The University of Waikato, New Zealand, Honey Research Unit

 Honey as an Antiseptic Dressing

• Established Usage of Honey as a Dressing

• Importance of Antibacterial Activity

• Effectiveness against Wound-infecting Species of Bacteria

• References

 

Established Usage of Honey as a Dressing

Honey has a well established usage as a wound dressing in ancient and traditional medicine ¹⁰. In recent times this has been re-discovered, and honey is in fairly widespread use as a topical antibacterial agent for the treatment of wounds, burns and skin ulcers, there being many reports of its effectiveness ^11-23. The observations recorded are that inflammation, swelling and pain are quickly reduced, unpleasant odours cease, sloughing of necrotic tissue occurs without the need for debridement, dressings can be removed painlessly and without causing damage to re-growing tissue, and healing occurs rapidly with minimal scarring, grafting being unnecessary. In many of the cases honey was used on infected lesions not responding to standard antibiotic and antiseptic therapy. It was found in almost all of the cases to be very effective in rapidly clearing up infection and promoting healing.

 Importance of Antibacterial Activity

Much of the effectiveness of honey as a dressing appears to be due to its antimicrobial properties. The healing process will not occur unless infection is cleared from a lesion: swabbing of wounds dressed with honey has shown that the infecting bacteria are rapidly cleared ^{13, 16, 18, 20, 24}. In this respect honey is superior to the expensive modern hydrocolloid wound dressings as a moist dressing. Although tissue re-growth in the healing process is enhanced by a moist environment, and deformity is prevented if the re-growth is not forced down by a dry scab forming on the surface, moist conditions favour the growth of infecting bacteria. Antibiotics are ineffective in this situation, and antiseptics cause tissue damage, so slow the healing process ²⁵. Honey is reported to cause no tissue damage, and appears to actually promote the healing process. There are also numerous reports of sugar being used as a wound dressing, this also being found to be effective ^26-31. Antibacterial activity is attributed by several authors to the high osmolarity of the sugar or honey ^{11, 17, 22, 27}, it not being generally recognised that some honeys can have additional antibacterial activity considerably greater than that due to the osmolarity. This additional activity would be of particular significance in situations where the dressing becomes diluted by body fluids, and in regions of a lesion that are not in direct contact with the dressing. Staphylococcus aureus is exceptionally osmotolerant: for complete inhibition of its growth the a_w has to be lowered below 0.86, which would be a typical honey at 29% (v/v). In the reports of sucrose syrup or paste being used as a wound dressing it is noted that infection with Staphylococcus aureus is hard to clear. Measurements that have been reported ²⁷ of the dilution occurring from the uptake of water from surrounding tissues when an abdominal wound was packed with sugar reveal that a saturated sucrose syrup containing undissolved granules becomes diluted in 7.5 hours to a concentration that is 30% of that of a saturated solution. Although the a_w of this solution is low enough to prevent the growth of most human pathogens, it is not low enough to seriously restrict the growth of Staphylococcus aureus, a species which has developed resistance to many antibiotics and has become the predominant agent of wound sepsis in hospitals ³². But Staphylococcus aureus is one of the species most sensitive to the antibacterial activity of honey. There have been many reports of complete inhibition of Staphylococcus aureus by honeys diluted to much lower concentrations ⁴, showing the importance of the other antibacterial factors in selected honeys.

To know for certain the clinical significance of the additional antibacterial activity in honey, a clinical trial will need to be conducted to compare dressings of sugar and selected honeys. The little comparative work reported to date indicates that more rapid healing is achieved with honey than with sugar ^{12, 15}. Since infection is one of the most common impediments to wound healing ³³, then such results would be expected if the sugar dressing were not able to fully suppress the growth of bacteria as the sugar became diluted. The additional antibacterial activity of honey could be the reason for the remarkable rates of healing reported when honey has been used as a dressing ^{11, 13, 14}.

 

 Effectiveness against Wound-infecting Species of Bacteria

The seven species of bacteria most commonly involved in wound infection have been tested for their sensitivity to the antibacterial activity of honey ³⁴. The two major forms of antibacterial activity were examined separately: a honey with an average level of activity due to hydrogen peroxide and no detectable non-peroxide activity was used; also a manuka honey with an average level of non-peroxide activity, with catalase added to remove any hydrogen peroxide. The results of this study are summarised in Table 1.

Overall there was little difference between the two types of antibacterial activity in their effectiveness, although some species were more sensitive to the action of one type of honey than they were to the other. The results thus showed that these honeys, with an average level of activity, could be diluted nearly ten-fold yet still completely inhibit the growth of all the major wound-infecting species of bacteria. It is notable that the manuka honey, with an average level of activity, could be diluted with 54 times its volume of fluid yet still completely inhibit the growth of Staphylococcus aureus, the major wound-infecting species, and a species notorious for its development of resistance to antibiotics.

