ribwortRibwort (narrow leaved plantain) is commonly seen in pastures, lawns and street verges, and once positively identified, is rarely forgotten. One of the most useful and endemic “weeds”, its young fresh leaves have been used for centuries as a healing ointment and treatment for slow healing wounds, bites and haemorrhoids, by people from many different parts of the world.

Seed husks of its botanical relative Plantago ovata (commonly known as Psyllium seed), are used as a bulking laxative and for digestive health.

The other main application of Ribwort leaves, is to improve the health and function of the mucous membranes in the respiratory tract. A particular characteristic of this plant, when harvested and prepared in the optimal way, and applied or taken in sufficient doses, is its gentle nurturing and nutritive, but also protective barrier effects on delicate mucous membranes of the nasal passage and other sensitive skin areas of the body. These mucous membranes help protect the sinuses and bronchial tract from invading micro-organisms and other insults, and foods and herbs that optimise their function, can help protect against and manage a wide range of upper respiratory tract conditions.

The diverse phytochemistry of ribwort, which includes polysaccharide hydrocolloids (mucilaginous compounds), phenylethinoid glycosides, flavonoids, coumarins, cinnamic and other phenolic acids, contributes to its anti-inflammatory, antioxidant and antimicrobial activities. This combination of herbal actions makes it a valuable addition to the treatment of inflamed sinuses, catarrh or blocked noses. Research has also found ribwort in large doses to be comparable or superior to the drugs ranitidine and misopristol, in an animal model of peptic ulcer (1).


Human influences on the health of this plant

As a common and fairly fast growing plant, ribwort is one of a number of plant species being studied by plant and environmental scientists, for the effects of pollutants on its health and physiology. Recent studies have found ribwort grown near mines, smelting plants and other contaminated areas, accumulates high levels of cadmium, lead and other heavy metals(2-4). Heavy metal contamination of ribwort, dandelion and birch growing in urban areas of Poland with considerable air and soil pollution, has also been shown to be high(5).

In animal farming, anthelmintics (anti-worming drugs) are regularly applied to control gastrointestinal nematodes, and these are excreted from animals into pastures and the wider environment. Along with other drugs such as antibiotics, anthelmintics have become one of a new class of micro-pollutants that disturb the environment. The anthelmintic drugs albenazole, flubendazole and flenbendazole for example, widely used in conventional animal farming, are taken up by and metabolised by ribwort. However, they also produce, in the plant, a significant increase in concentrations of proline (a well-known stress marker), and activities of several antioxidant enzymes. This suggests a possible risk of oxidative damage in this and other plants influenced by these drugs, and is a growing cause of concern(6,7).

Anthelmintic drugs excreted into pastures and taken up by plants also have the potential to impede seed germination negatively, thus affecting affect the regeneration of ribwort and other plants(8).

These studies reinforce the sensitivity of ribwort and other plants to environmental contaminants as a result of human activity, in this case mining, city air pollution, and conventional animal farming. As we are only beginning to discover such delicate links between environmental pollutants and plant health, the importance of growing this plant (and probably numerous others) in certified organic soil as opposed to purchasing it from non-organic, so-called ‘wildcrafted’ or trade broker sources, is highlighted.


  1. Melese E et al. Evaluation of the antipeptic ulcer activity of the leaf extract of Plantago lanceolata L. in rodents. Phytother Res. 2011 Aug;25(8):1174-80. doi: 10.1002/ptr.3411. Epub 2011 Feb 7.
  2. Tamás J, Kovács A.Vegetation pattern and heavy metal accumulation at a mine tailing at Gyöngyösoroszi, hungary. Z Naturforsch C. 2005 Mar-Apr;60(3-4):362-7.
  3. Tinkov AA et al. Comparative Analysis of the Trace Element Content of the Leaves and Roots of Three Plantago Species. Biol Trace Elem Res. 2016 Sep;173(1):225-30.
  4. Drava G et al.Trace elements in Plantago lanceolata L., a plant used for herbal and food preparations: new data and literature review. Environ Sci Pollut Res Int. 2019 Jan;26(3):2305-2313.
  5. Nadgórska-Socha A. Air pollution tolerance index and heavy metal bioaccumulation in selected plant species from urban biotopes. Chemosphere. 2017 Sep;183:471-482.
  6. Stuchlíková Raisová L et al. Evaluation of drug uptake and deactivation in plant: Fate of albendazole in ribwort plantain (Plantago lanceolata) cells and regenerants. Ecotoxicol Environ Saf. 2017 Jul;141:37-42.
  7. Stuchlíková LR et al, Biotransformation of flubendazole and fenbendazole and their effects in the ribwort plantain (Plantago lanceolata). Ecotoxicol Environ Saf. 2018 Jan;147:681-687.
  8. Eichberg C et al. The Anthelmintic Ingredient Moxidectin Negatively Affects Seed Germination of Three Temperate Grassland Species. PLoS One. 2016 Nov 15;11(11): e0166366. doi: 10.1371/journal.pone.0166366. eCollection 2016.

Honeysuckle and other useful weeds surrounding us

In taking my usual summer holiday in rural New Zealand this year, I noticed that over the past year, certain ‘noxious weeds’ seem to have grown more prolific.
While perhaps I shouldn’t focus on such observations when I’m meant to be resting and indulging in leisure pursuits, I’m frequently alarmed at the disconnect between people and plants in their environment. This is especially obvious at this time of year, for two highly medicinal particular species, Chinese Privet (Ligustrum lucidum) and Japanese Honeysuckle (Lonicera japonica).

In January and February the distinctive creamy-white flowers of Chinese Privet trees make their presence obvious in many towns and rural locations and increasingly in areas of native bush. While the flowers are attractive and from a distance somewhat similar to the European Elder (Sambucus nigra), the berries produced are a delicacy to birds, who have successfully spread it throughout the land to make it the most noxious tree in the country. Similarly the smaller but scented flowers of the vigorous climber Japanese Honeysuckle, which open white then turn lemon-yellow, draw my attention to how successful this plant has been in establishing itself in more rural, native bush and farm environments.

Our avian relatives seem to have more incentives than simply having a feed for finding the berries and seeds of these two plants so desirable, as in traditional Chinese and Asian medicine both plants have been common medicines for centuries.

In Asia, Japanese Honeysuckle is traditionally used for febrile illnesses featuring fever, headache, coughs, thirst & sore throat. It is also widely used as an anti-bacterial, anti-inflammatory, antiviral and anti-diabetic agent, and is used topically for skin infections and sores, ulcers, carbuncles, swollen joints and rheumatic conditions.

A recent study found that unripe fruit from Japanese honeysuckle has strong antioxidant properties which contribute to animal health(1). Another study found that extracts improved age-related physiological functions and extended the life expectancy of worms by 22%(2).

Bacteriostatic (antibacterial) effects have been shown against Staphylococcus aureus and Escherichia coli for an ethanolic extract of Japanese honeysuckle leaves(3). In mice with sepsis (a serious bacterial infection of the blood), an ethanol extract of Japanese honeysuckle flower buds enhanced bacterial clearance, reduced the level of sepsis and risk of multiple organ failure, resulting in a lower rate of sepsis-induced mortality (4). This suggests potential applications as a good adjunct with or alternative to antibiotics. With growing concerns around antibiotic resistance, these findings should enhance our interest in this plant, now endemic throughout New Zealand.

