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Purpose: Our goal was to analyze the outcome of infection and response to benznidazole (BZ) treatment in mice intragastrically inoculated with trypomastigotes forms of Trypanosoma cruzi from different origins., Methods: Twenty-four Swiss mice were divided in two groups and inoculated, by gavage, with 1 × 10 4 blood trypomastigotes (BT) or insect-derived metacyclic trypomastigotes (IT) of AM14 strain (T. cruzi IV). Half of the animals of each group were treated with BZ (TBZ), from 10 to 30th days after the inoculation, and the other constituted the untreated control groups (NT). After the etiological treatment, all mice were immunosuppressed with cyclophosphamide for three weeks. Parasitological and molecular parameters, infectivity, cumulative mortality, and reactivation post-immunosuppression rates were obtained., Results: Animals inoculated with BT showed lower pre-patent period and early day of the maximum parasitemia, as well as a higher maximum peak of parasitemia than the IT animals. However, both, BT and IT animals, did not respond to BZ treatment (0.0% of cure)., Conclusion: We conclude that the infective form influences in the outcome of infection, but not the response to the etiological treatment in mice intragastrically infected with the T. cruzi IV strain studied., (© 2021. Witold Stefański Institute of Parasitology, Polish Academy of Sciences.)

Background: Trypanosoma cruzi is the etiological agent of Chagas disease (CD) or American trypanosomiasis, an important public health problem in Latin America. Benznidazole (BZ), a drug available for its treatment, has limited efficacy and significant side effects. Essential oils (EOs) have demonstrated trypanocidal activity and may constitute a therapeutic alternative. Our aim was to evaluate the efficacy of the EOs of clove (CEO - Syzygium aromaticum) and ginger (GEO - Zingiber officinale), administered alone and in combination with BZ, in Swiss mice infected with T. cruzi., Methods: The animals were inoculated with 10,000 blood trypomastigotes of the Y strain of T. cruzi II by gavage and divided into four groups (n = 12 to 15): 1) untreated control (NT); 2) treated with BZ; 3) treated with CEO or GEO; and 4) treated with BZ + CEO or GEO. The treatments consisted of oral administration of 100 mg/kg/day, from the 5th day after parasite inoculation, for 20 consecutive days. All groups were submitted to fresh blood examination (FBE), blood culture (BC), conventional PCR (cPCR) and real-time PCR (qPCR), before and after immunosuppression with cyclophosphamide., Results: Clove and ginger EOs, administered alone and in combination with BZ, promoted suppression of parasitemia (p < 0.0001), except for the animals treated with CEO alone, which presented a parasitemia curve similar to NT animals. However, there was a decrease in the BC positivity rate (p < 0.05) and parasite load (< 0.0001) in this group. Treatment with GEO alone, on the other hand, besides promoting a decrease in the BC positivity rate (p < 0.05) and parasite load (p < 0.01), this EO also resulted in a decrease in mortality rate (p < 0.05) of treated mice., Conclusions: Decreased parasite load, as detected by qPCR, was observed in all treatment groups (BZ, CEO, GEO and BZ + EOs), demonstrating benefits even in the absence of parasitological cure, thus opening perspectives for further studies.

The effects of infection with Toxoplasma gondii vary from asymptomatic to the development of alterations in various organs (including the liver and kidneys) which may be irreversible, and lead to the death of the host. Whereas homeopathy is an alternative and effective method for treating various diseases, including those caused by protozoa, we questioned the effect of using Lycopodium clavatum in mice infected with T. gondii. One hundred male Swiss mice, 60 days old, were divided into four groups (n = 25/group): NIC (uninfected and untreated control), IC (infected and treated with un-dynamized 7% alcohol solution [vehicle]), G48 (infected and treated 48 h before infection and treated three more times; at 2, 4, and 6 days post-infection (dpi) with L. clavatum 200dH), and G72 (infected and treated for 3 consecutive days before infection with L. clavatum 200dH). In this study, physiological, histopathological, and immunological parameters were evaluated. The L. clavatum 200dH intensified renal damage in mice infected with T. gondii from 7 dpi, causing severe and progressive alterations during this period, such as various degrees of inflammation, edema, atrophy, and tubular cystic dilation, degenerated tubules with intra-cytoplasmic vacuoles and coalescing spots, severe vascular lesions, glomerulonephritis, and peri-glomerular congestion. In the G72 animals, which received L. clavatum 200dH, more severe cortex damage was observed (91.66-96.66%) as compared to the IC group (55-80%) and more renal corpuscle, and renal tubule injury was observed (80 ± 5 to 96.7% ± 2.89 of the total area) during all periods, as compared to the IC group (p < 0.05). Both groups presented high liver enzyme levels, and the highest values for AST were observable at 60 dpi. We observed significant increases of type I and III collagen, as well as high levels of TGF-β1 in both organs of the treated animals, the main factor involved in fibrosis in areas damaged by the process. L. clavatum 200dH intensifies kidney and liver alterations in mice infected with T. gondii. Our results reinforce caution when indicating administration schemes and dosages for ultra-diluted drugs.

Chagas disease (CD), caused by Trypanosoma cruzi, remains a serious public health problem. One of the causes of the high morbidity and mortality in patients is the lack of an effective drug therapy. Thus, the aim of this study was to evaluate the efficacy of the essential oil of Syzygium aromaticum alone and in combination with benznidazole (BZ) in mice orally inoculated with strain of T. cruzi IV obtained from oral CD outbreak occurred in Western Brazilian Amazonia. All the animals inoculated with metacyclic trypomastigote forms (AM14 strain, BZ resistant), derived from the insect Rhodnius robustus, became infected and there was no difference in the mortality rate between the experimental groups. When compared with untreated control animals (UTC), the treatment with essential oil of S. aromaticum (EOSA) alone promoted reduction in 1/5 parameters derived from the parasitemia curve, whereas the treatments with BZ alone or in combination (BZ + EOSA) promoted reduction in 4/5 of those parameters, presenting similar profiles of parasitemia curve. The animals treated with BZ and with the combination BZ + EOSA presented lower patency periods in comparison with the animals in EOSA group, and lower positivity of blood cultures when compared with the UTC group. The results of molecular analysis by qPCR in both blood and cardiac tissue did not show differences between the groups. The cure rates obtained with the different treatments presented the following ascending order: EOSA = 12.5% (1/8), BZ = 25.0% (2/8) and BZ + EOSA = 37.5% (3/8). Although there are no significant differences between them, these results claims that the use of this essential oil could be of interest for treatment of Chagas disease., (Copyright © 2018 Elsevier Inc. All rights reserved.)