The antitumor activity of 5-(5¢,6¢-benzocoumaro-3¢-yl)methylaminouracil (BCMU) and its liposomal medicinal form was studied in comparison to 5-fluorouracil (5-FU), a well-known antitumor drug widely used in oncological practice. The half-lethal dose of BCMU is 14.8 ± 4.2 mg/kg, while the optimum effective dose of the drug is 6 mg/kg. In this dose, BCMU combines low toxicity with significant antitumor activity, which is manifested by increased tumor growth inhibition (TGI) at a 19% increase in the lifetime (LT) of experimental animals. The antitumor activity of the liposomal form of BCMU is quantitatively and qualitatively superior to that of the nonmodified compound and 5-FU, which is manifested by the most pronounced TGI value and by a significant LT increase.

The relationship between the quantitative ratio of redox forms of ubiquinone and the degree of free radical damage to mitochondrial proteins in rat liver against the background of nutritional imbalance was investigated. The animals were divided into the following experimental groups: I – animals receiving full-value semi-synthetic ration (control group); II – animals receiving high-sucrose diet; III – animals receiving low-protein high-sucrose diet. The content of total and oxidized ubiquinone was determined spectrophotometrically at 275 nm, the content of reduced ubiquinone was determined by the difference between the content of total and oxidized ubiquinone. The intensity of the oxidative modification of proteins was assessed by the accumulation of carbonyl derivatives in the reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH), the content of free SH-groups was assessed by using the Elman reagent. It was found that the most pronounced decrease in the content of total ubiquinone (almost twice) and the redistribution of its redox forms (reduction of the content of reduced ubiquinone by 7.2 times against the background of an increase in the level of oxidized ubiquinone by 2 times) in rat liver mitochondria is observed in animals that received a diet high in sucrose against the background of alimentary protein deprivation. In addition, the animals of this group showed the most pronounced free radical oxidation of mitochondrial proteins, as evidenced by a 3.5-fold increase in the content of carbonyl derivatives and a 2.6-fold decrease in the content of free protein SH- groups. It was shown that nutritional protein deficiency is a critical factor affecting the intensity of free radical processes in mitochondria. The established changes in the ratio of the redox forms of ubiquinone and the degree of oxidative modification of mitochondrial proteins in rat liver could be considered as prerequisites for deepening the energy imbalance and violation of the functional activity of mitochondria under conditions of nutritional imbalance.

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