Resumo

Pythiosis is a granulomatous disease that affect both human and animals. It is caused by Pythium insidiosum, an aquatic oomycete which infective form correspond to the biflagelate zoopspores. Its treatment is difficult, because topic and sistemic antifungal drugs are of little effectiveness due to ultraestructural differences between oomycetes and true fungi. In the majority of cases radical surgery is needed, a limited approach depending on the site and the size of the lesion. Since treatment represents the great challenge in pythiosis, the search of new compouds is extremely welcome. The aim of this study was to evaluate the effect of clove oil and eugenol on in vitro growth of hyphae of P. insidiosum. Ten isolates of P. insidiosum were tested with essencital oil of clove (Sizygium aromaticum), as well as purified eugenol (Sigma-Aldrich). The isolates were mantained into Sabouraud Dextrose (SAB) Agar at 35ºC for 7 days and standardized fragments of 5 mm of diameter were removed and tested in v/v concentrations of 0,001, 0,01, 0,05, 0,1, 0,25, 0,5, 1,0, 2,5, 5,0 e 10%, dilluted in SAB broth and 1% of Tween. The fragments were kept under constant homogenization at 35ºC for 24 h and then each fragment was individualy cultured in SAB agar at 35ºC for seven days. Control group of each isolate consisted in homogenization of the standardized fragments in SAB broth with Tween. It was observed slow growth of the patogen in clove oil at 0,001% during the first 48 hours, but the growth was recovered similarly to control group by the end of the seventh day. For eugenol, it was observed no growth for all concentrations evaluated, as well as for 0,01 and above of clove oil. Clove oil contains several compouds and eugenol is the major one. Some applications of this compound may be observed by its anesthetic, anti-inflammatory, anti-thrombotic, insecticide, antiseptic dentistry, anti-allergic and also antimicrobial. The bactericidal effect was proven for Staphylococcus aureus, Escherichia coli and Pseudomonas spp. In mycology, its effects were evaluated in Candida spp., Aspergillus spp., and some dermatophytes, however, its effect on P. insidiosum is unpublished. Althogh preliminary, this study points to the desirable inhibition growth effect on hyphae of the pathogen and may become an attractive alternative compound to be evaluated for treatment of pythiosis.