Action of pentoxifylline on experimental cutaneous leishmaniasis due to Leishmania (Leishmania) amazonensis

In the animal model of leishmaniasis caused by Leishmania (Leishmania) amaz onensis there is a complex mechanism of the host-parasite interaction. The present study was performed to interfere with the inflammatory reaction to the parasites, through immune modulation. Female C5BL/6 isogenic mice were used, some of which were inoculated on the right ear and others on the righ t footpad with 3.10(6) stationary phase promastigotes of the MHOM/BR/PH8 st rain of L. (L.) amazonensis, and were allocated in three groups: the first received pentoxifylline 8mg/kg every 12 h, since the first day; the second orae received the same nose since the 40th day of infection and a control g roup that did not receive any treatment. All the ears excised were analyzed to determine the variation in weight between both ears and for histopathol ogical analyses. A quantification of the parasites was done using the limit ing dilution assay. A significant reduction of the number of parasites, was observed among the animals treated which had an accordingly significant re duction on the weight of the ears. Pentoxifylline reduced the macrophages p ropensity to vacuolation and induced a more effective destruction of the pa rasites by these cells. Moreover; the group that began the treatment later did not show the same effectiveness.