Release of the cytosolic tryparedoxin peroxidase into the incubation medium and a different profile of cytosolic and mitochondrial peroxiredoxin expression in H2O2-treated Trypanosoma cruzi tissue culture-derived trypomastigotes.

Trypanosoma cruzi antioxidant enzymes are among the factors that guarantee parasite survival and maintain infection, enabling T. cruzi to cope with oxidative stress. Herein, the expression of cytosolic (TcCPx) and mitochondrial (TcMPx) tryparedoxin peroxidases was evaluated in tissue culture-derived trypomastigotes upon incubation with different concentrations of H(2)O(2). TcCPx expression slightly increased (5.4%) in cells submitted to 10 µM H(2)O(2) treatment when compared to the control, but decreased when higher H(2)O(2) concentrations (20-50 µM) were employed. Under these conditions, TcMPx expression increased (∼53%) with 10 µM-treatment compared to the control, followed by a reduction that reached ∼46% of the control when using the highest concentration tested. Interestingly, in the supernatant of the incubations, TcCPx, but not TcMPx, was detected, and its levels increased concomitantly with its decreased expression in the intracellular compartment. Our data show that peroxiredoxins in the tissue culture-derived trypomastigote can be modulated under oxidative stress and are present in higher amounts when compared to the epimastigote stage of T. cruzi. Additionally, due to the different expression patterns observed upon H(2)O(2)-treatment, each peroxiredoxin may play a distinct role in protecting the parasite under oxidative stress conditions.

Dynamics of reepithelialisation and penetration rate of a bee propolis formulation during cutaneous wounds healing.

The aim of this work is to investigate the dynamics of reepithelialisation and the penetration rate of a propolis ointment formulation during cutaneous wounds healing. The experiments were performed as a function of the treatment time in a well controlled group of rats. We observed that the propolis ointment influenced the healing process stimulating keratinocytes cell proliferation as compared to the control group. It was shown that the propagation of the bee propolis was dependent on the wound healing stages. In addition, the photoacoustic spectroscopy showed that the applied substances reached the deep wound region, highlighting once again the particular characteristic of this technique to evaluate the penetration rate of substances through the skin.