| || || Saraf, Rajneeta.|
| || || The antimicrobial efficacy of Fiji honeys and propolis against clinical isolates from diabetic foot ulcers|
Institution: University of the South Pacific.
Subject: Honey -- Therapeutic use -- Fiji , Propolis -- Therapeutic use -- Fiji
Copyright:Under 10% of this thesis may be copied without the authors written permission
Abstract: A diverse range of illnesses have been treated with honey and propolis since ancient civilizations. There has been growing interest by health care professionals in wound care products based on New Zealand Manuka honey and Australian honey of similar Leptospermum spp. Similar interest has been evoked by propolis for its antimicrobial properties. Even though honey and propolis are both gaining popularity amongst researchers worldwide, the knowledge of the healing or antimicrobial properties of propolis is limited compared to honey. In Fiji, local honeys have been used in homes to treat diabetic foot ulcers which have failed to heal by conventional therapeutic methods. This suggests that Fiji honeys might confer antimicrobial activity against isolates from diabetic foot ulcers and the aim of the study was to investigate the efficacy of Fiji honeys as well as Fiji propolis against clinical isolates from diabetic foot ulcers. The antimicrobial activity of 30 natural honeys and two processed honeys together were determined using clinical isolates from diabetic foot ulcers namely: Staphylococcus aureus, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Klebsiella pneumoniae and Candida albicans. The antimicrobial activity of the natural honeys, determined by agar well diffusion assay and expressed as the concentration of phenol with equivalent activity, was found to be between 4.1 and 14.5% w/v phenol. The Minimum Inhibitory Concentrations (MIC) of the honeys determined by agar incorporation technique was found to range from 4.8% to more than 9.1% (v/v) honey (9.1% being the highest concentration tested). In comparison, the activities of two processed honeys were between 4.5-8.9% phenol equivalence and did not inhibit the clinical isolates from diabetic foot ulcers at the highest concentration of honey tested (9.1%). The antimicrobial activities of 70% ethanol extract of propolis (EEP) and 40% EEP were determined by disc diffusion. The mean zones of inhibition of 70% EEP were in the range from 20.4 mm ± 0.20 to 41.3mm ± 0.60 and for 40% EEP ranged from 17.8mm ± 0.30 to 22.0mm ± 0.80. This shows that the activity of 70% EEP was greater than the activity for the 40% EEP. The results also demonstrate that Fiji propolis is effective as an antimicrobial agent against clinical isolates from diabetic foot ulcers. In comparison the mean zones of inhibition for Fiji honeys was found to be between 28.2mm ± 0.50 to 38.5mm ± 0.24. There was significant difference between the antimicrobial activities of Fiji honeys and propolis. The effects of storage and heating were also examined for six selected honeys. Honeys were heated at 800C for 1 hour and the activity was determined by agar well diffusion assay. For the effects of storage on the antimicrobial activities, six honeys were stored for 10, 8, 5, 3 and 2 years and for 7 months respectively. The activities of the six honeys prior to storage and after the storage period were determined using agar well diffusion assay. The activities of the heated honeys were in the range from not being detectable to 7.2% phenol with equivalent activity (Not detectable implies having activity of less than 4.1% phenol activity) and for the stored honeys to be in the range from not being detectable to 12.3% phenol activity. The MICs determined by agar incorporation technique for the six heated honeys was found to range from 9.1% to more than 9.1% (v/v) honey and for the stored honeys to range from 7.0% to more than 9.1% (v/v) honey. This implies that heating and storage of honeys lead to reduced efficacy against isolates from diabetic foot ulcers. However, the results also indicate that the loss of antimicrobial activity is significantly greater through heating then through storage. The region providing the most potent honey was assessed in this study. It was found that honey from Kabara, Lau region had the highest activity against three isolates (S. aureus, P. aeruginosa and K. pneumoniae) from diabetic foot ulcers and thus was the most potent among the other 31 honeys analyzed.The results of this study demonstrate that Fiji honeys and propolis have potential as herbal remedies for the treatment of diabetic foot ulcers. However, to assess the true potential of Fiji honeys and Fiji propolis on diabetic foot ulcers, there is a need for actual clinical trials on these wounds.