Diabetes is another traditional use of Japanese honeysuckle, and researchers in Taiwan have found an ethanol extract of flowering aerial parts to reduce diabetic nephropathy in rats. Japanese honeysuckle treatment to diabetic rats for 8 weeks reversed three key abnormalities associated with renal dysfunction – including reduced creatinine clearance, increased blood urea and proteinuria, and an elevated ratio of kidney weight to body weight(5).

Anti neurodegenerative compounds with monoamine oxidase B receptor affinity (identified as isochlorogenic acid A and isochlorogenic acid), have also recently been detected in Japanese honeysuckle flowers(6). In Korean traditional medicine this plant has been used for cancer management, and anticancer activities on human lung cancer cells have recently been documented for polyphenol compounds extracted from it(7).

I’ve discussed the many medicinal benefits of Chinese Privet fruits in my March 2016 blog, particularly in relation to their potential prophylactic and treatment benefits for degenerative bone and joint conditions such as osteoporosis and arthritis(8). Again, a great deal of research has validated these and other therapeutic actions. Other recent findings include possible benefits of a combination of Chinese Privet and Siberian ginseng (Eleutherococcus (Acanthopanax) senticosus), to protect against bone marrow suppression induced by chemotherapy in mice(9). Inhibitory effects against the influenza A virus have also been reported for secoiridoid components of Privet fruits(10), and compounds with neuraminidase inhibitory activity (a key mechanism of action of anti-influenza drugs), have been isolated from its leaves(11).

Knowledge of these many useful potential medicinal applications for these two plants, should be of great interest both to those wanting cost-effective local solutions to increasing health concerns, as well as those concerned at the damaging effects that they are starting to have as invasive species, on our ecosystem and native species habitats.
The effect of invasive plants on natural ecosystems can be disastrous, firstly for the competition with indigenous species, and secondly, because they limit the stability and availability of natural resources to the whole native species community. They constitute a global environmental, economic, and social change driver as they can dramatically alter the composition of ecosystems and lead to losses in biodiversity, agriculture productivity, and human health. These negative effects of invasive plant species are likely to be exacerbated by climate change, which will foster their further spread especially in valuable fertile areas.
Identifying innovative ways for communities to transform invasive plants from ‘problems to resources’, represents an important challenge for modern societies and policy makers. Bioprospecting and investigating both Lonicera japonica and Ligustrum lucidum to identify and develop new phytomedicines and compounds to promote human health in the future, is surely worth further exploration and research.


ligustrum jan19
Ligustrum lucidum Jan19


1. Guzzetti L et al, Scientific Reports 7:13799, 2017.
2. Yang ZZ Free Radic Biol Med. 2018 Dec;129:310-322.
3. Xiong J et al, Food Chem. 2013 May 1;138(1):327-33
4. Kim SJ et al, J Ethnopharmacol. 2015 Aug 2;171:231-9.
5. Tzeng TF et al, Planta Med. 2014 Feb;80(2-3):121-9.
6. Wu GF et al. J Sep Sci. 2019 Jan 17. doi: 10.1002/jssc.201801255. [Epub ahead of print].
7. Park C, Phytother Res. 2018 Mar;32(3):504-513.
8. Chen B et al, 2017 Molecules. 2017 Sep 5;22(9).
9. Wang C et al, Biomed Pharmacother 2019 Jan;109:2062-2069.
10. Pang X et al, Bioorg Med Chem Lett 2018 May 15;28(9):1516-1519
11. Zhang Y et al, J Chromatogr B Analyt Technol Biomed Life Sci 2018 Apr 15;1083:102-109.



New Zealand is often seen as a ‘clean and green’ country with levels of pollution much lower than those in the rest of the world, but recent research by Auckland Council has revealed that levels of air pollution in Queen Street (Auckland’s main street) are in fact rising. According to the research, Queen Street levels of black carbon, which are ultra-fine carbon particles emitted to the air and formed through the incomplete combustion of fossil fuels, biofuels and biomass, are more than three times higher than in Canadian cities and two times higher than concentrations in major cities in Europe and the U.S.(1).

Like other forms of fine airborne particulate matter (PM10 particles), black carbon can enter deep into the lungs, and travel into the bloodstream to become deposited into tissues such as the brain or heart. Both short- and long-term exposure is linked with serious health effects. Epidemiological studies have shown an increase in morbidity and mortality rates from chronic obstructive pulmonary disease after exposure to elevated levels of air pollution, and associations between lung cancer and cardiovascular diseases are well established(2, 3). Exposure to traffic related particulate matter is also increasingly associated with an increased risk of birth defects, and Alzheimer’s disease and other dementias in later life(4, 5).

Black carbon also contributes to a warming effect on our climate(6, 7), and to the melting of snow and glaciers(8). Genotoxic and other damaging effects on plants, are also evident as a result of particulate matter pollutants(9).

The biggest source of high levels of black carbon in the council Queen St study was identified as diesel emissions from older buses, trucks, ferries and ships. While replacing diesel buses with electric buses, introducing modern electric trams and pedestrianising Queen Street in the future would reduce black carbon, the currently very high levels of exposure to pedestrians and others working in or visiting the area or similar inner city locations in other cities, are of concern. Similarly high black carbon levels in other New Zealand cities, towns and locations, have been shown to be unacceptably high(10-11).

In Asian cities it is a common sight to see locals wearing a mask to protect their lungs against the damaging effects of vehicle, smoke or factory pollution and so-called toxic smog. Good quality masks provide some form of a physical barrier to filter out some of these harmful airborne particles, but wearing them can be cumbersome.

It is appropriate also, to consider the potential support that certain medicinal plants can provide to lung health, when there is exposure to a high level of airborne pollution. In cities such as Beijing, Delhi and Mexico City, high levels of air pollution have increased demand for herbal products that enhance lung function, and may help protect against some of the numerous damaging health effects that particulate matter and other airborne pollutants can have.

As written about in February 2016 after my visit to Singapore, there are many herbs traditionally used for lung conditions and upper respiratory tract infections, which seem to work at least partially through gently encouraging the natural expectoration process of the millions of cilia cells lining our bronchial trees. The role of these is to remove excess mucus and potentially harmful substances such as particulate matter or unwanted allergens, so enhancing their ability to fulfill this protective function, can be useful. Mucilaginous (polysaccharide hydrocolloid rich) and expectorant herbs such as marshmallow (Althaea officinalis), mullein (Verbascum thapsus) and the NZ native hoheria (Hoheria populnea), seem to work in this manner. Other traditional lung herbs such as elecampane (Inula helenium), white horehound (Marrubium vulgare) and horseradish (Armoracia rusticana), can also be helpful.

In Britain the root of elecampane was traditionally prepared into a candy as a protection against ‘bad air’, and research now suggests this volatile oil and sesquiterpene lactone rich plant may help protect against some of the more serious potential outcomes of exposure to high levels of airborne pollutants.

