Effect of hydroxyurea on the intracellular multiplication of Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi.

E.J.T Melo,H.J Beiral

doi:10.1590/s0100-879x2003000100009

E.J.T Melo, H.J Beiral

Open Access

https://doi.org/10.1590/s0100-879x2003000100009

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Abstract

Toxoplasma gondii, Leishmania amazonensis and Trypanosoma cruzi are obligate intracellular parasites that multiply until lysis of host cells. The present study was undertaken to evaluate the effect of hydroxyurea (an inhibitor of cell division at the G1/S phase) on the multiplication of L. amazonensis, T. gondii, and T. cruzi in infected host cells. Infected cells were treated with hydroxyurea (4 mM) for 48 h. Hydroxyurea arrested intracellular multiplication of all infective forms of the parasites tested. In treated cultures, the percent of infected host cells decreased (50-97%) and most intracellular parasites were eliminated. Ultrastructural observations showed no morphologic change in host cells while intracellular parasites presented drastic morphologic alterations or disruption. The results strongly suggest that hydroxyurea was able to interfere with the multiplication of intracellular parasites, leading to an irreversible morphological effect on L. amazonensis, T. gondii, and T. cruzi without affecting the host cells.

Highlights

Mean number of presence of medium 199 supplemented with 5% fetal calf serum (FCS) [11,13]
These results clearly show that the presence of hydroxyurea reduced both the percentage of infected cells and the number of intracellular parasites
Light microscopy demonstrated that treated Vero cells infected with T. gondii showed normal morphology, intracellular parasites, when present, were disrupted, in agreement with earlier observations [11]

Summary

Introduction

Mean number of presence of medium 199 supplemented with 5% FCS [11,13]. All parasites were assumed to have interacted with the cells because the parasite:host cell relationship was 10:1. The cultures in flasks were infected with parasites and incubated with the drug as described above for transmission electron microscopy. When infected cells were incubated with 4 mM hydroxyurea for 48 h, the number of infected cells decreased significantly in all treated cultures (Figure 1A, open columns) when compared with untreated control cells (Figure 1A, filled columns).

Results

Conclusion