Tag Archives: antioxidant protection

Biochemical indicators of green photosynthetic bacteria Chlorobium limicola response to Cu(2+) action

T. B. Sehin1, S. O. Hnatush1, O. D. Maslovska1,
A. A. Halushka1, Y. H. Zaritska2

1Ivan Franko National University of Lviv, Ukraine;
2State Scientific-Research Control Institute of Veterinary
Medicinal Products and Feed Additives, Lviv, Ukraine;
e-mail: SeginT@ukr.net

Received: 11 March 2019; Accepted: 29 November 2019

Photolithotrophic sulfur bacteria are involved in  biota functioning and have  a biotechnological potential for bioremediation of contaminated environment, but the mechanisms of xenobiotics, in particular of heavy metal ions damaging action and the pathways of photolithotrophic bacteria adaptation  under these conditions have not been established. In this work, the biochemical indicators of green photosynthetic bacteria Chlorobium limicola response to Cu ions were studied. C. limicola cells were incubated during one hour in buffer containing copper (II) sulfate in 0.05–0.5 mM concentrations and grown for 8 days in GSB medium. The content of Cu2+ in cells was estimated by atomic absorption spectroscopy. The activity of enzymes of antioxidant defense, photosynthetic pigments and glutathione content, indexes of lipids unsaturation and membrane viscosity as markers of  membrane fluidity were estimated. It was shown that the response of green photosynthetic bacteria C. limicola to Cu2+ action varied  depending on cations concentration. Under the influence of metal salt at 0.05 mM concentration, the activity of antioxidant enzymes, GSH/GSSG ratio, the content of photosynthetic pigments and membrane fluidity indexes were higher as compared with control. Under the increase of copper (II) sulfate concentration to 0.25 mM, the activity of antioxidant  enzymes was lower compared to the response of the cells under the influence of 0.05 mM copper (II) and the GSSG content was increased.  Under the influence of 0.5 mM copper (II) the indexes of membrane fluidity did not differ from the control, but superoxide dismutase and peroxidase activity inhibition and  the further decrease of GSH/GSSG ratio were observed followed by the highest Cu2+ cations accumulation in cells and significant decrease of  bacteria biomass growth.

Vitamin D(3) contribution to the regulation of oxidative metabolism in the liver of diabetic mice

D. O. Labudzynskyi, O. V. Zaitseva, N. V. Latyshko,
O. O. Gudkova, M. M. Veliky

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: konsumemt3@gmail.com

This work is devoted to the study of the features of oxidative metabolism of hepatocytes in diabetic mice and those under the vitamin D3 action. We found out that a 2.5-fold decrease of 25OHD3 content in the serum was caused by chronic hyperglycemia in diabetes. Intensification of the reactive oxygen species (ROS) and nitrogen monoxide (NO) production, protein oxidative modifications (detected by the contents of carbonyl groups and 3-nitrotyrosine), accumulation of diene conjugates and TBA-reactive products of lipid peroxidation, and the decreased level of free SH-groups of low molecular weight compounds in the liver were accompanied by development of vitamin D3 deficient state. It was shown that there was a decrease in the key antioxidant enzymes activity (catalase, SOD), while the activity of prooxidant enzymes NAD(P)H:quinone oxidoreductase, xanthine oxidase and NAD(P)H oxidase was increased. The identified oxidative metabolism lesions caused the elevation of the hepatocytes necrotic death that was tested for the ability of their nuclei to accumulate propidium iodide. Prolonged vitamin D3 administration (during 2 months) at a dose of 20 IU to diabetic mice helps to reduce the ROS formation and biomacromolecules oxidative damage, normalizes the antioxidant system state in the liver and increases survival of hepatocytes. The results suggest that vitamin D3 is a key player in the regulation of the oxidative metabolism in diabetes.