Evaluation of the trypanocidal effect of inhibitors of the Ergosterol synthesis associated to the anti-inflammatory properties of Melatonin in the Chronic Chagasic Cardiomyopathy

• Grant number: 13/18626-3
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2013
• End date: November 30, 2015
• Field of knowledge: Health Sciences - Pharmacy - Medicines Analysis and Control
• Principal Investigator: Sérgio de Albuquerque
• Grantee: Luiz Gustavo Rodrigues Oliveira
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Treatment strategies based on the association of antiparasitic and immunomodulatory drugs have been considered promising in research for the treatment of Chagas disease. According to recent studies, potent inhibitors of the ergosterol biosynthesis, Posaconazole and Ravuconazole have shown trypanocidal activity with low toxicity in vivo, being considered as alternative drugs in the treatment of this disease. The neurohormone Melatonin has a remarkable in vivo versatility of effects, such as anti-inflammatory activity, antioxidant and immunomodulatory being used as a therapeutic substance in various experimental conditions, including T. cruzi infection. In the present study, complementary to the investigation of the possible effects of ergosterol biosynthesis inhibitors, Melatonin will be added in the attempt to achieve the elimination of parasites and to resolve the cardiac inflammatory process. Some goals will be accomplished: 1 - standardization of animals that will develop chronic myocarditis 2 - treatment with the substances proposed 3 - monitoring of cardiac function and plasma concentrations of drugs after treatment 4 - Evaluation of immunologic parameters and 5 - analyzing the resolution of the disease through cure criteria proposed. With the aid of ECG examination, we will study the in vivo effects of these substances under chronic myocarditis induced by the Y strain of T. cruzi in male Wistar rats. After euthanasia, histopathology techniques will be used to assess cardiac inflammatory foci and immunofluorescence for detection of reactive oxygen species (ROS) and nitric oxide (NO). The plasma levels of the drugs tested will be quantified as well as their half-lives. Cardiac inflammatory cells (CD3 + CD4 + / CD3 + CD8 + / CD4 + CD25 + FoxP3 + Treg) will be characterized and quantified by flow cytometry. ELISA assays for detection and quantification of pro-inflammatory cytokines: (INF-gama and TNF-alfa) / modulatory: (TGF-beta, IL-10) and real time PCR for detection and quantification of parasite DNA in the blood and cardiac tissue will be used. The data obtained from these experimental treatments may increase the scientific literature in the context of therapies based on the combination of different substances against Chagas' disease.