Tag Archives: carbonyl derivatives
Free radical processes in the liver mitochondria of rats exposed to diethyl phthalate
O. V. Ketsa*, A. P. Husliakova, M. M. Marchenko
Yuriy Fedkovych Chernivtsi National University, Chernivtsi, Ukraine;
*e-mail: o.ketsa@chnu.edu.ua
Received: 11 October 2023; Revised: 28 November 2023;
Accepted: 01 February 2024; Available on-line: 26 February 2024
Diethyl phthalate (DEF) is a synthetic chemical widely used as plasticizer and additive in personal care and pharmaceutical products. Low-dose exposure to this xenobiotic over a long period contributes to its intake into the human body in a high doses. To date, studies of DEF influence on free radical processes in liver cells, in which it is not only metabolized but can also have a prooxidant effect, remain limited. The aim of our research was to determine ROS formation, the intensity of oxidative modification of proteins (OMP) and proteolytic activity in the mitochondrial fraction of liver tissue of rats exposed to diethyl phtalate. The experimental white outbred rats were divided into three groups: I – intact animals (control), II and III – rats administered DEF orally for three weeks at a doses that reflect the dose levels received by humans, namely 2.5 and 5.4 mg/kg b.w. respectively. The animals were euthanized on the 14th and 21st day after xenobiotic administration. The mitochondrial fraction from the rat liver was isolated and the level of superoxide and hydroxyl radicals, protein carbonyl derivatives, SH-groups and Schiff bases was determined. Proteolytic activity was assessed in the test of hemoglobin cleavage. It was shown that administration of DEF in a dose of 2.5 mg/kg initiated ROS generation and OMP intensification in the rat liver mitochondria only with prolonged administration for 21 days, whereas its administration in a dose of 5.4 mg/kg led to intensification of these processes already on day 14th followed by further amplification on day 21st. The activity of proteolytic enzymes in the mitochondrial fraction was found to be depended on the degree of DEF–induced OMP and was increased with minor OMP intensification but decreased with significant intensification of proteins free radical oxidation.
The NADH-ubiquinone reductase and succinate dehydrogenase activity in the rat kidney mitochondria under the conditions of different protein and sucrose content in the diet
O. M. Voloshchuk*, М. S. Ursatyy, G. P. Kopylchuk
Yuriy Fedkovych Chernivtsi National University, Institute of Biology, Chemistry and Natural Resources, Ukraine;
*e-mail: o.voloschuk@chnu.edu.ua
Received: 11 November 2021; Accepted: 21 January 2022
The NADH-ubiquinone reductase (EC 7.1.1.2) and succinate dehydrogenase (EC 1.3.5.1) activity, the levels of total ubiquinone and its redox forms, and the degree of oxidative modification of mitochondrial proteins in the rat kidney were investigated. It was found that when consuming a low-protein diet there is a decrease in NADH-ubiquinone reductase and succinate dehydrogenase activity by 1.4-1.7 times, a 20% decrease in total ubiquinone and a quantitative redistribution of its oxidized and reduced form with a predominance of oxidized form. Under the studied conditions, there is no accumulation of carbonyl derivatives, but the level of free SH-groups is significantly reduced compared with control. At the same time, in animals consuming a high-sucrose diet there is an increase in NADH-ubiquinone reductase and succinate dehydrogenase activity by 1.5-2 times and maintenance of the total ubiquinone at the control level against the background of redistribution of its redox forms, namely a decrease in reduced ubiquinone and an increase in oxidized ubiquinone on average by 1.5 times. In addition, there is an intensification of the reactions of free radical damage of mitochondrial proteins in kidney cells, as evidenced by an increase in the level of carbonyl derivatives and a significant decrease in the level of free protein SH-groups by approximately 1.4-1.5 times. The most pronounced changes in the studied indicators are found in animals that consumed a low-protein/high-sucrose diet. In particular, an excessive consumption of sucrose on the background of protein deficiency is accompanied by a reduction of NADH-ubiquinone reductase and succinate dehydrogenase activity by 1.7-2 times, a decrease in total ubiquinone level by approximately 1.4 times, and a two-fold decrease in reduced ubiquinone against the background of intensification of the free radical oxidation of mitochondrial proteins, which can be considered as a prerequisite for the impairment of the renal function under the conditions of carbohydrate-protein imbalance.
Proteins oxidative modification and antioxidant enzymes activity in the liver mitochondria of rats under laser irradiation and administration of ω-3 polyunsaturated fatty acids
O. V. Ketsa*, M. O. Zelinska, M. M. Marchenko
Fedkovich Chernovtsy National University, Chernovtsy, Ukraine;
*e-mail: o.ketsa@chnu.edu.ua
Received: 12 August 2021; Accepted: 21 January 2022
The effect of laser irradiation of rats combined with omega-3 polyunsaturated fatty acids (ω-3 PUFA) administration on the proteins oxidative modification and superoxide dismutase and catalase activity in the mitochondrial fraction of the liver was investigated. Animals were irradiated with a 650 nm laser diode in the abdomen daily for 4 min at the distance of 10 cm from the skin surface. ω-3 PUFA were administered per os at a daily dose of 120 mg/kg of the body weight. Fatty acids in the fish oil were identified by gas chromatography. Animals were divided into five groups (12 animals in each group): I – intact rats (control); II – rats exposed to the daily laser irradiation for 7 or 14 days ; III – rats that received ω-3 PUFA two hours after irradiation; IV – rats that received ω-3 PUFA two hours before irradiation; V – rats that received ω-3 PUFA for 7 days before irradiation. The mitochondrial fraction of rat liver was obtained by differential centrifugation. The increase in the content of protein carbonyl derivatives and a decrease of protein thiol groups in the liver mitochondrial fraction were detected after seven-day laser irradiation of rats. As the duration of irradiation increases, superoxide dismutase and catalase activity was decreased, indicating a depletion of mitochondrial antioxidant reserves. No antioxidant effect was observed when ω-3 PUFA were administrated after laser irradiation and a slight antioxidant effect was shown when ω-3 PUFA were administrated two hours before irradiation. Preliminary seven-day administration ω-3 PUFA before laser irradiation was the most effective, as it reduced the level of protein carbonyl derivatives and O2•--generation, increased proteins SH-groups content and antioxidant enzymes activity.