Increasing data is emerging on potential cancer protective effects of elecampane, and separate research teams have found it to inhibit the growth of a range of different types of human cancer cell lines in vitro, yet not damage normal cells(12, 13). Potential antitumour activity for elecampane extracts against certain forms of brain cancer, has also been reported(14).

Horseradish is a popular European plant whose root has been used not only to make a hot sauce, but also as a traditionally used warming expectorant and lung tonic. It contains phytochemicals which are well absorbed orally and have established chemo-preventive effects. Anti-mutagenic properties and protective effects against DNA damage shown by horseradish(15) are also of interest, as DNA damage prevention is an important mechanism involved in cancer prevention by dietary compounds.

To summarise, efforts should continue to reduce the sources of black carbon and other forms of airborne pollution. However, chemo-preventive or protective effects shown by various herbal extracts against cellular damage and carcinogenicity may be helpful when exposure to air pollution is unavoidable. Inhalation or ingestion of these in appropriate concentrations at or soon after the time of exposure, may impart short term resistance against the many damaging effects of airborne pollutants, and should be further explored.

1. ‘Toxic Air Threat’. New Zealand Herald, Nov 7 2018. http://www.nzherald.co.nz
World Health Organisation, Health risks of particulate matter from long-range transboundary
air pollution, 2006. http://www.euro.who.int/__data/assets/pdf_file/0006/78657/E88189.pdf
2. Segersson D et al, Int J Environ Res Public Health. 2017 Jul; 14(7): 742. Published online 2017 Jul 7.
3. Kilian J, Kitazawa M, Biomed J. 2018 Jun;41(3):141-162. doi: 10.1016/j.bj.2018.06.001. Epub 2018 Jul 17.
4. Wang L et al, J Public Health (Oxf). 2018 Aug 18. doi: 10.1093/pubmed/fdy137. [Epub ahead of print]
5. Bond TC, Sun H. Environ Sci Technol. 2005 Aug 15;39(16):5921-6.
6. Ramanathan V et al, Nature. 2007 Aug 2;448(7153):575-8.
7. Painter TH et al, Proc Natl Acad Sci U S A. 2013 Sep 17;110(38):15216-21
Rai PK, Ecotoxicol Environ Saf. 2016 Jul;129:120-36
8. Davy PK, & Trompetter WJ (2018a). Black carbon in New Zealand. GNS Science, Lower Hutt.
9. Davy, PK, & Trompetter, WJ (2018b). Heavy metals, black carbon and natural sources of particulate matter in New Zealand. GNS Science, Lower Hutt.
12. Dorn DC et al, Phytotherapy Res, Aug 16 (epub ahead of print), 2006.
13. Spiridonov NA et al, Phytotherapy Res 19(5): 428-432, 2005.
14. Koc K et al, J Cancer Res Ther. 2018 Apr-Jun;14(3):658-661
15. Gafrikova M et al, Molecules. 2014 Mar 14;19( 3):3160-72.


Overcoming Insomnia – Drug versus Herbal Solutions

So-called “Z drugs” such as zopiclone, were first approved as prescription sleeping tablets in the U.S. in 1993, and these are now more often used for insomnia than benzodiazepines such as Valium® (diazepam) or Mogadon® (nitrazepam)(5). However, whether these newer generation drugs which seem to act on different sites of the same GABA-A receptors as benzodiazepines, are in fact safer than their older cousins, is debatable. While their shorter duration of action and different receptor affinities may be associated with a slightly lower risk of dependency, they seem to be just as likely to lead to motor vehicle accidents & falls leading to fractures, particularly in older adults. These are major adverse events associated with the use of these drugs, and together with the risk of dependency, remain real concerns especially with ongoing use. Their prolonged use in young adults, can also compromise cognition, and have other negative adverse events in this age group. Finally, a range of other rare but serious adverse events from Z- drugs have been implicated in recent years, including dementia, infections, respiratory disease exacerbation and pancreatitis(6).

While the once widespread use of strong sedative antihistamine drugs to help knock out infants and children at night seems to have dissipated in recent years, other pharmaceutical drugs apart from benzodiazepines and Z drugs, are still widely used for stress management and associated sleeping difficulties. These include some powerful prescription-only drugs such as antipsychotics, antihistamines and opiates, which in many countries now, are being taken for sleep disorders and related ‘off label’ indications, and not just for their approved uses.

A cross-sectional study in 2015 also revealed that 42% of patients in the community taking a benzodiazepine or zopiclone for insomnia had experienced at least one adverse event, 52% had tried to stop, and that 23% of those taking Z drugs, wanted to stop taking the drug.

Given all of this, it is hardly surprising that many look for a herbal alternative to assist them to nod off and sleep soundly at night. However, while there seems to be a huge array of products out there said to help, including a large array of herbal teas with sleep-invoking names and packaging, when it comes to clinical trials showing that these actually work, there doesn’t seem to be a whole lot of compelling evidence.

A review of clinical trials of herbal products for insomnia, published in the December 2015 journal Sleep Medicine Reviews, evaluated 14 randomised clinical trials involving a total of 1602 participants with insomnia(7). The authors concluded that very few of these trials showed improved sleep quality and duration following herbal interventions. Of relevance perhaps, was that virtually all trials involved the use of herb combinations rather than individual agents. However, as is the case with such trials, the quality of the products involved, and doses used, varied enormously.

One of the best known herbs used traditionally for insomnia, is Valerian (Valeriana officinalis) root. While there has been a mixed appreciation of its value in recent years, and its taste and odour aren’t exactly pleasant, comments from the esteemed German medical practitioner and phytotherapist Rudolf Weiss, who widely prescribed Valerian and other herbs while in Russian captivity with limited drug supplies during World War 2, are salient:

“Valerian is beyond doubt a good and genuine sedative. There is however one aspect that has often been neglected: to be properly effective, valerian has to be prescribed in a sufficiently high dosage. It is almost pointless to give ten or twenty drops of valerian tincture; any effect here would be largely psychotherapy. The dose has to be very much larger, at least a whole teaspoonful of the tincture in water or on sugar…..the single dose of one teaspoonful may, if necessary, be repeated two or three times at short intervals. The greater effectiveness of some proprietary valerian preparations is due to the fact that this has been taken into account, with the dosage made sufficiently high”(8).

Medical conditions or other physical ailments, can also be partly or largely contributory to a poor night’s sleep, and identifying and trying to manage these with appropriate herbal medicines, can also be worthwhile. These include menopause, depression, aches and pains due to arthritis or injury, migraines, alcohol or drug withdrawal, or adverse effects to drugs such as prednisone or methamphetamine.

Clinical trials have shown Valerian and a combination of Valerian with Lemon Balm to improve the quality of sleep in postmenopausal women(9,10). Valerian with acupressure also improved the quantity and quality of sleep in patients with acute coronary syndrome(11). Another trial found Valerian to improve sleep in HIV patients taking the antiviral drug efavirenz(12), and a combination of Valerian, Hops and Zizyphus, to improve both total sleep time and night awakenings frequency(13).

