What's special about Active Manuka Honey?

Waikato Honey Research Unit

| Waikato Honey Research Unit |

What's special about Active Manuka Honey?

For the past 28 years honey researchers at the University of Waikato have been investigating what many local New Zealanders have accepted as common wisdom: our local manuka honey is a superior treatment for wound infections. Manuka honey is gathered in New Zealand from the manuka bush, Leptospermum scoparium, which grows uncultivated throughout the country. (More recently, as a result of systematic screening of Australian honeys, a honey with the same properties has been found to be produced from Leptospermum polygalifolium, which grows uncultivated in a few parts of Australlia - this is called "jellybush" honey.)

After the results of this work became known through publications in scientific journals, many people contacted the Honey Research Unit to find out what is so special about Active Manuka Honey. The pertinent facts are:

• All honeys have an antibacterial activity, due primarily to hydrogen peroxide formed in a "slow-release" manner by the enzyme glucose oxidase present in honey, which can vary widely in potency. Some honeys are no more antibacterial than sugar, while others can be diluted more than 100-fold and still halt the growth of bacteria. The difference in potency of antibacterial activity found among the different honeys is more than 100-fold.
• Manuka honey (and some of its Australian equivalent) contains a high level of additional, non-peroxide, antibacterial components. Although some other types of honey have been reported to have some non-peroxide antibacterial activity, this is at a very low level. The high level of non-peroxide activity found in honey produced from Leptospermum species is unique.
• It is now known that this non-peroxide activity is due to the combined action of methylglyoxal (MGO) and an unidentified synergistic component. Although very low levels of MGO are found in most honey, the high level of MGO in manuka honey is unique, as is the presence of the synergist which more than doubles the antibacterial activity of MGO. (Jellybush honey is yet to be investigated for this.)
• Only some of the honey sold as manuka honey (likewise only some jellybush honey) has this non-peroxide type of antibacterial activity.
• The term “Active Manuka Honey” was devised to distinguish manuka honey with this non-peroxide type of antibacterial activity from what was being sold as manuka honey that did not have this activity. This term has been in use in publications since 1998.
• Confusingly there is now honey being sold as “Active Manuka Honey” where the seller is referring to antibacterial activity that is due to hydrogen peroxide just like in all other types of honey, and not to the non-peroxide type of antibacterial activity that is unique to manuka honey and jellybush honey.
• Our research, investigating manuka honey collected from many sites over a large area of New Zealand, has shown that the level of the non-peroxide antibacterial activity in manuka honey depends to some degree on the variety of manuka the honey is collected from, but mainly on the proportion of manuka nectar in the honey.
• Honey sold as manuka honey which does not have a measurable level of the non-peroxide antibacterial activity is thus likely to have been produced predominantly from nectar sources other than manuka.
• Importantly, the non-peroxide type of antibacterial activity in manuka honey is not affected by the catalase enzyme present in body tissue and serum. This enzyme will break down, to a large degree, the hydrogen peroxide which is the major antibacterial factor found in other types of honey. (See Photo 1 below.) If a honey without the non-peroxide antibacterial activity fpund only in manuka honey and jellybush honey were used to treat an infection, the potency of the honey's antibacterial activity would most likely be reduced because of the action of catalase.
• The enzyme that produces hydrogen peroxide in honey is destroyed when honey is exposed to heat and light. But the non-peroxide antibacterial activity of manuka honey is stable, so there is no concern about true Active Manuka Honey losing its activity in storage.
• The enzyme that produces hydrogen peroxide in honeys becomes active only when honey is diluted. But the non-peroxide antibacterial activity is at full strength in undiluted manuka honey, which will provide a more potent antibacterial action diffusing into the depth of infected tissues. (See Photo 2 below.)
• The enzyme that produces hydrogen peroxide in honeys needs oxygen to be available for the reaction, so may not work under wound dressings or in wound cavities or in the gut. Active Manuka Honey, which contains the non-peroxide antibacterial activity, is active in all situations.
• The enzyme that produces hydrogen peroxide in honeys becomes active only when the acidity of honey is neutralised by body fluids, but then the honey is diluted.
• The enzyme that produces hydrogen peroxide in honeys is inactive in the acidity of the stomach.
• The enzyme that produces hydrogen peroxide in honeys could be destroyed by the protein-digesting enzymes that are in wound fluids.
• The non-peroxide antibacterial activity of Active Manuka Honey diffuses deeper into skin tissues than does the hydrogen peroxide from other types of honey.
• Active Manuka Honey, with its non-peroxide, antibacterial activity, is more effective than honey with hydrogen peroxide against some types of bacteria. For example, it is about twice as effective as other honey against Eschericihia coli and Enterococci, common causes of infection in wounds. It is much more effective than other honey against Helicobacter pylori, a common cause of peptic ulcers.

