Potential Antifungal activity of plant extracts against Candida albicans
Superficial candidiasis is the most common fungal infection of skin, oral and vaginal mucosa, being Candida albicans the most frequently isolated species [1]. In addition to conventional and pharmacologically proven therapeutic measures, solutions based on natural products are used as antimicrobials [2], and medicinal plants constitute an important source of new biologically active compounds. Based on an ethnobotanical survey of plants used by the Brazilian population in the treatment of signs and symptoms related to fungal infections [3,4], eigth plant species were selected for evaluation regarding their potential antifungal effect against cell of C. albicans. In this study, the potential antifungal effect of extracts from Gossypium hirsutum L., Arctium lappa, Equisetum sp., Cecropia pachystachya Trécul.,Eythrina verna, Gallesia integrifolia (Spreng.) Harms, Ipomoea alba L., Melissa officinalis and Pogostemon heyneanus were evaluated against 75 clinical C. albicans strains isolated from superficial candidiasis, using Minimal Inhibitory Concentration (MIC), according to document M27- A3 (CLSI, 2008)[4]. The leaves were collected, dried, ground, separately, ovendried at temperature under 40 ºC and powdered using knife mill. The powdered material was macerated using 95% etanol as solvent at room temperature. The extracts were then filtered, concentrated under vacuum in rotatory evaporator and kept at 4 ºC. To determine the minimal MIC of the plant extracts, ten two-fold serial dilutions were performed in RPMI 1640 medium, starting from the concentration of 2 µg/mL. After incubation for 24 h at 35 ºC, the MIC of the extract was determined as the lowest concentration capable of totally inhibiting fungal growth. In parallel, the activity the solvent used in the solubilization of the extracts, was also evaluated. The assays were performed in duplicate. All extracts presented antifungal action. The most promising results on Candida albicans cells were obtained with Cecropia pachystachya Trécul extract, with MIC values between 7.81 and 3.91 µg/mL. In conclusion these results show that some plant extracts have potential clinical use in the prevention and treatment of superficial candidiasis