THE IMPORTANCE OF A PHOTOSENSITIZER BLEACHING REGISTRATION FOR THE EVALUATION OF MECHANISM OF PREPARATION ACTION ON THE PHOTO-INDUCED HEMOLYSIS

The influence of three pharmaceutical preparations on photo-induced lysis (irradiation with light-emitting diode of 653 nm) of human erythrocytes in the presence of photosensitizer radachlorin and also on the quantum yield of radachlorin photobleaching was studied. Both processes are mediated by singlet oxygen generation and therefore can become a target for antioxidant or prooxidant regulation. The pyridine preparation mexidol (action principle – 3-hydroxy-6-methyl-2-ethylpyridine succinate) in concentration of 152 µM used as an antioxidant and a membrane protector and aminazine (action principle – chlorpromazine) in concentration of 70 µM many times accelerated manyfold the photo-induced hemolysis. However only mexidol increased the quantum yield of radachlorin photobleaching in many times. The obtained data showed the direct prooxidant action of mexidol, but not aminazine that accelerated a photo-induced hemolysis due to other mechanism. A pyridine preparation nicotinic acid tested in equimolar to mexidol concentration, failed to influence both the velocity of the photo-induced hemolysis and the quantum yield of radachlorin photobleaching. Our study shows the possible use of a photobleaching tests for detection of the direct prooxidant action.