Resumo

Introduction: Candida species causes a variety of infections ranging from superficial candidiasis to life-threatening invasive candidiasis and Candida albicans is a major fungal pathogen of humans. Furthermore, fungi have the genetic ability to acquire resistance to drugs used as therapeutic agents and therefore the resistance to these drugs by microorganisms has increased. Historically, plants have been an important source of natural products to improve human health and well-being. The popular use of the plant selected for this study has already previously been reported in the literature. The aim of the present study was to find out in vitro possible antifungal action and cytotoxicity of the caffeic acid in C. albicans and to evaluate their ability to interfere with the adhesion of the yeast in host cells. Materials/Methods: Cytotoxicity of caffeic acid was evaluated at concentrations from 62.5 to 0.12 mg/L in normal oral keratinocytes (NOK) by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tretazolium bromide (MTT) assay (5mg/mL). Hydrogen peroxide and doxorubicin were used as positive controls. In adhesion test was evaluated the ability of caffeic acid (15.6 mg/L) to interfere during and after the adhesion of C. albicans in NOK cells. Nine C. albicans strains were tested from the oral cavity of diabetic patients. Discussion/Results: The caffeic acid exhibited a minimum inhibitory concentration (MIC) of 15.6 mg/L, showed a strong antifungal activity. The cytotoxicity tests performed with NOK showed that the experimental substances are not cytotoxic to this cell examined, with more than 50% of cell viability in caffeic acid MIC. Furthermore the caffeic acid used at a concentration of 15.6 mg/L was able to interfere during and after the adhesion of C. albicans in NOK. It was shown that the natural substance tested for adherence was able to inhibit the binding of C. albicans in cells by 88%. On the other hand, when tested after adherence was able to promote the disconnection of C. albicans of the cells in 46% of all strains. Conclusion: The results of this study indicate the potential use of caffeic acid for the treatment of invasive candidiasis, which showed a strong antifungal activity against the fungi studied without cytotoxicity and potent ability to interfere in the fungal adhesion to host cells, initial step for the establishment of infection.