Tag: biodiversity

Mānuka & Kānuka industry and research Hui

On By philrasmIn UncategorizedLeave a comment

In recent months I’ve been fortunate to attend two Hui (gatherings), involving researchers, industry and iwi representatives, focussed on two important native plants here in Aotearoa New Zealand, Mānuka (Leptospermum scoparium) & Kānuka (Kunzea ericoides).

Mānuka Hui

In June a two day Bioeconomy Science Institute (BSI) Maiangi Taiao Mānuka Hui attended by around 50 people was held at the Plant and Food (now Bioscience Research Institute) premises in Palmerston North. This was an inspiring event which brought together representatives of Māori groups and industry, with researchers from across all four of the previous Crown Research Institutes (CRI’s) and Callaghan Innovation, now combined into the new Bioeconomy Science Institute (BSI, or Maiangi Taiao. A handful of us had also taken part also in two previous hui on ‘Manuka and More’, held in 2016 in Ruatoria and Te Araroa on the east coast of New Zealand’s north island (Tairawhiti), which I wrote about at the time(1). 

Over the two day meeting, there were around 20 short presentations by researchers, industry and iwi representatives on some of the work done in recent years, involving our treasured native plant, Leptospermum scoparium (Mānuka).  It’s impossible to adequately summarise these presentations here, but quite a range of research projects have taken place or started within the past nine years. Much of this involves Mānuka Honey, given how important this industry  is now to many regions of Aotearoa, and how it was the first to put Mānuka on the global map(2).

Kānuka and Mānuka are the dominant native woody species forming early-successional vegetation on formerly forested sites in lowland New Zealand. Their importance as pioneer species has been shown by studies showing that species richness or subsequent biodiversity, was much better in areas where Kānuka and Mānuka were the initial prevalent species(3). A collaboration between Comvita and scientists from the Bioeconomy Science Institute has also demonstrated that planting Mānuka forests on former high-country marginal grazing land can significantly restore biodiversity in as little as five years(4).

The Mānuka honey industry went through a lengthy period of rapid growth in demand and hive numbers over several years prior to 2019. This became unsustainable however, and a range of factors lead to challenging times since then, with registered hive numbers falling sharply from a peak of 918,000 in 2019 to less than 490,000 in 2026. When I wrote about the 2016 Hui, hive numbers were around 350,000(1).

A great deal of evidence however, now suggests much rosier times lie ahead for the Mānuka honey industry. I’ve researched and written four review articles on the science behind this honey over the past 20 months, and the sheer volume and diversity of compelling research findings supporting its many health promoting and medicinal applications, is very encouraging(2, 5, 6, 7).

Jackie Evans and John Oliver from Comvita discussed work their company has been doing on the compound lepteridine, found only in Mānuka honey, recently shown to inhibit enzymes involved in gastrointestinal inflammation(8). A clinical trial involving lepteridine-standardized mānuka honey for the treatment of functional dyspepsia, is currently underway(9).

My talk was entitled “Mānuka – from Plant to Product”, and I spoke about my experience since 1998 with formulating and developing various herbal medicines for internal and topical use containing Mānuka honey, Mānuka oil, dried foliage, and hydroethanolic extracts. In this I incorporated some key issues to consider, when wanting to successfully develop and commercialise health products made using native plants.

Many other interesting presentations were made, including ongoing work into characterising the different genotypes within Mānuka, and methods to ensure better authenticity of Mānuka honey, and to distinguish it from Australian Leptospermum species. The need to preserve and protect mātauranga Māori (traditional Māori knowledge) and taonga species such as Mānuka through placing high value on the interweaving of relationships between people, places and the environment, was also a prominent theme throughout the hui.

A presentation by Grant Smith from the BSI was rather sobering though, as he discussed the continued advance of myrtle rust as a devastating pathogen on several of our other native Myrtaceae species such as ramarama and swamp maire. While others such as Mānuka, Kānuka, Pōhutukawa and rātā have yet to be seriously impacted, the damage this pathogenic fungus has caused to many native bush stands in parts of Australia, and increasing influence of extreme weather events and global warming, suggests a growing threat also to some of our iconic indigenous species(10). The work being done here on identifying mechanisms and genes associated with resistant varieties, may also help our Australian neighbours to better manage their own myrtle rust outbreaks.

At the start of the hui, David Chagne, Jenny Green and Nico Bordes gave an overview of the newly established BSI. Bringing the former CRI’s together again into a combined entity as the primary government agency involved in scientific and industrial research aimed at supporting the growth and resilience of the bioeconomy of New Zealand, makes absolute sense in my view.