The potency of the non-peroxide antibacterial activity in Active Manuka Honey is measured by an assay developed by the Honey Research Unit:

• The killing power of samples of honey tested against the most common wound-infecting species of bacteria, Staphylococcus aureus.
• It is compared with that of solutions of a standard antiseptic, phenol (also known as carbolic acid) at various concentrations. (See Photo 3 below.)
• This is done with the enzyme catalase added to the samples of honey so that all hydrogen peroxide is destroyed and thus only the non-peroxide antibacterial activity of manuka honey is seen.
• The non-peroxide antibacterial activity of manuka honey is then reported as the equivalent concentration of phenol with the same level of antibacterial activity. (For example, an Active Manuka Honey rated as 10 for its non-peroxide antibacterial activity will kill Staph. aureus as effectively as will a 10% phenol solution.)

This bioassay of antibacterial activity has recently had its accuracy improved, and the improved method will be used for the certification by the University of Waikato of the rating of the non-peroxide antibacterial activity on jars of Active Manuka Honey being sold world-wide. (See Rating the antibacterial activity of manuka honey for details of this development.)

Many medical professionals are using Active Manuka Honey (the genuine sort) - and are getting excellent results in patients with infected wounds that have not responded to any standard treatment such as antibiotics. For most of the various brands of registered medical products based on honey that are sold for wound treatment and ophthalmology the manufacturers have opted to use Active Manuka Honey (with an activity rating ranging from 12 to 18).

None of the results being obtained clinically should be considered evidence that Active Manuka Honey is more effective than other honey - a comparative clinical trial will be needed to establish that. Nevertheless, there are good theoretical reasons for choosing to use Active Manuka Honey with a good level of the non-peroxide antibacterial activity for management of wound infections.

To alleviate any concern over the possible risk of introducing infection by the use of an unprocessed natural product on wounds, we investigated ways of sterilising honey without loss of any of its antibacterial activity. We found that honey can be sterilised by gamma irradiation without loss of activity. Active Manuka Honey, as plain honey and in manufactured wound dressings, is commercially available sterilised in this way. (See http://bio.waikato.ac.nz/honey/where.shtml .)

Photo 1:  Hydrogen peroxide is rapidly broken down (to oxygen and water) when it is exposed to the activity of the enzyme catalase present in a small drop of blood on a pricked finger.

Photo 2:  A model of honey dressings at work on an infected wound. The dressing material was impregnated with manuka honey or with clover honey, each honey having the same level of antibacterial activity in a standard laboratory assay of total antibacterial activity. The agar had been seeded with Staphylococcus aureus, which grew to form visible colonies when the plate was incubated.

Photo 3:  Measurement of the potency of the antibacterial activity of solutions of honey, and of the standard antiseptic phenol, which had been put in the wells cut in the agar plate before the plate was incubated. The agar had been seeded with Staphylococcus aureus, which grew to form visible colonies when the plate was incubated. The bacteria did not grow in the zones where antibacterial activity was diffusing out into the agar from the wells.

