Proanthocyanidin polymeric tannins from Stryphnodendron adstringens are effective against Candida spp. isolates and for vaginal candidiasis treatment.

ETHNOPHARMACOLOGICAL RELEVANCE: The stem bark of Stryphnodendron adstringens (Mart.) Coville is popularly used as anti-inflammatory, astringent and in the treatment of wounds and vaginal infections. Several pharmacological activities have been scientifically proven by in vitro and in vivo experimental assays for antibacterial, antiviral, antiprotozoan, anti-inflammatory and antioxidant. AIM OF THE STUDY: We investigated whether proanthocyanidin polymeric tannins from the Stryphnodendron adstringens stem bark with antifungal activity against Candida albicans in vitro are also active against planktonic and biofilm cells of Candida non-albicans (CNA, including fluconazole-resistant isolates) and are capable of controlling Candida vaginitis in vivo. MATERIALS AND METHODS: A total of 46 clinical isolates and 5 reference Candida spp. strains were used in this study. The antifungal effects in vitro of tannins (F2 and sub-fraction F2.4) from S. adstringens stem bark were evaluated using a broth microdilution assay (for planktonic yeasts and biofilm dispersion cells) or by XTT assay (for biofilm sessile cells). For in vivo antifungal activity analysis, mice with vaginal infection by C. albicans or C. glabrata were treated with a topical gel containing F2 (alone or combined with oral fluconazole), and the vaginal histopathology and fungal burden (by CFU counts from vaginal homogenates) were analyzed. RESULTS: F2 and F2.4 inhibited the proliferation of planktonic cells of Candida spp., especially that of fluconazole- and/or amphotericin B-resistant isolates. F2 and F2.4 also inhibited the proliferation of Candida biofilm dispersion cells. Moreover, a gel containing F2 efficiently controlled vaginal infection by C. albicans and C. glabrata in mice, with no noticeable toxicity to vaginal tissue. CONCLUSIONS: Our data show that proanthocyanidin polymeric tannins obtained from S. adstringens have antifungal activity in vitro against C. albicans and CNA (including fluconazole-resistant isolates) and presented efficacy in the control of candidiasis in murine model. Therefore, these tannins have potential use in the treatment of vaginal candidiasis, representing interesting alternatives to current antifungals.

Influence of melaleuca and copaiba oils on Candida albicans adhesion.

OBJECTIVE: To evaluate the efficacy of Melaleuca alternifolia and Copaifera officinalis in inhibiting the adhesion of Candida albicans biofilm. BACKGROUND: Over 65% of denture wearers suffer from denture stomatitis, which is one of the most prevalent forms of oral candidiasis. This disease is characterised by the inflammation of the oral mucosa in contact with the contaminated denture. The contaminated denture contributes to the switch of C. albicans from yeast to its pathogenic hyphal form. Candida albicans adheres and colonises the polymethylmethacrylate resin surfaces and thus contributes to the development of denture stomatitis. MATERIALS AND METHODS: The minimal inhibitory concentration (MIC) of M. alternifolia and Co. officinalis was assessed by the agar dilution method. Sixty-six thermopolymerised acrylic resin squares were used and treated with phosphate-buffered saline, sodium hypochlorite 1%, melaleuca 0.75%, melaleuca 0.375%, melaleuca 0.188% and copaiba 10%. For adherence and biofilm formation, the treated squares were placed in six-well tissue culture plates containing 1 × 10(7)  cells/ml of ATCC1023 or SC5314 in Roswell Park Memorial Institute (RPMI) medium, and after 12 h, the planktonic cells were counted. RESULTS: Copaiba oil did not inhibit C. albicans growth. However, melaleuca oil showed an MIC value of 0.375% (3.4 mg/ml) for ATCC10231 and 0.093% (0.84 mg/ml) for SC5314. CONCLUSIONS: Our results demonstrated that M. alternifolia oil inhibited the growth of C. albicans. Moreover, both oils promoted significant adhesion reduction in the tested strains. These findings suggest the possibility of using these oils in prophylaxes against candidiasis.