Launch of the Bioeconomy Science Institute

Establishment and development of the Biodiscovery Platform, a $42 million government investment to support the development of high-value products and innovation over the next 7 years, was also discussed. This identified the shared sectors direction to build impactful fundable pathways, incorporating a fit for purpose, Treaty-based approach(11). The Biodiscovery Platform is in the process of setting priorities and exploring possible research partnerships. A key objective as a sector enabler is to invest in activities that bring groups together, and to establish clear, repeatable pathways for research into our native plants and their bioactivities and possible commercialisation pathways.

Kānuka Hui

A couple of months later in August, an inaugural hui dedicated to Kānuka (Kunzea ericoides), another highly endemic native species to Aotearoa, was put on by the Kānuka Charitable Trust (KCT), with support from the BSI. The Kānuka Charitable Trust was established in 2023 by a group of Māori landowners and business leaders to protect Kānuka as a taonga species and ensure Māori values guide the development of an emerging Kānuka industry, with Manu Caddie and Richard Manning as founding directors(12).

The hui was facilitated mostly by Nikki Harcourt and Manu Caddie, and attended by landowners, growers, essential oil producers, scientists and researchers and a range of people working with kanuka in their various companies and industries. While as with Mānuka these have to date been based almost entirely on essential oil and honey production, potential applications for other types of products or uses of this botanically related native tree, were discussed.

While ten years ago very little attention was given to Kānuka, it is an important species in forest regeneration. It has been widely planted on erosion-prone land, supports carbon sequestration, encourages biodiversity in flora and fauna, and contributes to rural employment.

Like its botanically related cousin Mānuka, it also possesses many medicinal properties. Traditional applications include for wounds and inflammatory skin conditions, and for several conditions affecting the digestive tract(13). 

Research within the last few years has shown antibacterial and antifungal activities for Kānuka oil against a range of organisms, including Propionibacterium acnes, and MRSA(14).  Its chemistry and relative bioactivities are variable depending on the location, season and extraction methods, but α-pinene is generally the most abundant compound.

Favourable results were reported from a 2022 clinical trial involving application of a 3% kānuka oil cream for eczema, funded by Hikurangi Bioactives, Honeylab and Callaghan Innovation(15). However, challenges have been encountered with commercialising this product in export markets, including unanticipated regulatory barriers in relation to being able to make therapeutic claims.

Authenticity work

Given some of the mistakes made by the Mānuka honey industry in the past, efforts to establish product authenticity are vital for the future Kānuka industry, in order to ensure product is true to label and to protect its market value and supplier reputation.

Much good work has been done and is underway in this area, particularly that by Nigel Perry from Plant & Food Research, on the phytochemistry and potential markers in Kānuka oil(16). David Speed from ALS Analytica, summarised ongoing studies into identification and characterisation of novel constituents of Kānuka, and distinguishing this from Australian Kunzea species. The monoterpene compound α-pinene is generally most prevalent in Kānuka oil, rather than the β-triketones characteristic of good quality Mānuka oil.

A talk by Sri Govindaraju of PAQ Laboratories, which provides specialist testing techniques to support the local honey industry, described how they have developed an assay method for Kānuka honey, and definitions for multifloral or monofloral honey. Currently a lot of blending of different honey suppliers is occurring, with the true volume of Kānuka honey being produced, is not being captured. The last two years had also seen low yields for Kānuka honey supplies, due to heavy rainfall during the short harvest season.

Kānuka honey was found to contain relatively high amounts of type-2 arabinogalactan proteins, which may contribute to immunostimulant and immunomodulatory properties(17).

Being able to further utilise natural waste products or normally discarded plant parts after harvest or extraction of their most desirable components, and fostering a more sustainable and circular economy, makes absolute sense in the world we live in today.  During extraction of the essential oil of Kānuka, large volumes of hydrosols, or aqueous preparations infused with mostly water soluble plant compounds, are produced. These also have many potential applications in human and animal health. Christel Brunschwig from the BSI discussed research into valorising the spent brush not only into hydrosols, but also as a potential biofuel source or feedstock for other types of processing or production operations.

Karl Fraser and Melissa Savage discussed work they are doing on environmental influences on Kānuka oil production, and an ecologist Meg Gray summarised the impact of cyclones, goats and deer grazing, and water quality, on the quality of a Kānuka forest. Pest control is now recognised as being crucial to avoid forest stagnation and loss of biodiversity, as well as the ability of a Kānuka forest to capture carbon.

Lessons learnt

I spoke about some of the lessons learnt from the Mānuka industry to date, and from my previous NHP industry experiences, including the hurdles and steps required to obtain product licences in Australia, and the importance of having a product development and commercialisation strategy that was fit for purpose. My talk also mentioned the importance of understanding regulatory requirements, as all too often these are not well considered, prior to investment in research and product commercialisation.

