Antifungal Activity of Maleic Acid against Candida spp Associated with Oral Infections

Abstract

Objective: To determine in vitro the antifungal activity of maleic acid contained in apple vinegars by the establishment of its minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC). Method: This investigation was a laboratory, experimental research with an inductive approach and intensive direct observation. A commercial apple vinegar (Minhoto®) containing maleic acid with initial concentration of 4% was used. Eight Candida strains were tested in the assays, being five Candida albicans and three Candida tropicalis. The MIC was determined by the microdiluition technique in Sabourand Dextrose broth, and, sequentially, the MFC was determined, using the principles of the same technique. Results: The MIC of apple vinegar was 2,500 µg/mL for all strains. Regarding MFC, Candida tropicalis ATCC 13803 was sensitive to a concentration of 10,000 µg/mL, while Candida tropicalis 33 and Candida albicans LM were sensitive to concentrations from 615 to 5,000 µg/mL. For the other strains, a MFC of 2,500 µg/mL was obtained. Nystatin presented MIC of 3,125 µg/mL for the eight test strains and MFC values ranging from 3,125 µg/mL to 12.5 µg/mL. Conclusion: Considering the obtained results, apple vinegar presents fungicidal and fungistatic actions, which provide evidence for evaluation of this agent when in contact with denture bases, and treats oral mycotic infections. However, several assays are needed to investigate the behavior of apple vinegar in contact with the oral cavity and the denture base materials in order to determine its correct mode of use to obtain excellence in the outcomes.