Efeito do extrato aquoso das folhas da Annona crassiflora (Araticum) na proliferação de T. gondii em células RAW 264.7

Abstract

Annona crassiflora is a native species of the Brazilian Cerrado that produces the araticum fruit. This plant contains several bioactive compounds with biological activities, including pharmacological, well described in literature, for example, antimicrobial and antiparasitic actions. So, in this study, the aqueous extract from A. crassiflora leaves was used to research the effect of Annona crassiflora aqueous extract (EAAC) on Toxoplasma gondii parasite proliferation in macrophage lineage cells – like RAW 264.7. Initially, the possible cytotoxicity effect of EAAC was assessed by the MTT (methylthiazole tetrazolium) test using RAW 264.7 cells treated with different extract concentrations (0.487 to 1.000 μg / mL). Then we evaluate the effect of EAAC on the T. gondii proliferation, clone 2F1, in RAW 264.7 cells. After 18 hours of infection, cells were lysed and intracellular parasites were quantified by colorimetric reaction using the CPRG chromogen. The 2F1 clone expresses the β-galactosidase enzyme; it converts the yellow-orange CPRG substrate to galactose and the red chlorophenol chromophore, developing a dark red color in the medium. The color intensity, therefore, corresponds to the enzymatic activity of β-galactosidase and it is an indirect measure to the quantitative determination of the number of parasites. The obtained results showed that EAAC were not cytotoxic to RAW 264.7 cells; EAAC did not reduced parasite proliferation in RAW 264.7 cells in a statistically significant way, although highier concentrations, 500 and 1000 μg / mL, there was a tendency for this reduction.