Another key message we heard at the hui, was that while stories concerning Kaupapa Māori and traditional knowledge are compelling and can support a global marketing strategy for products made from native plants, these need to be supported by collectivism, and consistency. Given the struggle that native plant based industries and companies in Aotearoa have had to date with attaining good and ongoing growth, yet beckoning and growing market opportunities in many overseas markets, this warrants much more consideration by some elements within the broader sector. In order to succeed with the sustainable, ethical and quality based commercialisation of natural health products manufactured using these indigenous plants, it is critical that producers of Mānuka and Kānuka work collectively to develop and support industry standards, certification, and consistent and adequately resourced research and marketing efforts.

References:

  1. Rasmussen PL. Mānuka and More. www.herbblurb.com November 18, 2016.
  2. Rasmussen PL. Mānuka and other Honeys – exciting recent research. www.herbblurb.com November 30, 2024.
  3. Sullivan Jon J, Williams Peter A, Timmins SM. (2007) Secondary forest succession differs through naturalised gorse and native kānuka near Wellington and Nelson. New Zealand Journal of Ecology 31(1): 22 – 38©New Zealand Ecological Society.
  4. https://www.bioeconomyscience.co.nz/news-and-events/news/2026-news/biodiversity-benefits-of-large-scale-manuka-forest-planting
  5. Rasmussen PL, Manuka honey as a medicine. New Zealand Doctor, 15 February 2025. ISSN
  6. Rasmussen PL. Honey as a medicine: Special properties of mānuka honey. Pharmacy Today, 1 October 2024, published by The Health Media Ltd, Auckland, ISSN 1170-1927.
  7. Rasmussen PL. Mānuka honey shows promise in cancer prevention and as treatment adjunct. 1 December 2024, published by The Health Media Ltd, Auckland, ISSN 1170-1927.
  8. Lin B, Nair S, Fellner DMJ, Nasef NA et al, The Leptospermum scoparium (Mānuka)-Specific Nectar and Honey Compound 3,6,7-Trimethyllumazine (LepteridineTM) That Inhibits Matrix Metalloproteinase 9 (MMP-9) Activity. Foods. 2023 Nov 9;12(22):4072. 
  9. Ombasa L, Miller J, Ware L, Abbotts-Holmes H et al, Impact of Mānuka Honey on Symptoms and Quality of Life in Individuals With Functional Dyspepsia: Protocol for a Feasibility Randomized Controlled Trial. JMIR Res Protoc. 2025 May 21;14:e66417.
  10. Rasmussen PL. Mānuka and Myrtle Rust. www.herbblurb.com July 19, 2017.
  11. https://www.mbie.govt.nz/about/news/government-launches-biodiscovery-platform-to-grow-new-zealands-bioeconomy.
  12. https://www.hakanuka.co.nz/
  13. Rasmussen PL, Kānuka & Inflammation. Phytomed Medicinal Herbs Ltd, Dec 2022. https://www.phytomed.co.nz/blogs/phytobrief/kanuka-inflammation.
  14. Haira TH, Ooi RJ, Pay RA, Paenga B, Caddie M, Skinner D, Harcourt N, Jackson M, Keyzers RA, Munkacsi AB. Antimicrobial-guided metabolomic analysis of essential oil derived from the Aotearoa New Zealand endemic plant Kunzea robusta (Kānuka). Fitoterapia. 2025 Jul;184:106592.
  15. Shortt N, Martin A, Kerse K, Shortt G et al, Medical Research Institute of New Zealand’s Pharmacy Research Network. Efficacy of a 3% Kānuka oil cream for the treatment of moderate-to-severe eczema: A single blind randomised vehicle-controlled trial. EClinicalMedicine. 2022 Jul 15;51:101561.
  16. Perry N. Kanuka oil: current knowledge and potential markers. Plant & Food Research Dunedin, October 2022

Mānuka and Myrtle Rust

On By HerbBlurbIn Antifungal, Biosecurity, Environment, Herbal Medicine, Manuka, Myrtle Rust, Organic Medicine, Pathogen, Plant MedicineLeave a comment

Last week I attended a two day workshop organised by scientists at Plant and Food Research Ltd and Massey University in Palmerston North, to discuss a range of recent scientific and biosecurity developments, concerning Mānuka (Leptospermum scoparium), an important plant in New Zealand’s natural environment and economy. As with the two day Hui on ‘Mānuka and More’ in Ruatoria and Te Araroa in November last year, this was an excellent event in which more than 30 scientists working actively on Mānuka research presented on a diverse range of subjects and discussed where there could be gaps in our knowledge or research needs for this plant. While Mānuka Honey and essential oil are currently the main two medicinal products produced from Mānuka, numerous other therapeutic applications and potential contributions to preserving our environment, are found within this plant.

