Effective Uses of New Zealand Native Plants in Clinic

Posted: August 2021
Author: Phil Rasmussen |  M.Pharm., M.P.S., Dip. Herb. Med.; M.N.I.M.H.(UK),  F.N.Z.A.M.H. 
 

In a world where an increasing number of plant species are under threat of extinction due to over-harvesting, loss of habitat or climate change, here in New Zealand we are very fortunate to have a diverse range of over 2200 different species of native plants, seaweeds, lichens and fungi. A large percentage of these probably possess valuable therapeutic properties, some of which we know about through traditional use in Rongoā Māori and by early European settlers, others through research or modern day usage by practitioners.

One of the goals when Phytomed was founded, was to educate and try to encourage the effective and sustainable use of New Zealand native plant medicines through the clinical practices of medical herbalists in New Zealand and Australia. This began with a review of Mānuka that I wrote for the first issue of Phytonews, the newsletter that accompanied the notification to New Zealand practitioners of Phytomed’s creation⁽¹⁾. I was convinced then as I am even more so today, that the Mānuka I grew up with on the East Coast of Aotearoa, is much, much more than a source of firewood, honey or essential oil.

For a better and healthier future, the guardianship and sustainability elements of Kaitiakitanga are paramount. Each of us should take responsibility to care for all elements of our natural environment, including to help foster the reinstatement of more of a native plant-based ecosystem, and incorporate more locally grown plants into our clinical practices.

Since we launched the first range of New Zealand native plant extracts for practitioner use in 1998, we’ve incorporated several of these in our Kiwiherb product range, so that more people can benefit from their unique properties. Through this and the large amount of practitioner use and patient outcomes we’ve observed over the past 23 years, we’ve learnt a whole lot more about their clinical applications.

A large amount of anecdotal information and case studies are now available, and I’ve given many seminar and webinar presentations into different possible applications of some of our native plants in New Zealand, Australia, Hong Kong and the U.K. These include New Zealand natives for First Aid conditions, for gastrointestinal conditions, for respiratory tract conditions, for skin conditions, and some with potential anti-cancer activities^(2-9). Like many of our herbs, most New Zealand native plants have not yet been well researched in a clinical situation. However, as we medical herbalists know, they still work very well when prescribed and dispensed in certain forms and doses, for a very wide range of clinical conditions!

Getting to know our natives:

Hearing and reading about specific herbal medicines is very interesting, and can really wet our appetites, but there’s no substitute for actually using them in clinical practice.  Starting to use even one or two species on ourselves, our partners, friends and family, is one of the best ways to learn about herbal medicine in our clinics. In fact, it’s this ‘getting to know the medicine’ (and thus the plant, its unique characteristics, and taonga), and our relationship with it, that as with traditional Rongoā Māori, is a key component of becoming an effective prescriber of New Zealand native plant medicines in clinical practice.

Mānuka

A good one to start with, Mānuka is endemic throughout most of the country, and we are rarely far away from a living source of this wonderful medicine, useful as a topical first aid or handy treatment for all manner of skin conditions including cuts, grazes and sores^(1,10). While other natives such as Tanekeha, Akeake and Koromiko can also help, Mānuka also makes a great astringent and tonic for diarrhoea and tummy upsets. The richness and diversity of the community of endophytes that live symbiotically with this classical NZ native plant, speaks of its versatility and many hidden treasures of relevance  to human and environmental health⁽¹¹⁾ .

Kawakawa:

This is another native readily available to most of us. The leaves of Kawakawa should be your go-to for patients with digestive conditions characterised by bloating or cramping, and for those with headaches or dysmenorrhoea. When taken in doses of one to two strong cups of tea or 5-15mls of a 1:2 hydroethanolic liquid extract, I know of nothing better to provide relief to a large proportion of patients suffering from these symptoms. Additionally, Kawakawa can be used topically for insect bites and inflammatory skin conditions, making this herb a true powerhouse of medicinal properties!

Akeake

While information on traditional Māori usage of this is relatively limited, there’s an increasingly large amount of information on Dodonaea viscosa emerging from research offshore. This supports not only its well-known application for upper respiratory tract infections, but also potential applications in prediabetic conditions, as it reduces blood glucose and improves glucose tolerance, serum insulin, and lipid profiles in rats⁽¹²⁾. Other studies show anti-candida and hepatoprotective activities, suggesting we should be using leaf extracts of this well-researched herb for a wider range of different clinical applications.

Hoheria:

A fairly common, and easy to grow native tree that I often use as an alternative to Marshmallow. Useful in children’s cough mixtures due to its sweet taste. It also combines well with Akeake and Meadowsweet for those with dyspepsia who want to wean off or avoid omeprazole.

