title: In Vitro Effects of Plantago Major Extract, Aucubin, and Baicalein on Candida albicans Biofilm Formation, Metabolic Activity, and Cell Surface Hydrophobicity.
abstract: OBJECTIVE
  To determine the in vitro effectiveness of Plantago major extract, along with two of its active components, aucubin and baicalein, on the inhibition of Candida albicans growth, biofilm formation, metabolic activity, and cell surface hydrophobicity.
  
  
  METHODS
  Twofold dilutions of P. major, aucubin, and baicalein were used to determine the minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and the minimum biofilm inhibitory concentration (MBIC) of each solution. Separately, twofold dilutions of P. major, aucubin, and baicalein were used to determine the metabolic activity of established C. albicans biofilm using a 2,3-bis (2- methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-carboxanilide reduction assay. Twofold dilutions of P. major, aucubin, and baicalein were used to determine the cell surface hydrophobicity of treated C. albicans biofilm by a two-phase assay using hexadecane. The hydrophobicity percentage of the cell surface was then calculated. A mixed-model ANOVA test was used for intergroup comparisons.
  
  
  RESULTS
  The MICs of P. major extract (diluted 1:2 to 1:8), aucubin (61 to 244 μg/ml), and baicalein (0.0063 to 100 μg/ml) on the total growth of C. albicans were noticeable at their highest concentrations, and the inhibition was dose dependent. The MFC was evaluated after 48 hours of incubation, and aucubin (244 μg/ml) exhibited a strong fungicidal activity at its highest concentration against C. albicans growth. The MBIC indicated no growth or reduced growth of C. albicans biofilm at the highest concentrations of aucubin (61 to 244 μg/ml) and baicalein (25 to 100 μg/ml). Similarly, the effects of these reagents on C. albicans biofilm metabolic activity and hydrophobicity demonstrated high effectiveness at their highest concentrations.
  
  
  CONCLUSIONS
  P. major extract, aucubin, and baicalein caused a dose-dependent reduction on the total growth, biofilm formation, metabolic activity, and cell surface hydrophobicity of C. albicans. This demonstrates their effectiveness as antifungals and suggests their promising potential use as solutions for C. albicans biofilm-related infections.
authors.affiliation: Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, IN.
authors.forename: Karina Pezo
authors.initials: KP
authors.lastname: Shirley
authors.affiliation: Department of Oral Biology, Indiana University School of Dentistry, Indianapolis, IN.
authors.forename: L Jack
authors.initials: LJ
authors.lastname: Windsor
authors.affiliation: Department of Biostatistics, Indiana University School of Medicine, Indianapolis, IN.
authors.forename: George J
authors.initials: GJ
authors.lastname: Eckert
authors.affiliation: Department of Oral Biology, Indiana University School of Dentistry, Indianapolis, IN.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Gregory
mesh_terms: D018441:Biofilms / Q000187:drug effects*; D002176:Candida albicans / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D002462:Cell Membrane / Q000187:drug effects; D044950:Flavanones / Q000494:pharmacology*; D057927:Hydrophobic and Hydrophilic Interactions / Q000187:drug effects; D057888:Iridoid Glucosides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology*; D010943:Plantago
chemical_list: D044950:Flavanones; D057888:Iridoid Glucosides; D010936:Plant Extracts; C006650:aucubin; C006680:baicalein
keywords: Candidiasis; antifungal; biofilm; crystal violet; denture stomatitis; hexadecane