Study of the antifungal potential of (r)-(+)-citronellal and its association with therapeutic agents used in the treatment of vulvovaginal candidiasis
Keywords:Monoterpenoid, Anti-C. albicans, Antifungal agents, Secondary metabolites, Citronellal
Vulvovaginal candidiasis (VVC) is a common fungal infection that affects healthy women of all ages. At least 75% of women will develop one or more infections once during their lifetime, with 6 to 9% of those individuals developing recurrent infections. In view of this context, this study sought to evaluate the antifungal potential of the isolated (R)-(+)-citronellal [(R)-(+)-CT] and associated to therapeutic agents of clinical importance. The enantiomer was solubilized in tween 80 and dimethylsulfoxide (DMSO). Posteriorly diluted in sterile distilled water up to the concentration of 2048Âµg/mL. The minimum inhibitory concentration (MIC) of the product was determined by microdilution in RPMI-1640 obtaining dilutions of 1024-4Âµg/mL. The minimum fungicidal concentration (MFC) was determined by the Sabouraud dextrose agar (SDA) depletion technique from aliquots of 1ÂµL of the MIC, MIC Ã— 2 and MIC Ã— 4. The MIC and the MFC values of (R)-(+)-CT for 90% of the C. albicans strains were 16 and 32Âµg/mL respectively. In the susceptibility test, C. albicans presented a high resistance to fluconazole and to itraconazole, 12 (92.30%) of the strains. However, for ketoconazole and miconazole the resistance was of 4 (30.76%) and 3 (23.07%) of the strains respectively. In the combination testing of the (R)-(+)-CT with ketoconazole and miconazole, the resistance was completely reverted. For fluconazole and itraconazole, the resistance was reverted in 9 (75%) and 7 (58.33%) of the strains respectively. The (R)-(+)-CT presented fungicide activity with MFC of MIC Ã— 2. When in combination with ketoconazole, fluconazole, itraconazole and miconazole increased the inhibition zones of these antifungal drugs, reducing the resistance against C. albicans.