Kumerahou

A highly respected (and rightly so) treasured herb from Ngāpuhi and Tamaki Makaurau territory. There’s now numerous case reports of patients with severe bronchial infections returning to good health following administration of Kumerahou. Due to its acrid and distinctive taste, remember to incorporate some liquorice or rehmannia with it to improve patient compliance.

Karamu

Karamu is another generally easy to source Coprosma species that has diverse indications. These include urinary tract conditions, stomach aches, colds and coughs, though doses need to be relatively large, and it works best when part of a team or formula with other specific herbs.

Poroporo

Poroporo is a fast-growing native plant sometimes seen as a weed by farmers, that I regard as one of the best topical treatments for pruritic skin conditions. Sorry to those who love chickweed more, but I’ve found it to be superior for most patients in my clinical practice.

Finally:

We all live in different locations and our ability to access living forms of New Zealand native plants and sustainably harvest these will vary. While I don’t have Horopito growing anywhere in my locality for instance, I still have the utmost respect and regard for it in clinical practice. I think it does great things to our gut microbiome and overall digestion, is a wonderful treatment for stomach ache, and is far more than an anti-candida agent⁽¹³⁾.

I’ve learnt as much from growing or wildcrafting plants as I have from teachers and books, and the same applies to growing then harvesting many native plants and utilising them as medicines. Since becoming fascinated with them as a child and starting to use some such as Mānuka and Kawakawa on myself as a student of herbal medicine, I’ve gained a lot more confidence with how to use them, and for what conditions. Like most of us on a daily basis, I’m often drawn to my favourites on my dispensary shelves. Somehow with them being more and more in my world and mind as I’ve grown older, I’m finally starting to feel that I’ve got to know some of our indigenous plants pretty well. I’d encourage you to do the same, perhaps through selecting 2-4 only initially, and through using them on yourself, your friends and family, and of course your patients. This will embark you on a journey of discovering their multiple medicinal properties and healing powers.

Even if it’s simply recommending Kawakawa tea for digestive or menstrual pain or headaches, or Akeake or Hoheria as an alternative to antacids or omeprazole, the number of common human health conditions that we now know to be very amenable to treatment with New Zealand native plants, is very encouraging.

Ngā mihi nui,

Phil Rasmussen

References:

1. Rasmussen PL, Herbal Monograph - Manuka. Phytonews 1, published by Phytomed Medicinal Herbs Ltd,,ISSN 1775-0251.  Auckland, New Zealand, Sept 1998.
2. Rasmussen PL. Treating digestive conditions using NZ native plants. Phytomed seminar, October 2009.
3. Rasmussen PL. NZ Natives for First Aid, Phytomed webinar, November 2013.
4. Rasmussen PL. NZ Native plants and their clinical applications for respiratory conditions, Phytomed Seminar, June 2015.
5. Rasmussen PL. Kumerahou – a Review. Phytonews 2, published by Phytomed Medicinal Herbs Ltd,,ISSN 1775-0251.  Auckland, New Zealand, 1999.
6. Rasmussen PL, Kawakawa – a Review. Pharmacy Today, August 2021.
7. Rasmussen, P.L. New Zealand Native Herbs (part 1): Phytomed Webinar, Apr 2018.
8. Rasmussen, P.L. New Zealand Native Herbs (part 2): Phytomed Webinar, Oct 2018.
9. Rasmussen, P.L. New Zealand Native Herbs (part 3): Phytomed Webinar, Nov 2019.
10. Mathew C, Tesfaye W, Rasmussen P, et al. Mānuka Oil-A Review of Antimicrobial and Other Medicinal Properties. Pharmaceuticals (Basel). 2020 Oct 26;13(11):343. doi: 10.3390/ph13110343. PMID: 33114724; PMCID: PMC7694078.
11. Rasmussen PL, Antimicrobial endophytes in Echinacea, Olive and Manuka. www.herbblurb.com  May 11, 2017.
12. Veerapur VP, Prabhakar KR, Kandadi MR et al. Antidiabetic effect of Dodonaea viscosa aerial parts in high fat diet and low dose streptozotocin-induced type 2 diabetic rats: a mechanistic approach. Pharm Biol. 2010 Oct;48(10):1137-48. doi: 10.3109/13880200903527736. PMID: 20815701.
13. Rasmussen PL. Pseudowintera spp (Horopito): a monograph. Australian Journal of Herbal Medicine, N.H.A.A., ISSN 1033 8330. 2014. 26(4): 150-154.