The manuka prescription

IT’S HARD TO IMAGINE THAT DEATH CAN RESULT FROM A SCRATCH. BUT UNLESS THE WORLD FINDS ALTERNATIVES TO TRADITIONAL ANTIBIOTICS, A MINOR INJURY MAY AGAIN PROVE FATAL. NOW SCIENTISTS ARE FINDING HOPE IN THE BACTERIA-FIGHTING POTENTIAL OF THE HUMBLE MĀNUKA TR

THE FIRST CIVILIAN to owe their life to the world’s earliest antibiotic, penicillin, was 33-year-old Anne Miller. It was March 1942, and Anne had been in Connecticut’s New Haven Hospital for a month, lingering close to death after she developed streptococcal septicaemia following a miscarriage — a not uncommon occurrence at the time.

Penicillin was still a rare, costly, and experimental medicine, but her doctor found a 5.5-gramme sample and administered it via IV. Incredibly, it broke her fever and, overnight, began clearing the infection. Anne died in 1999 at the age of 90, having made medical history and, in the process, changing the world forever. She was the first. But who will be the last?

Dying from an infection after a miscarriage — or pneumonia, tuberculosis, gonorrhoea, or a scratch — may once again be a reality as antimicrobial resistance (AMR) becomes more significant in homes and hospitals. AMR happens when bacteria develop resistance to the antibiotics that once killed them (bacteria reproduce so fast that it occurs very quickly on a human time scale). So-called multidrug-resistant organisms or “superbugs” are the result, infections that are impervious to treatment with current antibiotics.

There aren’t many new antibiotics on the horizon, but the humble mānuka tree may be able to help in the future. Māori used the tree in rongoā (traditional medicine) for thousands of years, and its beneficial effects are now so well known that the price of mānuka honey, for example, has skyrocketed, with the industry developing all the hallmarks of a gold rush.

Science goes some way towards backing up the mānuka hype. Global research shows promising antibacterial, anti-fungal, anti-inflammatory, and antioxidant properties. Mānuka extracts have been shown to combat antibiotic-resistant strains of infections such as MRSA (methicillinresistant Staphylococcus aureus).

Most recently, in a July paper published by the journal Food & Function, Aotearoa scientists outlined how mānuka honey may “train” immune cells, helping them respond to bacterial infections. Previous research has shown how the honey’s main antibacterial compound, MGO, works to disrupt bacteria. But in this new study, scientists from the Malaghan Institute of Medical Research found that, in the lab at least, methylglyoxal (MGO) from mānuka honey can also improve the cellular process that allows immune T cells to sense microbes. The researchers speculated that mānuka honey could enhance microbial sensing by the immune system, but say it needs further work in humans to confirm. Antimicrobial resistance is indeed a “global slow-moving catastrophe”, Mānuka Bioscience co-director and chemist Dr Suki Harding says. But she adds that mānuka oil, which

the company uses to make cosmeceuticals and medical applications, is “like a magical potion”. The miserable condition of impetigo/ school sores, for example, are caused by Staphylococcus aureus, which has a high level of antibiotic resistance and can also cause potentially life-threatening conditions, such as infections of surgical wounds and devices such as pacemakers, heart valves, catheters, and joint replacements. Harding says antibiotic-containing topical applications for skin conditions such as school sores have helped contribute to AMR.

“What’s happening now is that the more serious formulations, such as oral and intravenous forms, stop working because the bacteria have become resistant, and when you get serious infections and need serious forms of the drug, they don’t work anymore.”

Mānuka oil, however, can combat skin infections such as these. Because the oil contains hundreds of compounds when combined with other essential oils of high efficacy, the chance of bacteria developing resistance is reasonably low.

This means the potential of mānuka is not only crucial for medical and health reasons, but the sky’s the limit in terms of boosting the East Cape’s economy in the future. Harding’s company will invest in further clinical trials later this year, building on decades of global and New Zealand work investigating the plant - and centuries of traditional use before that.

“Gathering proper data on mānuka oil, how it functions, and the action mechanisms at work is how you can increase the value of mānuka oil from the East Cape region.

“Mānuka has been known and used for thousands of years; Māori people used all parts of mānuka for so many centuries. So it’s nothing new, but it’s really good to know what’s causing these amazing properties.”

‘There aren't many new antibiotics on the horizon, but the humble mānuka tree may be able to help... Research shows promising antibacterial, anti-fungal, anti-inflammatory, and antioxidant properties'

Dr Suki Harding.

Not all mānuka trees are created equally; the composition of mānuka oil from New Zealand plants is highly variable, and some have better therapeutic properties than others. The triketone concentration, in particular, is commercially valuable for its antimicrobial effect, and Harding says the best comes from trees found only in the East Cape region. A 2004 paper investigating mānuka essential oils found that trees from this area have a triketone content greater than 20 per cent, with little seasonal variation, which accounts for its outstanding antibacterial, antiviral and antifungal properties. Much of the mānuka found in other parts of New Zealand, particularly in the lower North and South Island, have triketone levels less than five per cent. And mānuka chemotypes grown in Australia have very low triketone levels. “Next to zero,” Harding says.