RESUMEN
Toxoplasmosis is a tropical and neglected disease caused by the parasitic protozoa Toxplasma gondii. Conventional treatment with sulfadiazine and pyrimethamine plus folinic acid, has some drawbacks, such as inefficacy in the chronic phase, toxic side effects, and potential cases of resistance have been observed. In this study, the activity of essential oils (EOs) from three Piper species and their main constituents, including α-Pinene (Piper lindbergii and P. cernuum), ß-Pinene (P. cernuum), and dillapiole (P. aduncum), were evaluated against tachyzoites of T. gondii. α-Pinene was more active [(IC50 0.3265 (0.2958 to 0.3604) µg/mL)] against tachyzoites than P. lindbergii EO [0.8387 (0.6492 to 1.084) µg/mL]. Both α-Pinene and P. lindbergii EO exhibited low cytotoxicity against NHDF cells, with CC50 41.37 (37.64 to 45.09) µg/mL and 83.80 (75.42 to 91.34) µg/mL, respectively, suggesting they could be of potential use against toxoplasmosis.
RESUMEN
There is a lack of studies using Toxoplasma gondii strains isolated from human patients. Here, we present a pathological study of three strains obtained from human cases of congenital toxoplasmosis in Brazil using inbred mice after oral infection with 10 tissue cysts. Multiplex-nested PCR-RFLP of eleven loci revealed atypical genotypes commonly found in Brazil: toxodb #8 for TgCTBr5 and TgCTBr16 strains and toxodb #11 for the TgCTBr9 strain. BALB/c and C57BL/6 mice were evaluated for survival and histological changes during the acute phase of the disease. All mice inoculated with the non-virulent TgCTBR5 strain survived after 30 days, although irreversible tissue damage was found. In contrast, no mice were resistant to infection with the highly virulent TgCTBR9 strain. The TgCTBr16 strain resulted in 80% survival in mice. However, this strain presented low infectivity, especially by the oral route of infection. Despite being identified with the same genotype, TgCTBr5 and TgCTBr16 strains showed biological differences. Histopathologic analysis revealed liver and lungs to be the most affected organs, and the pattern of tissue injury was similar to that found in mice inoculated perorally with strains belonging to clonal genotypes. However, there was a variation in the intensity of ileum lesions according to T. gondii strain and mouse lineage. C57BL/6 mice showed higher susceptibility than BALB/c for histological lesions. Taken together, these results revealed that the pathogenesis of T. gondii strains belonging to atypical genotypes can induce similar tissue damage to those from clonal genotypes, although intrinsic aspects of the strains seem critical to the induction of ileitis in the infected host.