ABSTRACT
The aim of this study was to evaluate the effects of a treatment using injectable zinc and copper in rats infected with Trypanosoma evansi. 48 rats were divided into eight groups of six animals each. Group A was composed of uninfected animals. Animals from groups B-H were inoculated at the 5th day of experiment with 1.2×10(6) trypanosomes. Group B was used as a positive control. The infected groups received prophylactic (C, D and E) and therapeutic (F, G and H) treatments with the zinc and copper, both at a dose of 5 mg kg(-1). The effectiveness of treatment was confirmed by negative blood smears and Polymerase Chain Reaction (PCR) at the end of study. All treated animals had their prepatent period and survival prolonged when compared with control group (group B). Treatment efficacy was 17% (C: zinc), 33% (D: copper), 50% (E: zinc+copper), 0% (F: zinc), 50% (G: copper) and 50% (H: zinc+copper). Thus, we can conclude that treatment with zinc and copper are capable of controlling and/or curing T. evansi infection in rats, delaying the parasitemia and prolonging their survival.
Subject(s)
Copper/therapeutic use , Trypanosoma/drug effects , Trypanosomiasis/drug therapy , Zinc/therapeutic use , Animals , Brain/parasitology , Copper/pharmacology , DNA, Protozoan/isolation & purification , Dose-Response Relationship, Drug , Female , Parasitemia/drug therapy , Rats , Trypanosoma/genetics , Trypanosoma/isolation & purification , Zinc/pharmacologyABSTRACT
Current therapy of Trypanosoma evansi infections is not effective for the vast majority of animals with relapsing parasitemia and clinical signs. Recently, attention is being focused on the antiparasitic activity of propolis. This study evaluated the susceptibility of T. evansi to propolis extract in vitro and in vivo. A dose-dependent trypanocidal activity of propolis extract was observed in vitro. All trypomastigotes were killed 1 h after incubation with 10 µg mL(-1) of the extract. In vivo, the concentrations of 100, 200, 300 and 400 mg kg(-1) administered orally for 10 consecutive days showed no curative effect, and the rats died from the disease. However, rats treated with the two highest concentrations of propolis extract showed higher longevity than the other groups. Based on these data, we concluded that T. evansi is susceptible to propolis in vitro. Despite the lack of curative efficacy observed in vivo at the concentrations tested, the propolis extract can prolong life in rats infected with the protozoan.