轉譯 *********

懷卡托蜂蜜研究組

|懷卡托蜂蜜研究組 |
有什麼特別活動麥盧卡蜂蜜？

在過去的28年蜂蜜的研究人員在懷卡托大學一直在調查了許多地方新西蘭人已接納共同的智慧：本地麥盧卡蜂蜜是一種高級的治療傷口感染。麥盧卡蜂蜜聚集在新西蘭的麥盧卡灌木，麥盧卡棒，它生長荒地在全國各地。 （最近，由於系統的檢查結果澳大利亞蜂蜜，蜂蜜具有相同屬性已被發現生產的麥盧卡 polygalifolium，而生長在荒地數部分Australlia - 這被稱為“jellybush”蜂蜜。）

結果後，這項工作被稱為通過出版物在科學期刊上，很多人接觸蜂蜜研究小組找出特別之處，主動麥盧卡蜂蜜。的相關事實是：

    *所有蜂蜜具有抗菌活性，這主要是由於過氧化氫組成的“緩釋”的方式由葡萄糖氧化酶存在於蜂蜜，可廣泛應用於不同的效力。有些蜂蜜抗菌沒有更多的比蔗糖，而其他可稀釋 100倍，仍停止生長的細菌。效價的差別發現抗菌活性在不同蜂蜜超過 100倍。
    *麥盧卡蜂蜜（和它的一些澳大利亞等值）包含一個高層次的增加，非氧化，抗菌成分。儘管一些其他類型的蜂蜜已報告有一些非氧化抗菌活性，這是在非常低的水平。高層次的非氧化活性發現麥盧卡蜂蜜生產的物種是獨一無二的。
    *現在已經知道，這種非氧化活性是由於聯合行動醛（氧化鎂）和一個身份不明的協同組成部分。雖然很低的水平氧化鎂發現在大多數蜂蜜，高水平的MgO在麥盧卡蜂蜜是獨一無二的，因為是存在的增效劑的一倍以上抗菌活性氧化鎂。 （Jellybush蜂蜜尚未追究這一點。）
    *只有某些蜂蜜出售，麥盧卡蜂蜜（也只有一些jellybush蜂蜜）有這樣的非氧化型的抗菌活性。
    *術語“主動麥盧卡蜂蜜”，是為區別麥盧卡蜂蜜這種非氧化型抗菌活性的什麼被出售的麥盧卡蜂蜜不具備這一活動。這個詞在使用了自1998年以來，在出版物。
    *令人不解的是現在有出售的蜂蜜為“主動麥盧卡蜂蜜”，即賣方是指抗菌活性是由於過氧化氫，就像在所有其他類型的蜂蜜，而不是非氧化型的抗菌活性是獨特的麥盧卡蜂蜜和jellybush蜂蜜。
    *我們的研究，調查麥盧卡蜂蜜收集了不少網站大面積新西蘭，顯示水平的非氧化抗菌活性麥盧卡蜂蜜在一定程度上取決於對多種麥盧卡蜂蜜是收集，但主要的比例麥盧卡花蜜的蜂蜜。
    *蜂蜜出售麥盧卡蜂蜜不具有可衡量的一級非氧化抗菌活性，因而很可能已經生產主要來自蜜源植物以外的麥盧卡。
    *重要的是，非氧化型抗菌活性麥盧卡蜂蜜不會影響過氧化氫酶存在於人體組織和血清。這種酶會分解，在很大的程度，過氧化氫是主要的抗菌因子，在其他類型的蜂蜜。 （見附圖 1所示。）如果沒有非蜂蜜過氧化抗菌活性fpund只有在麥盧卡蜂蜜和蜂蜜jellybush被用於治療感染，效用的蜂蜜的抗菌活性極有可能減少，因為該行動的過氧化氫酶。
    *這種酶產生過氧化氫時被破壞蜂蜜蜂蜜暴露在光和熱。但是，非氧化抗菌活性麥盧卡蜂蜜是穩定的，所以沒有真正的主動關注麥盧卡蜂蜜失去活性存儲。
    *這種酶產生過氧化氫在蜂蜜變得活躍，只有蜂蜜稀釋。但是，非抗菌活性氧化滿員是在未經稀釋的麥盧卡蜂蜜，這將提供一個更強大的抗菌作用的深度傳播到受感染的組織。 （見附圖 2所示。）
    *這種酶產生過氧化氫在蜂蜜需要的氧氣可供反應，因此可能無法在傷口敷料或傷口洞穴或在腸道。主動麥盧卡蜂蜜，其中載有非氧化抗菌活性，是活躍於所有情況。
    *這種酶產生過氧化氫成為活躍在蜂蜜只有在酸性的蜂蜜是通過體液瓦解，但隨後稀釋的蜂蜜。
    *這種酶產生過氧化氫是無效的蜂蜜在酸性胃。
    *這種酶產生過氧化氫在蜂蜜可以摧毀蛋白消化酶在傷口的液體。
    *非抗菌活性氧化活性麥盧卡蜂蜜擴散更深入皮膚組織比過氧化氫是否從其他類型的蜂蜜。
    *活躍麥盧卡蜂蜜，其非氧化，抗菌活性，效果優於蜂蜜過氧化氫對某些類型的細菌。例如，它的兩倍左右有效，其他蜂蜜對 Eschericihia大腸桿菌和腸球菌，常見原因是感染傷口。這是更有效的比其他蜂蜜對幽門螺旋桿菌，為共同的事業消化性潰瘍。

