Antimicrobial activity of quality brands Spanish honeys Conference Paper uri icon


  • 80-90% of patients with head and neck cancer who receives radiation and/or chemotherapy have oral mucositis. Oral mucositis is a complex process involving oxidative damage of oral mucosal, inflammation, mucosal colonization by pathogenic microorganisms and direct damage to DNA. The development of oral mucositis led to the interruption of the treatments, periods of hospitalization, dysphagia with malnutrition in patients and increased healthcare costs in treatments which have isolated mechanisms of action and are not fully satisfactory. As honey has antioxidant, anti-inflammatory, antimicrobial and healing properties, it can be used effectively in the prevention and treatment of oral mucositis by acting simultaneously on different pathophysiological mechanisms. The aim of this study was to evaluate the antimicrobial activity of honeys from different floral sources and to evaluate the possible differences that may happen in such capacity between similar honeys of different years of production. We selected six types of Spanish honey from quality brands avocado honey (Persea sp.) and chestnut honey (Castanea sp.) from DOP Miel de Granada; lavender honey (Lavandula sp.) and rosemary honey (Rosmarinus officinalis) from DOP Miel de La Alcarria; blackberry honey (Rubus sp.) and eucalyptus honey (Eucalyptus sp) from PGI Miel de Galicia and two organic honey, thyme honey (Thymus sp.) and heather honey (Erica sp.), collected during two consecutive harvests (2010 and 2011). We studied antimicrobial activity against microorganisms isolated from oropharyngeal mucosa of patients who suffer oral mucositis, Gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli) and yeasts (Candida albicans and Candida glabrata). These assays gave us accurate information about what would be expected from the application of honey in those patients. Antimicrobial test were carried out according to Silva et al. (2012) using Nutrient Broth or Brain Heart Infusion to bacterias or Yeasts Peptone Dextrose to yeasts on microplates (96 wells). Honey was diluted in water and transferred into the first well. Serial dilutions were performed. 20 μl of a solution of 1% TTC was used for detect antimicrobial activity Candida albicans and Candida glabrata showed higher resistance and their growth was not inhibited at the honey concentrations used. Further studies using higher concentrations of honey are required. Among bacteria all the tested honeys were able to inhibit their growth but showed different antimicrobial activity depending on the microorganism tested. Minimum inhibitory concentration ranged from 3.9 to 250 mg/ml. Generally gram-negative bacteria were less resistant, something that can be explained by the variability that exists in the resistance in bacterial strains within a specie. Differences were also observed in the antimicrobial activity of similar honeys from different years of production. Being a natural product, honey’s composition is in a constant state of change, depending on factors such as climatology which affect plant species available.

publication date

  • January 1, 2012