There is in fact much more in the way of good quality published research supporting the benefits of herbal interventions in cases of anxiety or associated conditions, than straight insomnia. Evidence from clinical trials and other studies of anxiolytic as opposed to sedative effects for various medicinal herbs, is already substantive, and growing. As discussed in my February 2017 blog, there are many herbs which have been successfully traditionally used for anxiety. They include Chamomile, Lavender, Skullcap, Passionflower, Valerian, Kava, Lemon balm, Zizyphus, Hops and Withania.

Extracts of the Polynesian plant Kava (Piper methysticum) became popular towards the end of last century, for the management of anxiety disorders and related insomnia. While product type and phytochemistry, and doses used in clinical trials have been highly variable, a clear benefit has been shown in most cases.

Taking adequate doses of these anxiolytic herbs can certainly help promote a better quality sleep, and provide some relief to debilitating insomnia. Most anxiolytic drugs and sedative drugs work on the same GABA receptors, and it is not surprising that the same mode of action probably applies also to herbal medicines. By acting to help ease tension, anxiety and stress, they can effectively address some of the underlying and contributory factors to lack of sleep.

It is clear that more clinical studies to better determine efficacious herbal medicines and optimal doses, are sorely needed for the management of sleep disorders. However, their ability to help prevent insomnia, or avoid the need to take pharmaceutical drugs with a relatively high risk of adverse events, is well established. It is this ability of herbal medicines when properly selected and prescribed to address more than the outcome of a long-standing or acute underlying imbalance in health, but rather to help rebalance overall health and overcome weaknesses in several contributory areas, that makes them such excellent prophylactics. And after all, a prophylactic is preferable to a sticking plaster, especially one that is prone to fall off or leak when left on too long.


1. Sleep Disorders and Sleep Deprivation: An Unmet Public Health Problem. Institute of Medicine (US) Committee on Sleep Medicine and Research; Colten HR, Altevogt BM, editors. Washington (DC): National Academies Press (US); 2006. The National Academies Collection: Reports funded by National Institutes of Health.
2. Brzecka A et al, Front Neurosci. 2018 May 31;12:330.
3. Zitting KM Sci Rep. 2018 Jul 23;8(1):11052
4. Bordoloi M, Ramtekkar U. Med Sci (Basel) 2018 Sep 14;6(3).
5. Pollmann AS et al. BMC Pharmacology and Toxicology 2015; 16:19.
6. Brandt J et al, Drugs RD 2017 Dec;17(4):493-507.
7. Leach MJ, Page AT, Sleep Med Rev 2015;24:1-12.
8. Weiss Rudolf Fritz Lehrbuch der Phytotherapie (Herbal Medicine): Published by Hippokrates Verlag, Stuttgart, Germany, 1960. English edition first published 1988.
9. Taavoni S et al, Menopause. 2011 Sep;18(9):951-5
10. Taavoni S et al, Complement Ther Clin Pract. 2013 Nov;19(4):193-6.
11. Bagheri-Nesami M. J Tradit Complement Med. 2015 Jan 31;5(4):241-7
12. Ahmada M et al, Ann Pharmacother. 2017 Jun;51(6):457-464
13. Palmiera G, Nat Sci Sleep. 2017 May 26;9:163-169

Echinacea – a useful herb for allergies

The best known use for the root of Echinacea (also known as Purple Coneflower), is the prevention or treatment of upper respiratory tract infections, such as influenza and the common cold, and its pharmacological activity is often simplified down to being regarded as an ‘immuno-stimulant’.

A close look at the traditional applications for Echinacea however, suggest its most prominent uses were to reduce inflammation. The traditional uses by North America Indians and early European settlers, included inflammatory conditions such as snake bites, sore throats, swollen gums and abscesses, and other conditions where a high level of localised or systemic inflammation is characteristic. Much of Echinacea’s established pharmacology therefore also relates to an anti-inflammatory mode of action, with tongue-tingling alkylamides being the key active phytochemicals (1, 2).

Inflammation is also a major component of many allergic and autoimmune conditions, including asthma, hay fever or systemic lupus erythematosus. Anti-inflammatory drugs such as prednisone, beclomethasone and flumethasone are frequently prescribed to reduce the symptoms of these. The concept of Echinacea being used for such conditions can be hard to grasp, particularly when influential texts such as the German ‘The Complete Commission E Monographs’, the European Pharmacopoeia and websites presenting information on medicinal herbs, make statements such as:

“Because of its immunostimulating activity, Echinacea must not be used in cases of progressive systemic disorders (tuberculosis, sarcoidosis), autoimmune diseases (e.g.: collagenoses, multiple sclerosis), immunodeficiencies (e.g.: HIV infection; AIDS), immunosuppression (e.g.: oncological cytostatic therapy; history of organ or bone marrow transplant), diseases of the white blood cell system (e.g.: agranulocytosis, leukemias) and allergic diathesis (e.g.: urticaria, atopic dermatitis, asthma).

Despite such statements, there is in fact no substantiated evidence of Echinaceas absolute contraindication in any of the above immunological or autoimmune conditions, making this precautionary statement a potential theoretical, rather than clinically proven one.

Something else that European regulators are overly sensitive about is the likelihood of Echinacea triggering allergic reactions, to the point of advising against its use in children under the age of 12. The background to this however, is likely attributable to the greater prevalence in Europe of products containing either the whole plant or flowering tops of Echinacea, rather than just the root. Using just the root is more often seen in Australia, New Zealand and North America. Products made using flowering Echinacea tops contain higher pollen levels, and are therefore more likely to be associated with allergic reactions in atopic subjects, as seems to have been the case in Europe(3).

Further insight into whether Echinacea is or isn’t safe to use in autoimmune conditions, was provided by a recent American study which investigated its effects on mast cells(4).  Mast cells are a type of white blood cell and known to be important mediators of allergic and inflammatory responses. Upon exposure to an allergen and release of immunoglobulin E (IgE) antibodies, an influx of calcium occurs resulting in mast cell degranulation and the release of inflammatory mediators such as histamine, leukotrienes, and other pro-inflammatory cytokines. These actively contribute to allergic reactions and the subsequent inflammatory response, including those seen in asthma and allergic rhinitis (hay fever). The main mechanism of drugs such as sodium cromoglycate, used as an inhalation for hay fever and asthma, is to reduce mast cell release of histamine and other inflammatory mediators.

Effects of an ethanolic extract of Echinacea purpurea root were evaluated on mast cell degranulation, calcium influx, cytokine and lipid mediator production, using both bone marrow derived mast cells and a rat basophilic leukemia mast cell lines. As well as the crude Echinacea root extract, a purified alkylamide (dodeca-2E,4E-dienoic acid isobutylamide), and fractions containing both low and high alkylamide levels, were also tested for effects on mast cell function.

The Echinacea extract and isolated dodeca-2E,4E-dienoic acid isobutylamide, inhibited degranulation from both mast cell types after treatment with a calcium ionophore, as well as after stimulation with IgE. Histamine release from the rat basophilic leukaemia mast cell lines, was reduced by 47%, and that of TNF-alpha and prostaglandin E2 (PGE2), but by a lesser degree. Inhibition of calcium influx by Echinacea and its alkylamides, was implicated as a mechanism of action, and as similar actions were shown also on non-mast cells, other possible pharmacological actions of benefit in both inflammatory and autoimmune conditions, are likely.

