraine;
e-mail: olehl@pu.if.ua
The influence of 6% sucrose and equimolar mixture of glucose and fructose in larva diet on the level of oxidized proteins and lipids as well as the activity of antioxidant and associated enzymes in adult fruit fly Drosophila melanogaster was investigated. Larva growing on the diet with sucrose led to the mild oxidative stress development in adult insects, which was differently expressed in both sexes. In males mainly molecules of proteins were subjected to oxidative damages, whereas in females – lipid molecules. This is evidenced by 77% increased content of protein carbonyl groups and decreased (by 40%) level of protein SH-groups in males fed on sucrose. In females fed on sucrose the content of lipid peroxides was by 44% higher, than in individuals, hold on the diet with equimolar mixture of glucose and fructose. The oxidative stress in females was accompanied with increased activity of catalase, superoxide dismutase and thiredoxin reductase by 30, 15 and 34%, respectively. The obtained results suggest that uptake mode of glucose and fructose affects free radical processes in fruit flies.
Carbohydrate restriction in the larval diet causes oxidative stress in adult insects of Drosophila melanogaster
B. M. Rovenko, V. I. Lushchak, O. V. Lushchak
Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk, Ukraine;
е-mail address: olehl@pu.if.ua
The influence of 20 and 1% glucose and fructose, which were components of larval diet, on the level of oxidized proteins and lipids, low molecular mass antioxidant content as well as activities of antioxidant and associated enzymes in adult fruit fly Drosophila melanogaster were investigated. The restriction of carbohydrates in larval diet leads to oxidative stress in adult insects. It is supported by 40–50% increased content of protein carbonyl groups and by 60–70% decreased level of protein thiol groups as well as by a 4-fold increase of lipid peroxide content in 2-day-old flies of both sexes, developed on the diet with 1% carbohydrates. Oxidative stress, induced by carbohydrate restriction of the larval diet, caused the activation of antioxidant defence, differently exhibited in male and female fruit flies. Caloric restriction increased activity of superoxide dismutase and thioredoxin reductase associating only in males with 2-fold higher activity of NADPH-producing enzymes – glucose-6-phosphate dehydrogenase and isocitrate dehydrogenase. Carbohydrate restriction in the larval diet caused the increase of uric acid content, but the decrease in catalase activity in males. In females the values of these parameters were changed in opposite direction compared with males. The obtained results let us conclude the different involvement of low molecular mass antioxidants, glutathione and uric acid, and antioxidant enzyme catalase in the protection of male and female fruit fly macromolecules against oxidative damages, caused by calorie restriction of larval diet.
Defects in tor regulatory complexes retard aging and carbonyl/oxidative stress development in yeast Sассharomyces cerevisiae
B. V. Homza, R. A. Vasylkovska, H. М. Semchyshyn
Vassyl Stefanyk Precarpathian National University, Ivano-Frankivsk, Ukraine;
е-mail: semchyshyn@pu.if.ua
TOR signaling pathway first described in yeast S. сerevisiae is the highly conserved regulator of eukaryotic cell growth, aging and stress resistance. The effect of nitrogen sources, in particular amino acids, on the activity of TOR signaling pathway is well studied, however its relation to carbohydrates is poor understood. The aim of the present study is expanding of our understanding of potential role of TOR regulatory complexes in development of carbonyl/oxidative stress that can result from yeast cultivation on glucose and fructose. It has been shown that the level of α-dicarbonyl compounds and protein carbonyl groups increased with time of yeast cultivation and was higher in cells grown on fructose that demonstrated their accelerated aging and carbonyl/oxidative stress development as compared with cells grown on glucose. The strains defective in TOR proteins cultivated in the presence of glucose as well as fructose demonstrated lower markers of the stress and aging than parental strain. Thus these data confirmed the previous conclusion on fructose more potent ability to cause carbonyl/oxidative stress and accelerated aging in S. cerevisiae as compared with glucose. However, defects in TOR regulatory complexes retard aging and development of the stress in yeast independent on the type of carbohydrate in the cultivation medium.