Photobiomodulation therapy protects red blood cells against nitrative stress during streptozotocin-induced diabetes

Abstract

Background. According to the International Diabetes Federation Diabetes Atlas, 10th edition, diabetes is responsible for 6.7 million deaths in 2021. Diabetes mellitus is a group of metabolic disorders characterized by hyperglycemia secondary to either resistance to insulin, insufficient insulin secretion, or both. Oxidative and nitrative stress is a vital part of the complex mechanism by which diabetes and its complications develop. It is known that Photobiomodulation therapy accelerates diabetic wound healing, treats relegated inflammation, and increases oxygen availability for cells. Although some basic molecular mechanisms caused by photobiomodulation therapy in different cell types are already known, they have not been studied in erythrocytes and are different due to the absence of central organelles such as nucleus and mitochondria. The aim of the study was to investigate the effect of photobiomodulation therapy on the development of nitrative stress in blood plasma and erythrocytes of rats from different experimental groups. Materials and Methods. The study was performed on white outbred male rats weighing 130–180 g. The diabetes mellitus was induced by intraperitoneal injection of streptozotocin (60 mg/kg). Rats were exposed to photobiomodulation with light-emitting diodes at a wavelength of 630–660 nm daily for 10 days. The irradiation time was 5 minu­tes. The content of nitrite and nitrate anions, total NO synthase activity, as well as the activity of its endothelial and inducible isoforms in red blood cells of rats were determined spectrophotometrically. Results and Discussion. Under streptozotocin-induced diabetes mellitus, the content of nitrite and nitrate anions and NO synthase activity increased in the rats’ red blood cells, as well as in blood plasma. Moreover, we found an increase in inducible NO synthase activity and nitrate ion content in red blood cells of irradiated healthy rats. Also, there was an increase in nitrite and nitrate ion content after photobiomodulation therapy in the blood plasma of healthy animals. On the other hand, irradiation caused a decrease in NO synthase activity with a parallel reduction in both nitrite and nitrate anions content in erythrocytes and blood plasma of rats with experimental diabetes. Conclusion. Photobiomodulation therapy protects rats’ red blood cells from nitrative stress during streptozotocin-induced diabetes mellitus. Keywords: diabetes mellitus, photobiomodulation therapy, nitrative stress, red blood cells