Influence of age and ways of treatment in the parasitemia in mice infected with Trypanosoma cruzi treated with high potency biotherapy

Abstract

Introduction: The infection of mice by Trypanosoma cruzi is well known, making this a good model for understanding the effect of highly diluted medications. Mice of different ages show different responses to biotherapic T. cruzi [1]. Other data from our laboratory using biotherapic treatment at low potencies show that long lasting treatment has a better effect in mice infected with T. cruzi. However, the use of high potency biotherapics in mice of different ages infected with T. cruzi has not been analysed yet. Aim: To evaluate the effect of different ways of treatment using biotherapic 200 DH T. cruzi in the evolution of the curve of parasitemia of mice of different ages infected with T. cruzi. Materials and methods: A blind randomized controlled trial was performed using 107 swiss male mice, aged 28, 35 and 56 days, divided into groups: CONTROL(C) - mice aged 28(C28), 38(C38) and 56(C56) days, treated with 7% water-alcohol solution diluted with water (1mL/100mL); ONE DAY(OD) - mice aged 28(OD28), 38(OD38) and 56(OD56) days, treated with highly diluted medication 200 DH T. cruzi in a single dose, diluted in water (10mL/100mL); EVERY DAY(ED) - mice aged 28(ED28), 38(ED38) and 56(ED56) days, treated with highly diluted medication 200DH T.cruzi until the end of the experiment, diluted in water(1mL/100mL). Amber bottle was used and the water was changed every two days. The groups were infected with strain Y-T. cruzi, intraperitoneal,1400 blood trypomastigotes. Medicines were handled according to the Brazilian Homeopathic Pharmacopoeia [2], with microbiological testing according to RDC n° 67 and in vivo biological risk. We compared the parasitemia curve and total parasitemia, determined daily counting of the parasites [3], obtained using the tests Kruskal-Wallis and Wald-Wolfowitz, Statistica 8.0, 5% significance. Approved by the Ethics Committee for Animal Experimentation/ UEM - 030/2008. Results: The animal age and the ways of treatment used influenced the evolution of the parasitemia curve. This evolution was different among different ages, and the youngest mice of the control group had higher averages of parasitemia ( C28=1.4x106/mL; C38= 1.3 x106/mL and C56=1.0x106/mL ) (fig1). This evolution was not observed in the groups treated daily, in which 56 day-old mice presented a higher parasitemia compared to the other groups ( ED28= 1.3x106/mL; ED38=0.9x106/mL and ED56=1.2x106/mL )(fig1b). For animals treated with a single dose, the energetic stimulus provided by biotherapic caused homogeneity of biological behavior, with significant elevation of parasitemia ( OD28=1.8x106/mL; OD38=1.3x106/mL and OD56=1.5 x106/mL) (fig1c). Likewise, the single dose treatment invariably resulted in an increase of parasitemia when compared to other treatments within the same age group (fig1d-f). The treatment performed daily in animals aged 28 and 38 days showed a decrease in parasitemia (fig1d-f). For 56 day-old mice this fall was not observed (fig1f). The meaning of this finding should be better explored considering the physiological maturity versus the vital energy of mice of different ages. Conclusion: The age and the ways of treatment used are important factors to be considered when using a highly diluted medication. The clinical use of these results in humans, should take into consideration the allometric system of medication dosage which takes into account the metabolic rate of each organism.