Administration of Dehydroepiandrosterone (DHEA) as a mediator of the immune response in young and aged Wistar rats infected with Trypanosoma cruzi and submitted to repetitive stress

• Grant number: 06/02619-4
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2007
• End date: April 30, 2009
• Field of knowledge: Biological Sciences - Parasitology - Protozoology of Parasites
• Principal Investigator: José Clóvis do Prado Júnior
• Grantee: José Clóvis do Prado Júnior
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Chagas' disease (South American trypanosomiasis) affects up to 18 million people in Latin America and is caused by the blood-borne protozoan Trypanosoma cruzi. The specific treatment of Chagas' disease is based on the use of two drugs, benznidazole and nifurtimox. The nitroderivative benznidazole is the only available drug used to reduce parasitism, eliminate the acute-phase symptoms, and abbreviate the course of infection. Despite its use, benznidazole is highly toxic and has limited efficacy, especially in the chronic phase of the disease. Recently it has been described that repetitive stress worsens the acute phase of the infection. another paper (in press) it was demonstrated that plasmatic elevation of corticosterone (CT) seems to be involved in this response.Several negative effects due to CT elevation were described in different species, including the suppression of the immune response and neuronal death among others.During senescence enhanced levels of CT take place and a reduction of Dehydroepiandrosterone (DHEA).CT has a strong immunesupressor activity, while DHEA acts in an opposite way enhancing immunity and with an anti-stress effect.This work has as objectives to evaluate the immune enhancer capacity of DHEA when administered to young and aged Wistar male rats infected with the Y strain of Trypanosoma cruzi, treated before and after repetitive stress. Through the analysis of immunological and pathological parameters, there open a possibility of using this substance as an alternative therapy in triggering conditions to the host to direct a better immune response, as well as to minimize the negative effects of the stress and aging at the same time. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CAETANO, LEONY CRISTINA; BRAZAO, VANIA; FILIPIN, MARINA DEL VECCHIO; SANTELLO, FABRICIA HELENA; CAETANO, LUANA NAIARA; ALONSO TOLDO, MIRIAM PAULA; CALDEIRA, JERRI C.; DO PRADO JUNIOR, JOSE CLOVIS. Effects of repetitive stress during the acute phase of Trypanosoma cruzi infection on chronic Chagas' disease in rats. STRESS-THE INTERNATIONAL JOURNAL ON THE BIOLOGY OF STRESS, v. 12, n. 2, p. 144-151, 2009. (06/02619-4)

CAETANO, LEONY CRISTINA; BRAZAO, VANIA; FILIPIN, MARINA DEL VECCHIO; SANTELLO, FABRICIA HELENA; ALONSO TOLDO, MIRIAN PAULA; CALDEIRA, JERRI C.; DO PRADO JUNIOR, JOSE CLOVIS. Corticosterone evaluation in Wistar rats infected with the Y strain of Trypanosoma cruzi during the chronic phase. Experimental Parasitology, v. 127, n. 1, p. 31-35, JAN 2011. (06/02619-4)