Inhibition of mast cell degranulation and calcium influx was observed by Echinacea purpurea extracts and Echinacea fractions with high alkylamide content, but not by fractions with little to no detectable alkylamide levels. This implicates alkylamides in the anti-allergic actions of Echinacea purpurea root extract, and adds to the large existing body of evidence that they contribute significantly to the overall immunomodulatory and anti-inflammatory actions of this plant.

The combined effects of Echinacea purpurea on mast cell activation, considered together with research showing it reduces the release of inflammatory cytokines from macrophages, suggests the possible application of high alkylamide-containing Echinacea purpurea extracts for limiting inflammation associated with allergic responses, in addition to that associated with infections.

Further evidence of Echinacea’s anti-allergic effects was provided recently from results of a study by Hungarian and German researchers, who found an alkylamide-rich Echinacea extract to exert strong anti-inflammatory effects and help restore the epidermal lipid barrier, in patients with atopic (allergic) eczema. Topical application of an Echinacea cream, reduced both pruritis (itchiness) and redness in an 85 day clinical trial involving patients with atopic eczema, particularly from days 57 to 85(5).


  1. Rasmussen PL, Phytonews 14 , Evaluation of anti-inflammatory effects of Echinacea purpurea and Hypericum perforatum, ISSN 1175-0251, published by Phytomed Medicinal Herbs Ltd, Auckland, New Zealand, Dec 2002
  2. Rasmussen PL, Phytonews 24 , Effects of Echinacea on virus-induced respiratory cytokines, ISSN 1175-0251, published by Phytomed Medicinal Herbs Ltd, Auckland, New Zealand, Feb 2006
  3. Rasmussen PL, Phytonews 38 , Safety of Echinacea in Children, ISSN 1175-0251, published by Phytomed Medicinal Herbs Ltd, Auckland, New Zealand, Dec 2012
  4. Gulledge TV, Mast cell degranulation and calcium influx are inhibited by an Echinacea purpurea extract and the alkylamide dodeca-2E,4E-dienoic acid isobutylamide. J Ethnopharmacol. 2018 Feb 15;212:166-174.
  5. Oláh A et al, Echinacea purpurea-derived alkylamides exhibit potent anti-inflammatory effects and alleviate clinical symptoms of atopic eczema. J Dermatol Sci. 2017 Oct;88(1):67-77.


Medicinal Uses of Nasturtium

With spring upon us, the New Zealand countryside and our gardens are rich with budding and flowering plants, many of them normally regarded as weeds, but in fact highly medicinal.

One of these is Nasturtium (Tropaelum majus; Indian cress), a plant with water lily like circular leaves and bright yellow, orange and red flowers which is native to South America but established in many warmer areas of New Zealand and Australia. While it can certainly be very weedy in some situations, it also makes a useful plant on the edges of the vegetable garden to attract bees and other beneficial insects. It can also act as a decoy by attracting cabbage white butterflies and drawing these pests away from brassicas.

What many people don’t realise, however, is that all parts of Nasturtium are edible, with its leaves and flowers making a decorative, peppery addition to salads, and the fruits when pickled with vinegar serving as a tasty alternative to capers. It also has outstanding antioxidant activity due to its rich content of phenolic compounds, including anthocyanin and vitamin C. Like many ‘weeds’ readily available in the New Zealand environment, Nasturtium is also a highly medicinal plant.

Traditionally it was used to help ward off and treat various infections, particularly those affecting the lungs and the urinary tract. The pungent compounds known as isothiocyanates found in all parts of nasturtium and roots of horseradish (Armoracia rusticana), have powerful and fairly broad spectrum antibacterial activities particularly against Haemophilus influenza and Moraxella catarrhalis, a common cause of middle ear infection (otitis media) and sinusitus in children(1). These isothiocyanates have also recently been reported to have good activity against both developing and mature biofilms of Pseudomonas aeruginosa, a bacterial pathogen associated with many serious human illnesses(2). Importantly also, they have also been shown to be well absorbed into the bloodstream following oral ingestion of nasturtium in humans(3).

Nasturtium was used in folk medicine as a remedy against scurvy, and can be used as a natural, warming remedy to help the body overcome and prevent the common cold and influenza. It was also used traditionally to treat muscular pain, and it’s antimicrobial properties extend to its use as a topical treatment for bacterial infections and minor scrapes and cuts.

Possible applications in the prevention or treatment of various cancers are also likely, due to conversion of a key constituent glucotropaeolin to benzyl isothiocyanate, within the body. This compound, formed also from isothiocyanates found in brassica (cruciferous) vegetables, exhibits anticancer activity against cultured lung, breast, liver, prostate, brain, melanoma, oral & ovarian cancer cells in vitro, and prevents chemically induced carcinogenesis in rodents(4-10).

Potential benefits in fluid retention, hypertension and other cardiovascular conditions, have been suggested by Brazilian research showing diuretic, hypotensive and lipid-lowering activities for a hydroethanolic extract in rats(11-13). Angiotensin converting enzyme (ACE) inhibition was implicated as a possible mechanism for these effects, in a similar manner to how ACE inhibitor drugs work to help manage hypertension and other cardiovascular conditions(14). Unlike many other conventional diuretic drugs, however, no unwanted effects on urinary calcium or potassium excretion seem to occur, suggesting valuable potassium and calcium-sparing properties. These findings indicate possible applications also to help prevent osteoporosis, which is supported by another Brazilian study in menopausal rats(13).

Nasturtium may also be useful to help prevent or manage obesity, according to findings from a Korean study published in the June 2017 issue of the journal Food and Nutrition Research(15). The study investigated the effects of a nasturtium ethanolic extract on a mouse cell line with adipocyte-like characteristics, used in research on adipose (fat) tissue. Treatment of cells with nasturtium extract produced a concentration-dependent reduction in lipid accumulation, and inhibited the expression of various proteins associated with differentiation of fat cells. This suggests potential usefulness also, in the prevention and treatment of obesity.

With these compelling research findings, incorporation of nasturtium into the diet or herbal treatments of a range of human conditions common in the 21st century, should overtake our view of it simply as a bothersome weed.


  1. Conrad A et al, Drug Res (Stuttg). 2013 Feb;63(2):65-8.
  2. Kaiser SJ et al, 2017 Jun;119:57-63.
  3. PPlatz S et al, Mol Nutr Food Res. 2016 Mar;60(3):652-60..See comment in PubMed Commons below
  4. Wattenberg LW. J Natl Cancer 1977 Feb;58(2):395-8.
  5. Hecht SS et al. J Nutr. 1999 Mar;129(3):768S-774S.
  6. Cho HJ et al, Int J Mol Sci 2016 Feb 22; 17(2):264
  7. Shang HS et al, Environ Toxicol 2016 Dec; 31(12):1751-1760.
  8. Yeh YT et al. Food Chem Toxicol. 2016 Nov;97:336-345.
  9. Zhu M et al J Cancer. 2017 Jan 15;8(2):240-248.
  10. Lai KC et al, Int J Oncol. 2017 Sep;51(3):832-840.
  11. Gasparotto Junior A et al. J Ethnopharmacol. 2009 Apr 21;122(3):517-22.
  12. Gasparotto Junior A et al. J Ethnopharmacol. 2011 Mar 24;134(2):210-5.
  13. Barboza LN et al, Evid Based Complement Alternat Med 2014; 2014:958291.
  14. Gasparotto Junior A et al J Ethnopharmacol. 2011 Mar 24;134(2):363-72. (2011a)
  15. Kim GC et al,.Food Nutr Res. 2017 Jun 14;61(1):1339555.


