Quantitave and qualitative interferences of pentoxifillyne on hepatic Schistosoma mansoni granulomas: Effects on extracellular matrix and eosinophil population

Mast cells and eosinophils actively participate in tissue repair and are pr ominent components of Schistosoma mansoni granulomas. Since pentoxifillyne (PTA) is an immunomodulatory and antifibrotic substance, we aimed to charac terize, by morphological techniques, the effect of this drug on fibrosis de veloped inside murine hepatic schistosomal granulomatous reaction, beyond t he quantification of eosinophil and mast cell populations. The drug (1 mg/1 00 g animal weight) was administrated from 35 to 90 days post-infection, wh en the animals were killed. The intragranulomatous interstitial collagen ne twork was analyzed by confocal laser scanning microscopy, the number of eos inophils and mast cells was quantified and the results were validated by t- student test. Treatment did not interfere on the granuloma evolution but ca used a significant decrease in the total and involutive number of hepatic g ranulomas (p = 0.01 and 0.001, respectivelly), and in the intragranulomatou s accumulation of eosinophils (p = 0.0001). Otherwise, the number of mast c ells was not significantly altered (p = 0.9); however, it was positively co rrelated with the number of granulomatous structures (r = 0.955). In conclu sion, PTX does not affect development and collagen deposition in S. mansoni murine granuloma, but decreases the intragranulomatous eosinophil accumula tion possibly due to its immunomodulatory capability, interfering in cellul ar recruitment and/or differentiation.