Jacqui Horswell and colleagues from the Institute of Environmental Science and Research, have shown that Mānuka and other myrtaceaeous plants seem to be capable of killing the faecal bacterial pathogen Enterobacter coli (E. coli), by enhancing the die-off of this and other pathogenic organisms that pass through their root systems. A field trial involving riparian planting of Mānuka is just getting going, to see whether laboratory results extend to helping to reduce animal effluent flows into a polluted lake. A lake which was once pristine and a treasured swimming area, but in recent years has changed into a green and dirty waterway due largely to dairy industry runoff, has been selected for this trial.

Hayley Ridgway from Lincoln University presented some interesting findings concerning novel and potentially useful mycorrhizae (fungi) and endophytic bacteria associated with the roots of Mānuka, some of which I wrote about in my previous blog. Inoculation of Mānuka plants with different mycorrhizae causes significant alterations in their growth rates and essential oil composition, highlighting the complex inter-relationships between microbes associated with Mānuka, and its production of phytochemicals including some with bioactive properties.

Other presentations were made on experiences to date involving plantations of Mānuka which have been established at a number of North Island sites in recent years. Challenges include site access, weeds, pests, and the relative attractiveness of different genetic lines to bees. A comment made by one of the presenters that while humans have had multiple generations of experience with cultivation and enhancing performance characteristics of crops such as wheat and rice, our experience with Mānuka plantations spans less than 10-15 years to date.

The hottest topic at the workshop, however, was the recent finding of isolated outbreaks of Myrtle Rust (Austropuccinia psidii) in New Zealand nursery and garden grown specimens of Mānuka and the native tree, Ramarama (Lophomyrtus bullata). This pathogenic fungi originated from Brazil where it causes guava rust, but spread internationally into North America in the 1880’s, and was first reported in Australia in 2010.  Australia is home to around half of the world’s Myrtaceae (Myrtle family) plant species, including Eucalyptus (850 species), Melaleuca (176 species) and Callistemon species.

Outbreak of Myrtle rust has had a devastating effect on much of the east coast as well as other areas of Australia, where it has resulted in ecosystem collapse for certain plant species. To date it has only been found in isolated locations in Northland, Waikato, Bay of Plenty and Taranaki, although it is widespread on Raoul Island in the Kermadec group, about 1,100km to the north-east of New Zealand.

Myrtle rust spores can easily spread across large distances by wind, or via insects, birds, people, or machinery, and it is thought the fungus arrived in New Zealand carried by strong winds and significant weather events from Australia.

The Myrtle Rust Strategic Science Advisory Group is working hard to assess and try to ameliorate the widespread environmental, economic, social and cultural impacts this plant pathogen could have on New Zealand. Apart from Mānuka and Ramarama, other indigenous Myrtaceae species such as Pohutakawa (Metrosideros spp) and Swamp Maire (Syzygium maire), are under risk. Priorities including acceleration of scientific research into the biology of the pandemic strain detected here, pathways of spread, surveillance, management, exploring plant susceptibility and resistance, and coordinating and communicating a management plan that has widespread engagement by communities, scientists, industry and Maori stakeholders and landowners, councils and government.

The Ministry for Primary Industries (MPI) and the Department of Conservation (DOC), with the help of local iwi, the nursery industry, and local authorities are running an operation to determine the scale of the situation and to try and contain and control myrtle rust in the areas it has been found. However, emergence of the infection and appearance of the distinctive yellow or brown leaf discolouration may not become fully apparent until the spring, and a better assessment of the number of infection sites and their extent, may not be possible until then.

The arrival of Myrtle Rust in New Zealand means that the task of collecting and storing seed of New Zealand indigenous Myrtaceae including Mānuka, has now become urgent. The NZ Indigenous Flora Seed Bank (NZIFSB), a collaborative project between Massey University, AgResearch, Landcare and the Department of Conservation, with support from the NZ Plant Conservation Network and the Millennium Seedbank at Kew in the UK, was established in 2013. NZFISB has been doing some really valuable work to collect and store seeds aimed at preserving a wide range of biodiversity within New Zealand native plant species. More than 130 volunteer seed collectors have been trained to date, and plans are underway to extend this and the level of community participation, to try to better protect our native plants for generations to come.

Refs:

http://www.nzpcn.org.nz/page.aspx?conservation_seedbank

http://www.mpi.govt.nz/protection-and-response/responding/alerts/myrtle-rust/