title: Effects of magnolol and honokiol on adhesion, yeast-hyphal transition, and formation of biofilm by Candida albicans.
abstract: BACKGROUND
  The first step in infection by Candida albicans is adhesion to host cells or implanted medical devices and this followed by hyphal growth and biofilm formation. Yeast-to-hyphal transition has long been identified as a key factor in fungal virulence. Following biofilm formation, C. albicans is usually less sensitive or insensitive to antifungals. Therefore, development of new antifungals with inhibitory action on adhesion, yeast-hyphal transition and biofilm formation by C. albicans is very necessary.
  
  
  METHODS
  The effects of magnolol and honokiol on hypha growth were investigated using different induction media. Their inhibitory effects were determined using the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5- carboxanilide assay, and biofilm thickness and viability were observed by a confocal scanning laser microscope. Mammalian cells were used in adhesion assays. Genes related to hyphae development and cell adhesions were analyzed by real-time reverse transcription-polymerase chain reaction. The exogenous cyclic adenosine monophosphate was used to determine the mechanisms of action of magnolol and honokiol. Caenorhabditis elegans was used as an in vivo model to estimate the antifungal activities of magnolol and honokiol.
  
  
  CONCLUSIONS
  Magnolol and honokiol inhibited adhesion, the transition from yeast to hypha, and biofilm formation by C. albicans through the Ras1-cAMP-Efg1 pathway. Moreover, magnolol and honokiol prolonged the survival of nematodes infected by C. albicans. Magnolol and honokiol have potential inhibitory effects against biofilm formation by C. albicans.
  
  
  CONCLUSIONS
  This study provides useful information towards the development of new strategies to reduce the incidence of C. albicans biofilm-associated infection.
authors.affiliation: Department of Pharmacology, Medical School of Southeast University, Nanjing, China.
authors.forename: Lingmei
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Pathology and Pathophysiology, Medical School of Southeast University, Nanjing, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liao
authors.affiliation: Key Laboratory of Developmental Genes and Human Disease in Ministry of Education, Medical School of Southeast University, Nanjing, China.
authors.forename: Dayong
authors.initials: D
authors.lastname: Wang
mesh_terms: D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D001713:Biphenyl Compounds / Q000737:chemistry / Q000494:pharmacology*; D017173:Caenorhabditis elegans / Q000382:microbiology; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D004365:Drugs, Chinese Herbal; D005656:Fungal Proteins / Q000378:metabolism; D025301:Hyphae / Q000187:drug effects / Q000254:growth & development; D017705:Lignans / Q000737:chemistry / Q000494:pharmacology*; D018613:Microscopy, Confocal; D023421:Models, Animal; D051381:Rats; D015398:Signal Transduction / Q000187:drug effects; D014025:Titanium / Q000737:chemistry; D014774:Virulence / Q000187:drug effects; D000498:Allyl Compounds; D010636:Phenols
chemical_list: D000935:Antifungal Agents; D001713:Biphenyl Compounds; D004365:Drugs, Chinese Herbal; D005656:Fungal Proteins; D017705:Lignans; D014025:Titanium; C005498:magnolol; C005499:honokiol; D000498:Allyl Compounds; D010636:Phenols