效用的非抗菌活性氧化活性麥盧卡蜂蜜是衡量一個試驗開發的蜂蜜研究組：

          Ø的殺傷力蜂蜜樣品進行測試，最常見的傷口感染細菌的種類，金黃色葡萄球菌。
          Ø這是與該解決方案的一個標準防腐劑，苯酚（又稱石炭酸）在不同濃度。 （見附圖 3所示。）
          Ø這是通過添加過氧化氫酶的樣本，使所有蜂蜜過氧化氫被破壞，因此，只有非氧化抗菌活性麥盧卡蜂蜜被認為是。
          Ø非氧化抗菌活性麥盧卡蜂蜜，然後報告為當量濃度的酚具有相同水平的抗菌活性。 （例如，主動麥盧卡蜂蜜評為 10的非抗菌活性氧化會殺死金黃色葡萄球菌。黃色葡萄球菌，有效地將 10％的苯酚溶液。）

      這種抗菌活性測定，最近有其準確性提高，改進方法，將用於認證的懷卡托大學的評級的非抗菌活性氧化活性的罐子的麥盧卡蜂蜜被廣泛出售。 （見等級的抗菌活性麥盧卡蜂蜜詳情這種發展。）

      許多醫務人員正在使用Active麥盧卡蜂蜜（真正的排序） - 並獲得優異成績的患者感染的傷口尚未答复任何標準治療，如抗生素。對於大多數的各種品牌的註冊醫生蜂蜜產品的基礎上，所賣出的傷口處理和眼科的製造商選擇使用活動麥盧卡蜂蜜（同等級的活動範圍從 12至18）。

      都不是臨床上取得的成果是應該考慮的證據表明主動麥盧卡蜂蜜是比其他更有效的蜂蜜 - 一個比較的臨床試驗將需要確定。然而，也有良好的理論理由選擇使用Active麥盧卡蜂蜜良好水平的非抗菌活性氧化管理的傷口感染。

      為了減輕任何關切可能出現的風險引進感染使用的未加工的天然產品的傷口，我們調查的方法對消毒蜂蜜沒有任何損失的抗菌活性。我們發現，蜂蜜可以通過伽瑪輻射消毒不喪失活性。主動麥盧卡蜂蜜，純蜂蜜和製造的傷口敷料，是市面上這種方式消毒。 （見 http://bio.waikato.ac.nz/honey/where.shtml。）

       

      圖片 1：過氧化氫分解迅速（以氧氣和水）時，暴露在活性酶的過氧化氫酶存在於一小一滴血就豎起手指。

       

      圖片 2：蜂蜜示範工作敷料在受感染的傷口。更衣室材料浸漬麥盧卡蜂蜜或蜂蜜與三葉草，每個蜂蜜具有相同水平的抗菌活性測定的標準實驗室總抗菌活性。瓊脂種子已與金黃色葡萄球菌，其中增長形成明顯的殖民地時，板孵育。

       

      圖片 3：測量的效用的抗菌活性蜂蜜的解決方案，以及對標準防腐苯酚，已被擺在井削減在平板前盤的培養。瓊脂種子已與金黃色葡萄球菌，其中增長形成明顯的殖民地時，板孵育。該細菌並不生長在特定區域，抗菌活性擴散到瓊脂內的水井。