The study of the antioxidant activity of polyphenol extracts from cranberry leaves on the model of insulin resistance

Abstract

Topicality. In Ukraine, the number of patients with diabetes is growing rapidly, it ranks the 4th in the structure of diseases of the endocrine system, and it is one of the main causes of incapacitation and disability among the population and takes the second place by the number of deaths. Polyphenolic extracts from leaves of the heather (Ericaceae) family, in particular blueberries, cranberries and bearberry, in the previous studies demonstrated the presence of antioxidant, hypoglycemic and lipotropic properties. However, the pharmacological activity of extracts from cranberry leaves has not been sufficiently studied. Aim. To study the effect of polyphenolic extracts from cranberry leaves on the processes of LPO and the state of the antioxidant defense in the liver and serum in rats with the experimental insulin resistance. Materials and methods. The study was performed on white outbred male rats weighing 180 ± 15 g, kept in the vivarium of the NUPh. Insulin resistance was induced by keeping animals on a high fructose diet for 6 weeks according to the recommendations. The extracts were administered intragastrically in the dose of 200 μg/100 g of the body weight from the fourth week of the experiment for 14 days. The POL activity was assessed by the level of TBA reactants, diene conjugates and conjugated trienes in the liver and serum. The state of the antioxidant defense was assessed by the level of reduced glutathione, as well as the activity of catalase and superoxide dismutase. Indicators were determined by the spectrophotometric method. Results and discussion. The development of the experimental resistance was accompanied by an increase in LPS activity in the liver and serum of rats. In the serum of animals with IR the content of primary products of LPO increased in 1.75 times, the content of triene conjugates in 1.7 times, respectively, while the content of TBA reactants in 1.61 times. The introduction of the polyphenolic concentrate from cranberry leaves was accompanied by a sharp decrease in the products of lipid peroxidation both in the eserum and liver to almost ascending levels. There was normalization of the activity of enzymes of the first line of the antioxidant defense compared to animals with insulin resistance due to the presence of plant flavonoids in the extract. Conclusions. Thus, the data obtained indicate that the polyphenolic extract from cranberry leaves exhibits antioxidant properties in the liver and serum of rats with the experimental insulin resistance. The polyphenolic extract also restored the antioxidant defense of cells and the body as a whole. The data obtained indicate the need for further research to create a new herbal medicine for use in the treatment of insulin resistance and diabetes.