The impacts of water deficit and melamine salt of bis(oximethyl)phosphonic acid (melaphen) on the fatty acid (FA) composition of membrane lipids and energy metabolism in mitochondria of 5-day-old pea (Pisum sativum L., cv. Flora-2) seedlings were studied. Insufficient watering resulted in the accumulation of saturated and a decrease in the content of unsaturated FAs with 18 and 20 carbon atoms. Seed treatment with 3 × 10⁻¹⁰ M melaphen prevented these changes in the FA composition in the mitochondrial membrane lipids. Changes in the FA compositions of membrane lipids were correlated with changes in energy metabolism in mitochondria: the efficiency of oxidative phosphorylation and the rate of NAD-dependent substrate oxidation in the presence of ADP and FCCP (carbonyl cyanide-p-trifluoromethoxyphenylhydrazone) were reduced. A close correlation was observed between changes in the highest rates of NAD-dependent substrate oxidation and the relative content of FAs with 18 (r = 0.76489) and 20 (r = 0.9637) carbon atoms. The regulatory role of C₁₈ and C₂₀ unsaturated FAs in the mitochondrial energy metabolism of pea seedlings is discussed.

The increased generation of reactive oxygen species (ROS) by mitochondria under stress conditions leads to lipid peroxidation (LPO) as a consequence of the ROS interactions with polyunsaturated fatty acids in the lipid bilayer of cell membranes, causing their damage. It was assumed that chemical preparations that reduce the excessive ROS generation by mitochondria should exhibit protecting properties under oxidative-stress conditions. In this context, the antioxidants resveratrol (RSV) and 2-ethyl-6-methyl-3-hydroxypyridine N-acetylcysteinate (NAC-3-HP) were examined as potential chemical protectors upon the exposure to stress, able to maintain the functional state of mitochondria.

The antiradical properties and biological activity of natural polyphenol—resveratrol—are studied. The chemiluminescence method recorded high values of the antiradical activity of this drug. Using the model system, it is shown that the drug in the concentration range of 10^–5 to 10^–12 M prevented the activation of lipid peroxidation (LPO) in the mitochondrial membranes of pea seedlings, which could indicate the presence of antistress properties in this preparation, which are studied under conditions of water deficiency, which causes LPO and leads to mitochondrial swelling. Resveratrol seed treatment (3 × 10^–5 M) under these conditions leads to a decrease in the number of swollen mitochondria and the appearance of small mitochondria, which, perhaps, is a sign of the activation of mitochondrial biogenesis. Resveratrol, which prevents LPO, helps maintain the functional state of mitochondria and activates the energy metabolism by increasing their number, which is reflected in the physiological parameters: the drug prevents a decrease in the growth rate of pea seedlings in conditions of water deficiency. Based on the data obtained, it is assumed that the drug has antistress properties in the concentration range in which it exhibits an antioxidant effect.

The antiradical features and biological activity of N-acetylcysteinate 2-ethyl-6-methyl-3-hydroxypyridine have been studied. The high antiradical activity of this drug has been shown by the...

Background: Stress factors lead to a shift in the antioxidant-prooxidant relationship, allowing an increase in the generation of reactive oxygen species (ROS) by mitochondria, which results in the development of oxidative stress. Consequently, it is possible to put forward an as-sumption that drugs which reduce the excessive generation of ROS by these organelles should in-crease the body's resistance to stress factors. Antioxidants can be used as such drugs. In this regard, the aim of this work was to study the bioenergetics characteristic of mitochondria under stress con-ditions and under the action of 2-ethyl-6-methyl-3-hydroxypyridinium hydroxybutanedioate (eth-oxidol). Methods: The antiradical activity of the drug was evaluated by the chemiluminescent method (CL). The functional state of the mitochondria was studied with reference to the level of lipid peroxida-tion by the spectrofluorimetry and in terms of fatty acid composition of mitochondrial membranes using the chromatography technique. The study of mitochondrial morphology was performed em-ploying the method of atomic force microscopy. Results: The injection in mice of ethoxidol at a dose of 10-5 mol/kg for 7 days led to the prevention of the stress-induced increase in the intensity of LPO in the membranes of the mitochondria, and swelling of these organelles; it also prevented a decrease in the content of unsaturated fatty acids, containing 18 and 20 carbon atoms. At the same time, ethoxidol increased the life expectancy of mice by 3.0-4.2 times in conditions of various types of hypoxia. Conclusion: The adaptogenic properties of ethoxidol can be attributed to its antiradical and antiox-idant properties.

Background: The binding of free iron ions in the composition of nitrosyl complexes is probably one of the mechanisms of the antioxidant action of nitric oxide. The study of the protective properties of nitric oxide is often carried out using exogenous NO donors. In our work, we used nitric oxide donor - sodium μ2-dithiosulfate-tetranitosyldiferrate tetrahydrate (TNIC-thio). Objective: The aim of our work was to investigate the possibility of using TNIC-thio to increase the resistance of plants to stress factors. Since the implementation of anti-stress programs requires a lot of energy expenditure, we studied the functional state of the mitochondria of pea seedlings under conditions of water deficiency and treatment with TNIC-thio. Materials and Methods: The functional state of the mitochondria was studied as per the level of lipid peroxidation by the spectrofluorimetry, by a fatty acid composition of mitochondrial membranes with the chromatography technique and by the morphology of mitochondria with the atomic force microscopy. Results: Water deficiency has caused changes in the Fatty Acid (FA) composition, which manifested themselves in increasing the content of saturated FAs and decreasing the content of unsaturated FAs containing 18 and 20 carbon atoms. Treatment of pea seeds with 10–8 M TNIC-thio under these conditions led to the prevention of LPO, prevention of changes in the FA composition of mitochondrial membranes and reduction in the number of swollen organelles. Conclusion: It can be assumed that the protective effect of TNIC-thio is due to the preservation of the functional state of the mitochondria.