Pharmacological effect of condensed tannins extracted from Stryphnodendron adstringens: action on Candida albicans biofilm, immunomodulatory and antifungal in a murine model of vaginal candidiasis

Abstract

Vulvovaginal candidiasis (VVC) is one of the most common vaginal infections. 50-75% of women suffer from symptomatic VVC and 5% develop recurrent VVC. Approximately 90% of isolates from vaginal fluid are identified as Candida albicans and the minority of cases is caused by Candida non-albicans. Many antifungal used to treat VVC available have drawbacks such as narrow spectrum of action and toxicity. Although few resistant strains to antifungal agents have been isolated from vaginal fluid, CVV remains a common problem and often in healthy women or immunocompetent. The search for new antifungal agents has been a challenge for researchers, and several medicinal plants have been considered an excellent study. Stryphnodendron adstringens (Mart.) Coville, popularly known as "barbatimão", is a plant commonly found in the central Brazilian savannah. The stem bark of this plant are commonly used as anti-inflammatory and astringent in the treatment of wounds and vaginal infections, and some pharmacological activities been proven scientifically through laboratory tests, including antifungal activity. In 2006, our research group has shown that condensed tannins present in subfraction F2.4 obtained from the stem bark of S. adstringens showed better activity against C. albicans strains isolated from vaginal fluid with similar action of nystatin. The subfraction F2.4 interfered with cell surface hydrophobicity, adhesion, germ tube formation, alteration on the budding and cell wall of C. albicans. The inhibitory effects were attributed to the proanthocyanidin polymer composed by prodelfinidin and prorobinetinidina units and gallic acid residue with a average molecular weight of 2114 Da. To continue the evaluation of the antifungal condensed tannins extracted from bark S. adstringens this project aims to determine the effect of the F2 fraction and subfraction F2.4 on the C. albicans biofilm and to evaluate the therapeutic use of gel formulation containing condensed tannins and immunomodulatory effect in a murine model of vaginal candidiasis. (AU)