Herbal Medicine Can Help Reduce High Demands on Hospitals

An article in yesterday’s New Zealand Herald , reports that Auckland City Hospital is struggling to cope with a huge increase in demand which has seen almost 200 people coming through the emergency department every day. This increase in patients (7% up on those treated at the same time last year) has also been experienced by a large number of hospitals throughout the country, at a time of year when the impact of seasonal illnesses such as influenza, has yet to manifest.

While New Zealand’s population growth is a contributory factor, A&E departments are seeing a higher proportion of sicker and older people than in the past, as well as chronic illnesses such as diabetes, heart disease and cancer that were less common in days gone by. Additionally, the impact of prolonged poverty and poor diets in too high a proportion of NZ’s population, continues to be avoidable catalysts to a need for emergency hospital services.

The fact that Auckland Hospital’s capacity has been in the high 90’s and has hit 100% a couple of times recently, combined with more and more seriously sick patients requiring treatment, is cause for alarm. Should an influenza epidemic or major disaster occur during the next few months, the ability for existing healthcare services to cope with the sudden increase in additional demand, is in serious doubt. Given the huge and growing pressures they are under, many nurses, doctors, and other healthcare professionals are already close to breaking point, and it is therefore, essential that we reflect upon how this unacceptable situation can be addressed.

Herbal Medicine (Phytotherapy) is the oldest and most used form of medicine in the world. While like most people I am extremely grateful to be living in an age where drugs such as antibiotics and modern medical interventions can treat conditions that once would have resulted in an early death, it is time for the potential contribution of plant-based medicine to human wellness and many common illnesses, to be better recognised.

Evidence for the therapeutic benefits of many herbs and plants incorporated into the diet or an overall treatment approach has increased exponentially in recent years, and to not take this evidence seriously, will be to our peril. A vast body of science suggests that a phenomenal number of plants can either enhance our resistance to and reduce our risks of a wide range of illnesses, or reduce our over-dependence on drug and hospital treatments.

While a large number and diverse array of herbal products are easily obtained from retail outlets or online from e-commerce sites, and many of these are appropriate to take for minor ailments or to help prevent illnesses such as headaches, stomach upsets, colds and the flu, other herbs and a more systematic treatment for more serious or chronic conditions, are best accessed through consulting a properly trained medical herbalist. Such practitioners in New Zealand generally spend 3 or 4 years in full-time training within accredited institutions to study physiology, anatomy, biochemistry, diagnosis and nutrition, and how to prescribe herbal medicines and avoid adverse herb-drug interactions, and most are professional members of the New Zealand Association of Medical Herbalists (NZAMH) . In the same way that we go to a cardiologist for a comprehensive check-up and full diagnosis before being prescribed medications for a heart condition, the professional medical herbalist should be regarded as the specialist we consult before taking herbs for any serious, chronic or debilitating illness.

Apart from their skills in prescribing effective herbal medicines, medical herbalists and naturopaths can make a significant contribution to encouraging healthier diets, lifestyles and other activities that could have a large impact on reducing the number of hospital admissions and pressure on A&E services.

Last week I gave a presentation to a Brisbane conference organised by the Naturopathic and Herbalists’ Association of Australia (NHAA), on the subject of Ginkgo, Ginger and Ginseng, and their use as adjunctive herbs alongside conventional medicine. These are just 3 herbs for which there is compelling evidence that taking them together with various drugs for conditions including dementia, schizophrenia, infectious disease and diabetes, is not only more effective, but can also reduce drug-related adverse effects, and have pharmacoeconomic benefits through reducing the dependence on costly conventional healthcare services. These are just the tip of the iceberg in what else we can achieve through proper and professionally supervised combinations of herbs with drugs, and more research funding and clinical trials are warranted.

As with all health professionals, however, regulation by government to ensure that an adequate standard of service is provided and that the practitioner works in a professional and ethical manner with his or her patient, is essential. The NZAMH is a body that recognised this need a long time ago, and first applied in 2007 for statutory regulation under the Health Practitioners’ Competence Assurance (HPCA) Act (legislation which regulates a number of different health practitioner professions). While this application was subsequently accepted by the then Minister of Health, Pete Hodgson, with a change in government and revision of the HPCA Act soon afterwards, NZAMH was told a new application was needed. A resubmitted application was made to the government in early 2015, but disappointingly, there seems to have been little progression of it since that time.

During World War 2, when New Zealand’s access to many drugs and conventional medicines was under threat, much ground-breaking and valuable research was undertaken into the phytochemistry and bioactivities of many of our indigenous flora and fauna. With our hospitals now close to bursting, not to mention an alarming global increase in antibiotic resistance, the time has now come for policy makers, health funding providers, other health professionals and politicians, to again cast their attention to the enormous contribution that herbal medicine can make to our current and future healthcare services.

Herbal Medicines: Organic Or Not?

I’ve heard much discussion lately about how important Organic certification is for herbal medicines, and feel it’s appropriate to contribute my 2 cents worth.

The Oxford Dictionary defines ‘Organic’ in relation to food or farming as being ”produced or involving production without the use of chemical fertilisers, pesticides, or other artificial chemicals”.  Most organic certification agencies today extend this definition to exclude products made involving genetic modification (GMO’s).

Echinacea bumble bee

Humans have applied natural compounds and simple chemicals such as copper sulphate and lime as pest control methods in agriculture for a long time, but the use of synthetic pesticides accelerated in the 1940’s with the development of organochlorines such as DDT, aldrin, dieldrin, chlordane, parathion, and 2,4-5-T. Usage of agrichemicals to improve productivity and profits has been the norm for most types of farming ever since. Today a whole host of different synthetic chemicals are used in modern horticulture, ranging from fertilisers to herbicides to fungicides to insecticides to plant growth regulators.

Widespread and global contamination of the environment with organochlorines has occurred, and pesticide residues are now detectable in virtually all wildlife, well water, food and in humans. The long term effects of such compounds on the environment as well as human and plant health are unknown, as are those of residues of chemicals such as antibiotics and bovine growth hormones found in consumer products such as meat or milk. What is known, is that pesticides can have significant chronic health effects, including but not limited to cancer, neurological effects, diabetes, respiratory diseases, fetal diseases, hormone disruption and genetic disorders.

biogro standard 2009Most medicinal herbs are grown in developing countries, where programmes to control exposures to agrichemicals are either limited or non-existent. Many agrichemicals are toxic to handle, and pose significant risks, particularly in the event of accidental spills or inhalations. Children are particularly vulnerable to their harmful effects, with even very low levels of exposure during development potentially having adverse health effects. The World Health Organisation estimates that there are 3 million cases of pesticide poisoning each year and up to 220,000 deaths, primarily in developing countries.

