THE CORRECTIVE EFFECT OF PEPTIDES ON THE PRO- AND ANTIOXIDANT SYSTEM INDICATORS' CHANGES IN RATS OF DIFFERENT AGES AFFECTED BY HEAVY METALS AND GLYPHOSATE

Abstract

Introduction. It is known that the effects of various environmental pollutants, such as heavy metals and organophosphorus compounds, cause various changes in the human body, accompanied by imbalances between oxidation and reduction, the formation of reactive oxygen species, which explains the development of oxidative stress. Heavy metals and organophosphorus compounds used in agriculture cause diseases of the liver and other organs, which contributes to the formation of reactive oxygen species (ROS), which can induce lipid peroxidation and inhibit the antioxidant system. The basis of the action of heavy metals is the blocking of functionally active groups of structural proteins, enzyme proteins, the blocking of sulfhydryl (thiol, SH) groups is of greatest importance. Under the action of heavy metals, most proteins lose their physicochemical and biological properties, which leads to disruption of protein and other metabolism. To date, the correction of violations of free radical and antioxidant processes by the combined action of heavy metals and organophosphorus pesticides remains incompletely studied.

The aim of the study – to study the antioxidant activity (AOA) of the peptides in virto and iv vivo in rats of various ages affected by lead acetate, cuprum sulfate, and glyphosate (in the form of roundup herbicide).

Research Methods. Experiments were conducted on laboratory non-linear white male rats of three age groups (sexually immature, sexually mature and old), which were administered intragastrically for 30 days with aqueous solutions of lead acetate, copper sulfate and glyphosate. For the purpose of correction, on the 21^st day, 6 hours after the introduction of toxicants, peptides were administered for 10 days. Glutathione peroxidase, glutathione reductase, catalase, superoxide dismutase activity and the content of SH-groups, ROS, TBA-active products (TBA-AP) and diene conjugates (DC) were determined spectrophotometrically in blood serum and liver homogenate of affected and treated animals.

Results and Discussion. Heavy metals and organophosphorus compounds caused the formation of ROS, such as superoxide ions, hydrogen peroxide and hydroxyl radicals. With the combined action of lead acetate, copper sulfate, and glyphosate, the processes of free radical oxidation of lipids and the generation of ROS in rats were activated with age, which was evidenced by the increase in the content of DC, TBA-AP, superoxide anion radical, and hydroxyl radical. As our studies showed, the introduction of toxicants led to a decrease in glutathione peroxidase, glutathione reductase, catalase, superoxide dismutase activity, the level of SH-groups in blood serum and liver homogenate of affected animals. The use of peptides as correction factors contributed to a decrease towards the norm in the content of ROS and products of lipid peroxidation and normalization of the activity of enzymes of the antioxidant system, which obviously indicates the antioxidant and chelating properties of peptides.

Conclusion. Exposure of rats to lead acetate, copper sulfate and glyphosate at a dose of 1/20 LD50 leads to an increase in the content of TBA-AP, DC, ROS and a decrease in the activity of enzymes of the antioxidant system in blood serum and liver homogenate. Administration of peptides as corrective factors to animals of various ages with toxic liver damage increases glutathione peroxidase, glutathione reductase, catalase, and superoxide dismutase activity toward normal levels and reduces the content of lipid free radical oxidation products and ROS.