Abordagens terapêuticas na mucosite oral experimental induzida por 5-Fluorouracil : papel dos extratos de Aloe barbadensis (Babosa) e de Myracrodruon urundeuva (Aroeira do sertão)

Abstract

Oral mucositis (OM) is a frequent dose-limiting and costly complication of antineoplastic chemotherapy. It’s caractherized by ulcerative lesions and causes pain, restrict food and fluids oral intake and causes substancial risk for sepsis. In severe cases, hospitalization, parenteral nutrition and opiode analgesics are required. OBJECTIVES: Evaluate the effects of extracts of two herbal medicines, Aloe barbadensis Miller (Ab) and Myracrodruon urundeuva Allemão (Mu) on 5-fluorouracil-induced OM in hamsters. To evaluate the possible mechanisms by the extracts act, it was performed analysis of intensity of activity of myeloperoxidase (MPO) and analysis of immunohistochemistry for TNF-alpha and iNOS in mucosa specimens. METHODS: Golden siriam hamsters were submitted to intra-peritoneal 60 and 40 mg/Kg injections of 5-fluorouracil (5-FU) in day 1 and 2, respectively. On day 4, animals were submitted to anaesthesia, followed by mecanic trauma with needle to potenciate the effect of 5-FU. After that, the mucosas were treated with topical gel containing Mu extracts at 5, 10 or 20%, Ab extracts at 25, 50 or 100% (experimental groups) or carbapol gel (control group). The treatments above were mantained twice daily until day 9. On day 10 the animals were sacrified. Diferent parameters were evaluated: macroscopic and microscopic scores of OM, body mass variation and immunohistochemistry for TNF-alpha e iNOS. RESULTS: Mu significantly inhibited macroscopic oral mucositis at 5 and 10% concentrations (5% Mu – Md 2; 10% Mu – Md 3; control – Md 4, p < 0,01). Ab also inhibited OM (25% Ab – Md 1; 50% Ab – Md 1,5; 100% Ab – Md 1; control – Md 4, p < 0,001). These results were confirmed by histological analysis (5% Mu – Md 1,5; 10% Mu – Md 1; 25% Ab – Md 1; 50% Ab – Md 1,5; 100% Ab – Md 1; control – Md 2, p < 0,01). MPO activity was significantly decreased by Mu and Ab compared to control animals. Both Mu and Ab decreased expression of TNF-alpha and iNOS on tissue. It was observed a decrease on ponderal lost in experimental groups. CONCLUSIONS: Myracrodruon urundeuva and Aloe barbadensis cause important inhibitory effects in oral mucositis 5-FU induced probably by their antiinflamatory properties.