Potent antifungal activity of extracts and pure compound isolated from pomegranate peels and synergism with fluconazole against Candida albicans.
Activity-guided repeated fractionation of crude hydro alcoholic extract prepared from the fruit peel of Punica granatum on a silica-gel column yielded a compound that exhibited strong antifungal activity against Candida spp. Based on spectral analyses, the compound was identified as punicalagin. Punicalagin showed strong activity against Candida albicans and Candida parapsilosis, with MICs of 3.9 and 1.9 microg/ml, respectively. The combination of punicalagin and fluconazole showed a synergistic interaction. MIC for fluconazole decreased twofold when combined with the extract. The FIC index was 0.25. The synergism observed in disk-diffusion and checkerboard assays was confirmed in time-kill curves. The effect of punicalagin on the morphology and ultrastructure in treated yeast cells was examined by scanning and transmission electron microscopy. An irregular budding pattern and pseudohyphae were seen in treated yeasts. By transmission electron microscopy, treated cells showed a thickened cell wall, changes in the space between cell wall and the plasma membrane, vacuoles, and a reduction in cytoplasmic content. Since the punicalagin concentration effective in vitro is achievable in vivo, the combination of this agent with fluconazole represents an attractive prospect for the development of new management strategies for candidiasis, and should be investigated further in in vivo models.
Endo
Eliana Harue
EH
Programa de Pós-graduação em Ciências Farmacêuticas, Universidade Estadual de Maringá, Av. Colombo, 5790, 87020-900 Maringá, PR, Brazil.
Cortez
Diógenes Aparício Garcia
DA
Ueda-Nakamura
Tânia
T
Nakamura
Celso Vataru
CV
Dias Filho
Benedito Prado
BP
D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002175:Candida / Q000187:drug effects* / Q000648:ultrastructure; D002176:Candida albicans / Q000187:drug effects* / Q000648:ultrastructure; D002855:Chromatography, Thin Layer; D025141:Drug Resistance, Fungal; D004357:Drug Synergism; D015725:Fluconazole / Q000494:pharmacology*; D047348:Hydrolyzable Tannins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D029561:Lythraceae / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D019441:Plant Epidermis / Q000737:chemistry
D000935:Antifungal Agents; D047348:Hydrolyzable Tannins; C115642:punicalagin; D015725:Fluconazole