EFFECT OF LOW INTENSITY LASER THERAPY (WAVELENGTH 1265 NM) ON THE LEVEL OF ACTIVE OXYGEN AND LIPID PEROXIDATION-ANTIOXIDANT SYSTEM IN CHO-K1 AND A875 CELLS
Near-infrared laser therapy has a significantly greater ability to penetrate living tissues compared to visible range optical radiation and often has the opposite effect on normal and malignant cells, thus being a promising tool for superficial neoplasm therapy. However, the mechanisms underlying the interaction between laser and biological structures can be of a different nature due to the chosen wavelength, power, and other radiation parameters. The aim of the paper is to study the efficacy of laser radiation with a wavelength of 1265 nm (9.45-18.9 J/cm<sup>2</sup>) on the generation of reactive oxygen species (ROS), the enzyme level of the antioxidant defence (AOD) and lipid peroxidation (LPO) in normal and cancer cells of Chinese hamster ovary epithelial cell line CHO-K1 and human melanoma A875. Materials and Methods. The experiment was carried out on cell lines CHO-K1 and A875, which were submitted to laser irradiation (wavelength 1265 nm, power 4.2-100 mW) for 30-60 min. Fluorescent staining with DCFH-DA was used to study intracellular ROS concentration; ImageJ software was used for image processing. The level of LPO products and the activity of AOD enzymes were determined by biochemical methods. Statistical processing of the results was carried out using the Mann-Whitney U-test (p<0.05). Results. The authors revealed an increase in ROS level, a decrease in superoxide dismutase and catalase activity, and a decrease in malondialdehyde level in CHO-K1 cells. An increase in catalase activity and malondialdehyde level was observed in A875 cells. Conclusion. Laser therapy (wavelength 1265 nm) enhances ROS generation and suppresses LPO-AOD system in the noncancerous cell line CHO-K1. However, opposite irradiation effects are observed in melanoma A875 cells.