One of the most important compounds that exhibit a wide range of biological activities with especially strong antioxidant action are plant polyphenols. In the course of the experiment, the dose-dependent effects of polyphenols-rich extracts isolated from the Lamiaceae family Kazakhstani plants were studied on the processes of lipid peroxidation and on the degree of erythrocytes hemolysis. The activity of aqueous-ethanolic extracts from dried parts of plants, such as Origanum vulgare, Ziziphora bungeana, Dracocephalum integrifolium, Mentha piperita, Leonurus turkestanicus, Thymus serpyllum, and Salvia officinalis, was studied in a Wistar rat model. Lipid peroxidation (LPO) in liver microsomes was assessed by measuring malondialdehyde content in the form of thiobarbituric acid-reacting substances (TBARS). Estimation of osmotic resistance of isolated erythrocytes was evaluated based on hemoglobin absorbance. The amount of total phenolics in the extracts was measured using the Folin-Ciocalteu reagent method. Based on the results, Thymus serpyllum extract exhibited a significantly higher antioxidant activity (IC50 = 3.3 ± 0.7) compared to other plant extracts. Accordingly, among the extracts studied, those from Salvia officinalis, Thymus serpyllum, and Origanum vulgare show the most pronounced membrane-stabilizing activity. Antioxidant and antihemolytic properties of green tea and Origanum vulgare extract mixtures were similar to that of each individual plant extract. Similar results were obtained when the green tea extract was mixed with Mentha piperita, Ziziphora bungeana, and Dracocephalum integrifolium extracts, indicating no discernible synergistic interaction.
Keywords: antioxidants; flavonoids; lipid peroxidation; plant extracts; tea beverages.