Apart from the direct impact on humans, insects or animals who consume plant extracts either as foods or medicines which contain synthetic and potentially harmful chemicals, the effects that usage of chemical agents in agriculture have on the health of the planet’s bees, soils, waterways, and air, are of great concern.

The impact of farming practices on soil health is poorly understood, although soil samples from conventional farming generally contain higher levels of organochlorine pesticide residues compared to organic farming(1). The importance to soil health of diversity within the bacterial and fungal communities living within the soil, is becoming increasingly recognised, and this is greater under fully organic crop management(2,3).

The link between neonicotinoid pesticides and Colony Collapse Disorder in bees has been acknowledged by regulators in many countries, but took many years to happen. Also they remain in widespread use in some countries, despite potentially posing a serious threat to the world’s bee population upon which much of agriculture is dependent.

Given these adverse effects, and the absence of long term data in support of many new compounds being 100% safe, it is little wonder that consumer appetite for the use of synthetic and chemical-based pesticides continues to wane. While to date this trend towards organics seems to mainly apply to foods, given that most users of herbal medicines are taking them to optimise their health including to help counteract the effects of harmful environmental exposures, it would seem highly appropriate for there to be a preference for certified organic rather than non-organic herbal remedies.



  1. Witczak A, Abdel-Gawad H. J Environ Sci Health B. 2012; 47(4):343-354.
  2. Reilly K et al, J Sci Food Agric 2013; 93(15):3700-9.
  3. Verbruggen E, Toby Kiers E. Evol Appl 2010; 3(5-6):547-560.

Farming plants rather than animals

My prime motivation in starting this blog, was and remains to espouse my enthusiasm for plants as medicines. However, some say food is the best form of medicine, and fruits, berries, vegetables and nuts (all from plants), are certainly healthy foods. Food availability and quality are also dependent on the condition of the soils and waterways where they are grown, as is human health related intrinsically to the health of the planet Earth.


In 2016, environmental sustainability and climate change are critical issues facing humankind. A recent study by a formidable team of scientists suggests the impact of global warming will be quicker and more catastrophic than generally envisaged(1). The environmental effects of human agriculture, which contribute more than a quarter of all greenhouse gas emissions, therefore warrant more debate.

Growing evidence highlights the likely dual health and environmental benefits of reducing the proportion of animal-sourced foods in our diets(2). Recent evidence from large prospective US and European cohort studies and meta-analyses of epidemiological studies, shows an association of long-term consumption of substantial meat and particularly processed meat, with an increased risk of total mortality, cardiovascular disease, colorectal cancer and type 2 diabetes(3,4 ,5).

Two modelling studies published recently by sustainability researchers at Oxford University, now provide a compelling case that reducing red meat intake could also dramatically reduce greenhouse gas emissions and the rate of climate change(6,7).

The Oxford researchers used a region-specific global health model to analyse the environmental and health impacts of four dietary scenarios in the year 2050. A reference scenario was developed based on current projections from the UN Food and Agriculture Organisation (FAO). The second scenario, assumed the implementation of global dietary guidelines on healthy eating (the healthy global diet), and that people consume just enough calories to maintain a healthy body weight. The healthy global diet included a daily intake of at least five portions of fruits and vegetables, less than 50g of sugar, a maximum of 43g of red meat, and an energy content of 2,200-2,300 kcal. Other scenarios also assumed a healthy energy intake but were based on diets that were vegetarian (six portions of fruit and vegetables) or vegan (seven portions of fruits and vegetables, and one portion of pulses). For the first time, the Oxford team also attempted to estimate the economic value of different dietary choices, through their effects on health and the environment.

For the health analysis, they built a comparative risk assessment model to estimate age and region-specific mortality associated with changes in dietary and weight-related risk factors known to influence mortality in a dose-related manner. For the environmental analysis, they linked regional and scenario-specific food type consumption levels to greenhouse gas emissions. The economic analysis placed a monetary value on changes in greenhouse gas emissions by using estimates of the social cost of carbon and explored monetizing the health consequences using the value of statistical life, and projections of health-care expenditure by cause of death.

The findings from this analysis were that by 2050 less than half of all global regions are projected to meet dietary recommendations for the consumption of fruit, vegetables and red meat, and would also exceed the optimal total energy intake. To achieve the healthy global diet scenario, a 25% increase in global fruit and vegetable consumption would be required, moreso in Sub-Suharan Africa and South Asia. Global red meat consumption would need to decrease by 56%, and in Western high-income and middle-income countries, by a staggering 78% and 69% respectively.

The modelling study shows that moving to diets with fewer animal-sourced foods would have major health benefits, and reduce global mortality by 6-10%. Compared to the reference scenario, the authors projected that adoption of the healthy global dietary guidelines would avoid 5.1 million deaths per year, the vegetarian diet 7.3 million deaths a year, and the vegan diet 8.1 million deaths a year. More than half of these avoided deaths would be attributable to decreased red meat consumption, with 23-35% to increased fruit and vegetable consumption, and 19-30% to less over-eating. Shifting diets toward more plant-based and less animal-based foods, could reduce global mortality by 6-10% and food-related greenhouse gas emissions by 29-70% compared with a reference scenario in 2050. These benefits were calculated to be achievable even without any allowance for the beneficial impacts of dietary change on land use through avoided deforestation, meaning the theoretical reduction in greenhouse gases could be even higher.

The monetized value of adoption of the healthy global diet would also be comparable with, or exceed, the value of the environmental benefits. Overall, the economic benefits of improving diets were estimated to be 1-31 trillion US dollars, which is equivalent to 0.4-13% of global gross domestic product (GDP) in 2050.

In New Zealand, our animal-based agricultural sector is responsible for the bulk of our greenhouse gas emissions.  An estimated 80% of agricultural emissions of greenhouse gas arise from the livestock sector, in particular from ruminants such as cattle. One cow’s annual output of methane is about 100kg, equivalent apparently to the emissions generated by a car burning 890 litres of petrol, each year.

With growing concerns about the economic viability of the dairy industry even without any allowance for the many negative and historically under-estimated environmental impacts of its intensive model(8), it is time for a serious re-evaluation of New Zealand’s current agricultural sector.

However, food is both emotional and political, especially in agriculturally based economies such as New Zealand, where many have an unquestioning belief that red meat is a necessary dietary component, and that ‘more is good’. The negative reaction from the North American Meat Institute to the Oxford studies, is about as predictable as that of the American Rifleman’s Association to every attempt made to tighten gun laws there. Proponents of a largely vegetarian-based diet tend to gain more airtime in the U.K., but this has undoubtedly been catalysed by the Thatcher era mad cow disease scare, and the subsequent foot and mouth outbreak in 2001.

These types of regional differences and ingrained dietary and farming practices, will be no easy task to change, a fact acknowledged by Springmann and others(6,9). Clearly, massive political, industrial and cultural changes would be required to produce a 25% increase in fruit and vegetable consumption and 56% less meat consumption on a global level. Nevertheless, with climate change and the growing toll of diet-related premature deaths reaching crisis levels, it is time to seriously digest the growing amount of compelling research supporting horticulture as the basis of both foods and medicines. What we eat greatly influences our personal health and the environment we all share, and growing plants rather than farming methane-producing animals is a powerful way to mitigate climate change and to prevent many deaths.