Table 1. The minimum concentration of honey (%, v/v) in the growth medium needed to completely inhibit the growth of various species of wound-infecting bacteria.

Bacterial Species	Manuka honey	Other honey
Escherichia coli	3.7	7.1
Proteus mirabilis	7.3	3.3
Pseudomonas aeruginosa	10.8	6.8
Salmonella typhimurium	6.0	4.1
Serratia marcescens	6.3	4.7
Staphylococcus aureus	1.8	4.9
Streptococcus pyogenes	3.6	2.6

 

There are frequent reports of hospital wards being closed because of the presence of strains of methicillin-resistant Staphylococcus aureus (MRSA). Because these strains are resistant to all of the antibiotics in common use it is necessary to protect patients with impaired immunity from exposure to them in case they contract infections which will not respond to treatment. The collection of strains of MRSA at Waikato Hospital have been tested for sensitivity to the two honeys described above ³⁵. All of the strains were found to be completely inhibited by both honeys at 10% (v/v) in the growth medium, and many of the strains by the honeys at 5% (v/v).

References

1. Dustmann J H. (1979) Antibacterial Effect of Honey. Apiacta 14, 7-11.
    
2. Majno G: The Healing Hand. Man and Wound in the Ancient World. Harvard University Press Cambridge, Massachusetts. 1975.
    
3. Ransome H M: The Sacred Bee in Ancient Times and Folklore. George Allen and Unwin London. 1937.
    
4. Molan P C. (1992) The Antibacterial Activity of Honey. 1. The Nature of the Antibacterial Activity. Bee World 73, 5-28.
    
5. Molan P C. (1992) The Antibacterial Activity of Honey. 2. Variation in the Potency of the Antibacterial Activity. Bee World 73, 59-76.
    
6. Aristotle (350 B.C.). Translated by Thompson DÕA W. Historia Animalium in: The Works of Aristotle (Smith J A, Ross W D editors) Oxford University Press Oxford 1910 Volume IV.
    
7. Gunther R T: The Greek Herbal of Dioscorides (Translated by Goodyear J, 1655). Hafner N. Y. 1934, reprinted 1959.
    
8. Allen K L, Molan P C, Reid G M. (1991) A Survey of the Antibacterial Activity of Some New Zealand Honeys. J. Pharm. Pharmacol. 43, 817-822.
    
9. Allen K L, Molan P C, Reid G M. (1991) The Variability of the Aantibacterial Activity of Honey. Apiacta 26, 114-121.
    
10. Zumla A, Lulat A. (1989) Honey - a Remedy Rediscovered. J. Royal Soc. Med. 82, 384-3
     
11. Bulman M W. (1955) Honey as a Surgical Dressing. Middlesex Hosp. J. 55, 188-189.
     
12. Hutton D J. (1966) Treatment of Pressure Sores. Nurs. Times 62, 1533-1534.
     
13. Cavanagh D, Beazley J, Ostapowicz F. (1970) Radical Operation for Carcinoma of the Vulva. A New Approach to Wound Healing. J. Obstet. Gynaecol. Br. Cmwlth. 77, 1037-1
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14. Blomfield R. (1973) Honey for Decubitus Ulcers. J. Am. Med. Assoc. 224, 905.
     
15. Burlando F. (1978) Sull'azione Terapeutica del Miele nelle Ustioni. Minerva Dermat. 113, 699-706.
     
16. Armon P J. (1980) The Use of Honey in the Treatment of Infected Wounds. Trop. Doct. 10, 91.
     
17. Bose B. (1982) Honey or Sugar in Treatment of Infected Wounds? Lancet i, 963.
    
     
18. Dumronglert E. (1983) A Follow-up Study of Chronic Wound Healing Dressing with Pure Natural Honey. J. Natl Res. Counc. Thail. 15, 39-66.
     
19. Kandil A, Elbanby M, Abd-Elwahed K, Abou Sehly G, Ezzat N. (1987) Healing Effect of True Floral and False Nonfloral Honey on Medical Wounds. J. Drug Res. (Cairo) 17, 71-
     
20. Effem S E E. (1988) Clinical Observations on the Wound Healing Properties of Honey. Br. J. Surg. 75, 679-681.
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21. Farouk A, Hassan T, Kashif H, Khalid S A, Mutawali I, Wadi M. (1988) Studies on Sudanese Bee Honey: Laboratory and Clinical Evaluation. Int. J. Crude Drug Res. 26, 161-168.
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22. Green A E.(1988) Wound Healing Properties of Honey. Br. J. Surg. 75, 1278.
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23. McInerney R J F. (1990) Honey - a Remedy Rediscovered. J. Royal Soc. Med. 83, 127.