title: Proanthocyanidins polymeric tannin from Stryphnodendron adstringens are active against Candida albicans biofilms.
abstract: BACKGROUND
  Biofilm formation is important in Candida albicans pathogenesis and constitutes a mechanism of antifungal resistance. Thus, we evaluated the effect of proanthocyanidins polymer-rich fractions from Stryphnodendron adstringens (fraction F2 and subfraction F2.4) against C. albicans biofilms.
  
  
  METHODS
  Firstly, the antifungal activity of F2 and F2.4 against planktonic cells of Candida albicans (ATCC 10231) was determined using broth microdilution method. Anti-biofilm effect of F2 and F2.4 was evaluated during biofilm formation or on mature biofilm of C. albicans and compared with standard antifungals amphotericin B and fluconazole. Metabolic activity of sessile and dispersion cells from biofilms after antifungal treatments were measured using a tetrazolium reduction assay and the biofilm total biomass was quantified by crystal violet-based assay. Morphological alterations after treatments were observed using scanning electron microscopy.
  
  
  RESULTS
  The anti-biofilm effect of F2 and F2.4 were comparable to standard antifungals (amphotericin B and fluconazole). F2 and F2.4 treatments reduced biofilm metabolic activity (in sessile and in dispersion cells) during biofilm formation, and in mature biofilms, unlike fluconazole, which only prevents the biofilm formation. Treatments with F2, F2.4 or fluconazole reduced biofilm biomass during biofilm formation, but not in mature biofilm. Amphotericin B presented higher inhibitory effect on biofilm formation and on mature biofilm of C. albicans. F2 and F2.4 treatments led to the appearance of dumbbell-shaped blastoconidia and of blastoconidia clusters in biofilms.
  
  
  CONCLUSIONS
  Proanthocyanidins polymer-rich fractions from S. adstringens successfully inhibited C. albicans planktonic growth and biofilm development, and they represent a potential new agent for the treatment of biofilm-associated candidiasis.
authors.affiliation: Laboratório de Biologia Celular de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. raulealuiz@gmail.com.
authors.forename: Raul Leal Faria
authors.initials: RL
authors.lastname: Luiz
authors.affiliation: Laboratório de Biologia Celular de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. taissavila@gmail.com.
authors.forename: Taissa Vieira Machado
authors.initials: TV
authors.lastname: Vila
authors.affiliation: Laboratório de Biologia Farmacêutica, Palafito, Departamento de Farmácia Universidade Estadual de Maringá, PR, Brazil. mello@uem.br.
authors.forename: João Carlos Palazzo
authors.initials: JC
authors.lastname: de Mello
authors.affiliation: Laboratório de Inovação Tecnológica no Desenvolvimento de Fármacos e Cosméticos, Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, PR, Brazil. cvnakamura@uem.br.
authors.forename: Celso Vataru
authors.initials: CV
authors.lastname: Nakamura
authors.affiliation: Laboratório de Biologia Celular de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil. rozental@biof.ufrj.br.
authors.forename: Sonia
authors.initials: S
authors.lastname: Rozental
authors.affiliation: Laboratório de Quimioterapia Antifúngica, Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1374, 05508-900, SP, Brazil. ishidakelly@usp.br.
authors.forename: Kelly
authors.initials: K
authors.lastname: Ishida
mesh_terms: D000666:Amphotericin B / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002176:Candida albicans / Q000187:drug effects* / Q000254:growth & development; D007887:Fabaceae / Q000737:chemistry*; D015725:Fluconazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D044945:Proanthocyanidins / Q000494:pharmacology*; D013634:Tannins / Q000494:pharmacology; D013778:Tetrazolium Salts
chemical_list: D000935:Antifungal Agents; D010936:Plant Extracts; D044945:Proanthocyanidins; D013634:Tannins; D013778:Tetrazolium Salts; D000666:Amphotericin B; D015725:Fluconazole