Features of meldonium effect on the cells viability and mitochondria of blood leucocytes in patients with angina pectoris

Background. The ambiguous effectiveness of cardiocytoprotectors and the low level of evidence for their use in coronary heart disease (CHD) necessitate the study of their direct effect on cell viability for assessing cytoprotective activity. The aim. To determine the specific effects of meldonium on the cells viability and mitochondria of blood leukocytes in patients with angina pectoris. Materials and methods. Thirty-one patients with stable angina were examined. The lipid profile; antioxidant protection; and respiratory control of blood plasma were determined using biochemical methods. The viability of blood leukocytes and the fluorescence intensity of their mitochondria were studied using fluorescence microscopy. Meldonium was tested in vitro. Statistical data processing was performed. Results. Two variants of changes in cell viability under the influence of meldonium were found: in the form of an increase or decrease in this indicator. An increase in cell viability occurred due to an increase in the number of living cells in patients with normal values of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C); provided that the activity of antioxidant cell protection enzymes (catalase; superoxide dismutase) was maintained; with the prevalence of anabolism processes. A decrease in cell viability under the influence of meldonium occurred due to an increase in the number of dead cells in patients with elevated values of total cholesterol and LDL-C; provided that the enzymatic activity of the antioxidant system was depleted and catabolism processes prevailed. The value of mitochondrial fluorescence of blood leukocytes in both cases changed towards an increase; but in the first case only by 3 %; and in the second – by 6 %. Conclusion. According to in vitro studies; meldonium can have a dual effect on cell viability – either increasing or decreasing it by increasing the number of living or dead cells. The resulting effect of meldonium depends on the individual metabolic characteristics of a particular patient; the state of their energy metabolism and antioxidant protection of cells.