BackgroundThere is no published information about the use of different protocols to administer a highly diluted medication.Evaluate the effect of different protocols for treatment with biotherapic T. cruzi 17 dH (BIOTTc17dH) on clinical/parasitological evolution of mice infected with T. cruzi-Y strain.MethodsA blind, randomized controlled trial was performed twice, using 60 28-day-old male Swiss mice infected with T. cruzi-Y strain, in five treatment groups: CI - treated with a 7% ethanol-water solution, diluted in water (10 μL/mL) ad libitum; BIOTPI - treated with BIOTTc17dH in water (10 μL/mL) ad libitum during a period that started on the day of infection; BIOT4DI - treated with BIOTTc17dH in water (10 μL/mL) ad libitum beginning on the 4th day of infection; BIOT4-5–6 - treated with BIOTTc17dH by gavage (0.2 mL/ animal/day) on the 4th, 5th and 6th days after infection; BIOT7-8–9 - treated with BIOTTc17dH by gavage (0.2 mL/ animal/day) on the 7th, 8th and 9th days after infection. We evaluated: parasitemia; total parasitemia (Ptotal); maximum peak of parasites; prepatent period (PPP) - time from infection to detection of the parasite in blood; patent period (PP) - period when the parasitemia can be detected in blood; clinical aspects; and mortality.ResultsParasitological parameters in the BIOTPI and mainly in the BIOT4PI group showed better evolution of the infection compared to the control group (CI), with lower Ptotal, lower maximum peak of parasites, higher PPP, lower PP and longer survival times. These animals showed stable body temperature and higher weight gain and water consumption, with more animals having normal-appearing fur for longer periods. In contrast, groups BIOT4-5–6 and BIOT7-8–9 showed worse evolution of the infection compared to the control group, considering both parasitological and clinical parameters. The correlation analysis combined with the other data from this study indicated that the prepatent period is the best parameter to evaluate the effect of a medication in this model.ConclusionsThe BIOT4DI group showed the best clinical and parasitological evolution, with lower parasitemia and a trend toward lower mortality and a longer survival period. The prepatent period was the best parameter to evaluate the effect of a medication in this model.

Biotherapy 7dH given before infection (7 or 30 days) produces different effects suggesting modulation of the host's immune system. The effects range from reduced parasitemia to its effective increase. The use of biotherapy to treat T. cruzi infection including dose, potency and schedule deserves further investigation.

There is a difference of high diluted medication effect in four and eight-week-old mice. In the group of animals 8 weeks the immunomodulatory effect seems to have been higher. Hence, treatment with the medicine produced from T. cruzi modulates the inflammatory response with increased apoptosis and decreased serum levels of TGF-β.

Chagas disease, caused by the protozoan Trypanosoma cruzi, involves immunomediated processes. Canova (CA) is a homeopathic treatment indicated in the diseases in which the immune system is depressed. This study evaluated the Random Amplification of Polymorphic DNA (RAPD) profile of T. cruzi under the influence of CA and Benznidazole (BZ). Mice infected with the genetic lineage of T. cruzi II (Y strain) were divided into 4 groups: Infected animals treated with saline solution (control group); treated with CA; treated with BZ; treated with CA and BZ combined. Treatment was given at the 5th-25th days of infection (D5-25). The parasites were isolated by haemoculture in Liver Infusion Tryptose (LIT) medium: at D5 (before treatment), D13, 15 and 25 (during treatment) and D55 and 295 (after treatment). DNA was extracted from the mass of parasites. RAPD was done with the primers lambdagt11-F, M13F-40 and L15996, the amplified products were eletrophoresed through a 4% polyacrylamide gel. Data were analyzed by the coefficient of similarity using the DNA-POP program. 163 markers were identified, 5 of them monomorphic. CA did not act against the parasites when used alone. The RAPD profiles of parasites treated with BZ and CA+BZ were different from those in the control group and in the group treated with CA. The actions of the CA and BZ were different and the action of BZ was different from the action of CA+BZ. These data suggest that CA may interact with BZ. The differences in the RAPD profile of the Y strain of T. cruzi produced by BZ, CA+BZ and the natural course of the infection suggest selection/suppression of populations.

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