  1. Hansen James: https://www.aip.org/history/climate/impacts.htm
  2. Tilman D, Clark M Global diets link environmental sustainability and human health. Nature 2014; 515(7528):518-522.
  3. Battaglia Richi E et al, Health risks associated with meat consumption: A review of epidemiological studies. Int J Vitamin Nutr Res 2015; 85(1-2):70-78.
  4. Lippi G et al, Meat consumption and cancer risk: a critical review of published meta-analyses. Crit Rev Oncol Hematol 2016 Jan; 97:1-14.
  5. Wang X et al, Red and processed meat consumption and mortality: dose-response meta-analysis of prospective cohort studies. Public Health Nutr 2016 Apr; 19(5):893-905.
  6. Springmann M et al, Analysis and valuation of the health and climate change cobenefits of dietary change. Proc Natl Acad Sci USA 2016; Mar 21. pii:201523119 (epub ahead of print).
  7. Springmann M et al, Global and regional health effects of future food production under climate change: a modelling study. Lancet 2016 Mar 2. Pii:S0140-6736(15)01156-3.
  8. Foote KH et al, New Zealand Dairy Farming: Milking Our Environment for all its worth. Environ Manage 2015; 56(3):709-720.
  9. Marsh D. J Water resource management in New Zealand: jobs or algal blooms? Environ Manage 2012; 109:33-42.

Ligustrum lucidum – noxious weed or useful osteoporosis treatment?


It’s a Saturday in early February in NZ, and the warm summer days linger on. Trying to retain some of the holiday vibe, we pack a picnic and togs and head out with some friends to Cornwallis Beach, on Auckland’s west coast.

On the way, as we drive up through Glen Eden and Titirangi, I find it difficult not to comment on the frequent appearance of Glossy Privet (Ligustrum lucidum) trees, on road and garden verges including an alarming number of indentations into adjacent native bush. Prominent this time of year with their creamy-yellow flower clusters amidst a dark green foliage background, they remind me of the Elder trees whose flowers used to similarly draw my attention every summer when I lived in the UK.

Unlike Elder in the UK, however, Glossy Privet is not native to New Zealand, and just like hundreds of other clever plant species, has become so well colonised here it is classed as a ‘noxious’ plant. It is, in fact, according to the NZ Plant Conservation Network(1), New Zealand’s most invasive introduced tree, as the dark purple brown berries make a tasty treat for our large bird population who then excrete the seeds far and wide. Not only around Auckland, but on a drive back from Gisborne to Auckland in January, I again couldn’t help but notice the large number of these trees in numerous locations throughout the 500km journey.

While my frequent comments concerning this tree to family or other fellow passengers over the past couple of years may seem obsessive, my fascination with it stems from the fact that it is also highly medicinal. In its native China, the small fruits of Glossy Privet (Nu-Zhen-Zi) are commonly used to strengthen bones, and it is an ingredient of many herbal formulae for the treatment of osteoporosis.  Osteoporosis is a condition characterised by low bone mass and micro-architectural deterioration of bone tissues leading to increased bone fragility. It is the leading cause of bone fractures in older adults, and is increasing in prevalence in both women and men, as populations age(2).

Several scientific papers have appeared in recent years supporting Glossy Privet’s beneficial effects in osteoporosis. These include increased circulation levels of vitamin D (1,25-dihydroxyvitamin D3) and improved calcium balance in mature female rats(3,4). Higher bone mineral density and positive effects on bone microstructure, have also been reported following its administration to young male and female growing rats(5-7). As optimising peak bone mass during early life is a key preventive action against osteoporosis, these findings collectively suggest that regular intake of Glossy Privet may well have a preventive effect against this debilitating condition in humans.

In Asian traditional medicine Glossy Privet is also used to treat menopausal problems, blurred vision, tinnitus, rheumatic pains, palpitations, backache and insomnia(8). Other traditional applications supported by recent scientific studies include protection against liver toxins(9, 10), and inhibition of the Hepatitis C (HCV) virus(11).

In China, as with other medicinal herbs, Glossy Privet fruits are sometimes used as an adjunct in cancer therapy (12). Researchers have reported enhanced sensitivity of human colorectal carcinoma cells to the chemotherapy drug doxorubicin(13). Inhibition of the mutagenic activities of benzo(a)pyrene(14) and aflatoxin B1(12) suggest cancer chemopreventive properties, and laboratory studies implicate potential applications in the treatment of human hepatocellular(15) and brain(16) cancer. Animal studies also suggest a possible therapeutic role in diabetes, including protective effects against diabetes-related reproductive deficits(9, 17, 18), and high fat diet-induced obesity(19).

There is clearly potential merit in further evaluating potential therapeutic applications of the fruits of this tree, now found throughout New Zealand and endemic in many other countries. Research to date strongly suggests a significant opportunity for medical herbalists and other clinicians, researchers, health funding providers and conservation agencies, to collaborate to further investigate such medicinal applications. Harvesting its berries and processing these into a prophylactic as well as treatment for osteoporosis alone, would reduce its spread and help protect New Zealand’s precious environment with less use of chemical control measures. This would at the same time also help to reduce Pharmac’s spending on biphosphonates and other osteoporosis treatments, thus potentially enabling more funding towards expensive new generation cancer drugs.


  1. New Zealand Plant Conservation Network, www.nzpcn.org.nz
  2. Cawthon PM et al, Ther Adv Musculoskelet Dis 2016; 8(1):15-27
  3. Zhang YZ et al, J Econ Entomol. 2008;101(4):1146-51.
  4. Dong Xl et al, Menopause. 2010;17(6):1174-81.
  5. Feng X et al, Calcif Tissue Int. 2014; 94(4):433-41.
  6. Lyu Y et al, J Bone Miner Metab 2014; 32(6):616-626.
  7. Rasmussen PL, Phytonews 40, ISSN 1175-0251, Phytomed Medicinal Herbs Ltd, November 2014.
  8. Gao L et al, Nat Prod Res 2015; 29(6):493-510.
  9. Yim TK et al, Phytother Res 2001; 15(7):589-592.
  10. Gao D et al, Phytother Res 2009; 23(9):1257-1262.
  11. Kong L et al, Antiviral Res 2013; 98(1):44-53.
  12. Wong BY et al, Mutat Res 1992; 279(3):209-216.
  13. Zhang JF et al, Integr Cancer Ther 2011; 10(1):85-91.
  14. Niikawa M et al, Mutat Res 1993; 319(1):1-9.
  15. Hu B et al, Oncol Rep 2014; 32(3):1037-1042.
  16. Jeong JC et al, Phytother Res 2011; 25(3):429-434.
  17. Feng SL et al, Asian J Androl 2001; 3(1):71-73
  18. Zhang Y et al, J Ethnopharmacol 2014; 158, PtA:239-245.
  19. Liu Q et al, Nat Prod Commun 2014; 9(10):1399-1401