Avaliação do uso do imunomodulador β (1-3) glucana isoladamente e em associação ao Itraconazol na esporotricose experimental

Abstract

The sporotrichosis, subcutaneous mycosis caused by the fungus dimorphic Sporothrix schenckii, can infect the man and several species of animals. The domestic felines are involved in the zoonotic reports of this illness. Considering the therapeutic difficulties in the treatment of this mycosis in felines, including toxicity and the resistance development to the antifungal currently use, the aim of the study was evaluate the effectiveness of the immunemodulator β (1-3) glucan isolate and in association with itraconazole in the treatment of the experimental cutaneous sporotrichosis. One hundred mice Wistar, strain UFPel, males were used. They were divided in four groups with 25 animals: group control (G1) witch received 0,5ml of sterile distilled water orally (VO) and 0,25ml of sterile saline solution subcutaneously (SC); group G2 treated with 10mg/kg of itraconazole VO and 0,25ml of saline solution SC; group G3 treated with 10mg/kg of itraconazole VO associated to 0,5 mg of β (1-3) glucan SC and the group G4 treated with 0,5 ml of distilled sterile water VO and 0,5 mg β (1-3) glucan SC. Animals were inoculated subcutaneously with 2x103 cells of Sporothrix schenckii/ml, and after 12 days, when all of them had already show characteristic lesions of sporotrichosis, the treatment was started, continuing for six weeks. Antifungal and distilled sterile water were administered daily, while the saline solution and the β (1-3) glucan weekly. Ten randomized animals of each group were choused and submitted to clinical evaluations weekly observing the presence of nodules, ulcers, regression and cicatrisation of the lesions during the experimental period. The remaining animals (three of each group) were weekly necropsied for the quantification of the units forming fungal colonies (UFCs), retroisolation and for histopathology evaluation. The same procedure was accomplished in the animals submitted to the evaluations at the end of the treatment. In clinical evaluation statistical difference was observed (p <0,05) among the groups G2, G3 and G4 in relation to the control (G1). Among the treated groups, the group G3 resulted in larger frequency (9/10) of animals with regression process and cicatrisation of the lesions. In UFCs as well as in the retro isolation of the S. schenckii statistical differences were observed between the treated groups and control. The group G3 demonstrated the smallest fungal quantification as well as the minimum positive retro isolation of the agent. In the histopathology evaluation the presence of initial 10 granulomas was verified as well as the late ones. In the G1 the prevalence was for initial granulomas. Similar inflammatory infiltrated was observed in all experimental groups, however G3 and G4 showed larger frequency (32%, 36%) of animals with polymorphonuclear infiltrate. According to the observed results, we conclude that all of the treatments were effective against cutaneous experimental sporotrichosis, however the glucana and itraconazole association showed an earlier lesions decreases.