The state of the prooxidant and antioxidant systems of the rat under the single application of some methyl derivatives of pyridine N-oxide – Ivin and Poteitin

Abstract

АBSTRACT. Previously, it was shown that pyridine N-oxide based plant growth regulators (PGR) Ivin and Poteitin when combined with pesticides reduce the acute and subchronic toxicity of pesticides for mammals, have a hepatoprotective effect, contribute to the reduction of mutagenic activity, in particular, of Cyclophosphane and Dioxidin cytostatics (Vasetska O.P., 2017, Vasetska O.P. et al., 2020, 2021). It is possible that a wide range of their biological effects may be associated with the activation of the body’s protective systems, in particular the antioxidant system. The effect of these PGRs on the state of the pro-oxidant and antioxidant systems is not sufficiently clarified. Therefore, an important issue for preventive toxicology is the study of the nature of the effect of PGR on the state of the body’s pro-oxidant and antioxidant systems, which will contribute to the development of preventive measures to preclude acute and chronic intoxications with pesticides. Aim. To find out the state of the body’s pro-oxidant and antioxidant systems under a single oral exposure to some plant growth regulators –pyridine N-oxide methyl derivatives. Materials and Methods. For the aim of this research we used PGR 2.6-dimethyl- pyridine N-oxide (Ivin) and a complex of 2.6- dimethylpyridine-N-oxide with succinic acid (Poteitin). PGR in the form of an aqueous solution was administered to male Wistar Han rats orally with a probe: Ivin at doses of 650 mg/kg (1/2 LD50) and 13 mg/kg (1/100 LD50), Poteitin – at doses of 1150 mg/kg (1/2 LD50) and 23 mg/kg (1/100 LD50). The influence of Ivin and Poteitin on the lipid peroxidation (LPO) and the antioxidant system under a single oral exposure to the body of male rats was determined on days 1, 3, and 7. LPO in liver tissues was determined by the content of malondialdehyde (MDA), diene conjugates (DC), ketodienes (KD), conjugated trienes (CT) and Schiff bases (SB). MDA level was determined by the reaction with 2-thiobarbituric acid, DC, KD, CT, and SB in liver tissues – by the extraction-spectrophotometric method. The antioxidant status of the body was assessed by the activity of the catalase enzymes (CAT), glutathione peroxidase (GP), glutathione reductase (GR), the content of reduced glutathione (GSH) and total antioxidant activity (AOA). The results of the research were estimated by standard methods of variational statistics according to Student’s t-test criterion. Results. It was established that Ivin in the researched doses in the heptane fraction reduces the LPO intensity (containing MDA, DC, SB) in the liver tissues of rats, in the isopropanol fraction – DC; increases the activity of catalase and total AOA in blood serum. Poteitin in the tested doses in the heptane fraction reduces the formation of lipid products (containing MDA, DC, KD and CT) in the liver tissues of rats, in the isopropanol fraction – DC; increases the activity of catalase and the content of GSH, total AOA. Both substances do not disrupt the glutathione system. Compared to Ivin, Poteitin has a more pronounced effect on the intensity of LPO and the activity of the antioxidant system. Conclusions. 1. Plant growth regulators Ivin and Poteitin, at a single exposure to the body of male rats in doses corresponding to 1/2 and 1/100 LD50, reduce pro-oxidant activity, do not disrupt the glutathione system, increase the activity of the antioxidant system. 2. Increase in the activity of the antioxidant system and inhibition of the intensity of lipid peroxidation processes both under the influence of Ivin and Poteitin are aimed at adapting the body to the chemical factor. 3. Activation of the antioxidant system together with a decrease in the intensity of LPO can be one of the mechanisms of protection of the body from the toxic effects of pesticides when they are simultaneously introduced into the body with plant growth regulators based on methyl derivatives of pyridine N-oxide. Key words: plant growth regulators, Ivin, Poteitin, prooxidant and antioxidant systems.