Olive Leaf Extract Activity Against Candida Albicans and C. Dubliniensis - The in Vitro Viability Study

Acta Pharm. 2016 Sep 1;66(3):411-21. doi: 10.1515/acph-2016-0033.

Abstract

Olive leaf extract is characterized by a high content of polyphenols (oleuropein, hydroxytyrosol and their derivatives), which is associated with its therapeutic properties. The objective of the present research was to evaluate the antifungal activity of olive leaf extract against Candida albicans ATCC 10231 and C. dubliniensis CBS 7987 strains. Minimum inhibitory concentrations (MIC) of the extract were determined by several in vitro assays. The extract showed a concentration depended effect on the viability of C. albicans with MIC value of 46.875 mg mL-1 and C. dubliniensis with MIC value 62.5 mg mL-1. Most sensitive methods for testing the antifungal effect of the extracts were the trypan blue exclusion method and fluorescent dye exclusion method while MIC could not be determined by the method according to the EUCAST recommendation suggesting that herbal preparations contain compounds that may interfere with this susceptibility testing. The fluorescent dye exclusion method was also used for the assessment of morphological changes in the nuclei of treated cells. According to the obtained results, olive leaf extract is less effective against the tested strains than hydroxytyrosol, an olive plant constituent tested in our previous study.

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Antifungal Agents / chemistry
  • Antifungal Agents / pharmacology*
  • Antioxidants / chemistry
  • Antioxidants / pharmacology*
  • Candida / cytology
  • Candida / drug effects*
  • Candida / growth & development
  • Candida albicans / cytology
  • Candida albicans / drug effects
  • Candida albicans / growth & development
  • Cell Nucleus / drug effects
  • Cell Nucleus Shape / drug effects
  • Chromatography, High Pressure Liquid
  • Coloring Agents / chemistry
  • Fluorescent Dyes / chemistry
  • Iridoids / analysis
  • Microbial Sensitivity Tests / methods
  • Olea / chemistry*
  • Phenylethyl Alcohol / analogs & derivatives
  • Phenylethyl Alcohol / analysis
  • Phenylethyl Alcohol / pharmacology
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Plant Leaves / chemistry*
  • Trypan Blue / chemistry

Substances

  • Anti-Bacterial Agents
  • Antifungal Agents
  • Antioxidants
  • Coloring Agents
  • Fluorescent Dyes
  • Iridoids
  • Plant Extracts
  • 3,4-dihydroxyphenylethanol
  • 4-hydroxyphenylethanol
  • oleuropein
  • Trypan Blue
  • Phenylethyl Alcohol