AVALIAÇÃO IN VITRO DA ATIVIDADE ANTIFÚNGICA DE EXTRATOS VEGETAIS SOBRE CANDIDA SPP.

Abstract

Candida yeasts are often associated with normal oral mucosa. However, in specific situations, such as immunological, chemical and mechanical changes, can trigger infections called candidiasis. When associated with the use of prostheses, candidiasis is called denture stomatitis. Candida biofilm is considered the main etiological factor in denture stomatitis basis of the prosthesis and its removal is necessary by the use of chemical cleaners associated or not to antifungal agents. Given this, the objective of this study was to evaluate the antifungal potential of plant extracts on Candida spp. and on biofilm formed in acrylic resin specimens. We conducted laboratory study, in vitro, by analyzing the performance of plant extracts (Passiflora edulis leaves and Psidium guajava L., peel Schinus terebinthifolius Raddi, mesocarp Orbignya phalerata Mart. And leaves and bark of Anacardium occidentale L. ) at a concentration of 100mg / ml of standard strains C. albicans (ATCC90028) and C. glabrata (ATCC2001). The antimicrobial activity was evaluated by the agar diffusion method, determination of minimum inhibitory concentration (MIC) by microdilution broth method, followed by the subcultures in agar to determine the concentration Fungicide Min. The positive controls were 0.12% chlorhexidine gluconate and fluconazole 128 mg / mL. It was also evaluated the effect of Psidium guajava extract of C. albicans biofilm (ATCC90028) formed on acrylic resin specimens. The specimens were submitted to the treatments: herbal extract of Psidium guajava in the concentration of 300mg / ml (15 min); Sodium hypochlorite (NaOCl) 0.5% (10 min) as positive control and negative control as distilled and deionized water (15 min). The number of viable Candida cells was expressed as colony forming units (CFU) / mm2. The Psidium guajava L. extract presented halos of inhibition of 17.08 mm for C. albicans and C. glabrata to 20.41 mm. The other extracts did not form inhibition zones for the tested strains. The MIC and MFC of Psidium guajava extract for C. albicans was 15mg / ml and 30mg / ml respectively and C. glabrata 3.75mg / ml and 15mg / ml. With respect to the effect of the extract on the biofilm, it was observed a significant reduction in CFUs acrylic resin specimens when compared to the negative control group. It was concluded in this study that the extract of Psidium guajava leaves showed antifungal activity against strains of C. albicans and C. glabrata and that it significantly reduced the biofilm formed on the acrylic resin specimens.