Effects of the phototherapy (blue light) on the heart inflammatory response induced by Trypanosoma cruzi in mice.

Abstract

The Trypanosoma cruz, is the causative agent of Chagas disease. According to WHO (2019), currently about 7 million people are infected with T. cruzi mainly in Latin America. Despite the fact that pharmaceutical industry releases various new drugs every year, Chagas disease has only two standard substances for treatment, Benznidazole and Nifurtimox, which were recognized as chemotherapy. However, at the same time these medicines have many side effects and are inefficient in chronic phase. Nowadays the blue light is commonly used in medicine practice around the world. It was proved its antimicrobial characteristics. In the current study, were evaluated the influence of the blue light on the inflammatory parameters in C57BL6 mice (in vivo) infected with T. cruzi and as well as development of parasites in vitro. For in vitro experiment we used Y and CL strain of T. cruzi. The blue light was applied (with the pic 460 nm and 80 μW/cm2) on parasite cell culture for 5 days, 6h per day, at room temperature. The parasites were counted in 10 μL every day using the Neubauer Chamber. Treatment with the blue light led to the reduction of replication of T. cruzi in vitro. Data showed 50% reduction of parasites in experiment after 5 days of exposition, in comparison to control. For in vivo experiment was used Y strain of T. cruzi. 40 animals were separated into 4 groups: non-infected + conventional light, non-infected + blue light, infected + conventional light, and infected + blue light. Blue light was applied (with the pic 460 nm and 7 μW/cm2) for 9 days, 12 h per day. Was found that phototherapy with blue light reduce quantity of parasites circulating in the blood of animals comparing with conventional light. Blue light altered the plasma pattern of the inflammatory and regulatory mediators. After morphological analysis, was found that both infected groups exhibited parasitized cardiomyocytes with intense myocarditis with predominance of pericellular and perivascular mononuclear inflammatory infiltrate. Phototherapy with blue light reduced the quantity amastigote in the nests in cardiac tissue. These data can be used for the development of a new way of treatment for Chagas disease in the future.