Centipeda cunninghamii: the wonder weed

Centipeda cunninghamii is one of the essential actives in our centess+complex range and an emerging superstar ingredient in anti-ageing skin care formulation. Although we’re only just hearing about and experiencing its benefits for our skin, indigenous Australians have been using its therapeutic superpowers for centuries. But what is it? Where does it come from? And how did we work out that it does wonders for our skin? With this multi-benefit natural extract popping up on more and more ingredient lists, we hope to take you on a whistle stop tour of all there is to know about Centipeda cunninghamii in the most comprehensive one-stop-overview you’ll find on this bioactive botanical.

Introducing Centipeda cunninghamii

Centipeda cunninghamii is commonly known as Old Man Weed coming from the literal translation of its indigenous name Gukwonderuk. It was also given other common names like ‘scent weed’ (it smells like mint and pine) or ‘sneezeweed’ (its dried, powdered flowers were once used as snuff) though these names were assigned by European settlers these are gradually falling out of use. The plant is indigenous to Australia and New Zealand, but its habitat has expanded over time to include Asia and with some introduction to Canada and Europe. Until the end of last century, Centipeda cunninghamii (C. cunninghamii for ‘short’) was studied as part of a collective group of related plants termed Centipeda minima, and as such detailed and accurate scientific data about this particular plant was scarce until interest in its bioactivity was sparked again a few decades ago. The indigenous habitat of C. cunninghamii can be found along the banks of the Murray River, Australia’s longest river (2,500km) which also serves as the territorial border between New South Wales and Victoria. The plant has long been used by the indigenous Koori tribe for its medicinal properties to treat a wide range of ailments. Even though the biological effect of plants used in traditional medicine are rarely understood or questioned, many therapeutic natural extracts have been administered safely for hundreds of years. Similarly to many other botanicals used traditionally to treat various medical ailments, the biology and chemistry behind the bioactivity of C. cunninghamii is yet to be exhaustively understood, however a clear resurgence of interest in chemical and biological investigations of traditional medicinal plants provides us with better insight all the time. This is highlighted by the increased number of research publications in this field in the last 15 years, particularly from China and India where traditional Ayurvedic and Chinese medicinal practices are historically and socially prevalent. Understanding the science behind the medicinal properties of these naturally beneficial extracts allows their therapeutic use to be expanded and to maximise the efficacy of natural products.

Traditional uses of Centipeda Cunninghamii 

The Koori tribe originally populated the South East Australian territories of New South Wales and Victoria, with most of the population centred along the Murray River at the time of initial European settlement, and much like the current population distribution with most Australians living in the South East. C. cunninghamii or Gukwonderuk was just one of the plants used by the tribe for its medicinal properties, and teas or other preparations were popularly used to treat various ailments such as coughs, colds and skin irritations, and even tuberculosis.¹ The stems and leaves were boiled in water to make a tea for oral ingestion, or to prepare a solution for topical application to externally inflamed skin or abrasions and cuts.² Another method of medicinal administration involved tying the plant to the body and using body heat to naturally draw the plant secretions out onto the skin. Other uses cited include treating opthalmia (or inflammation of the eye) in conditions like conjunctivitis.³ The plant’s scientific name was inspired by Allan Cunningham (1791-1839) who was an English botanist and explorer, renowned for his travels to Australia and New Zealand to collect plants. Scientists have long been interested in discovering and cataloguing new plant species, and now in the digital information age the scientific disciplines of ethnobotany and ethnomedicine (see Definitions below) play a vital role in preserving the traditional medicinal practices, and associated historical, cultural and societal knowledge and usage of natural products with fears that oral tradition may not preserve the rich knowledge amassed by Aboriginal tribes who have lived in and off the coast of Australia for 40,000 years. Definitions Ethnobotany: the scientific study of the relationships that exist between people and plants. Ethnobotanists aim to document complex relationships between cultures and uses of plants in that society. Includes plant uses as foods, in medicines, clothing, ritual, dyes, cosmetics and more. Ethnomedicine: the study or comparison of traditional medicines practised by various ethnic groups, especially by indigenous peoples.

General health benefits and uses

Holding up the traditional belief of being able to treat ‘just about anything’, extracts of the plant are being used in the development of a wide range of skin care products. Effective in the treatment of a diverse array of ailments, the therapeutic effects of C. cunninghamii can be attributed to its anti-inflammatory, anti-microbial and anti-oxidant properties. The extract of Old Man Weed can be used as an: Anti-inflammatory for calming inflammatory skin conditions like acne, rosacea, psoriasis, or to soothe cuts and abrasions Anti-microbial (antiseptic) reducing risk of infection in healing cuts, abrasions and skin conditions Anti-oxidant in anti-ageing formulations and in promotion of cell renewal processes Anti-protozoal⁴ in treating parasitic infections and a Sunscreen preventing skin damage caused by UV Research shows that C. cunninghamii has anti-inflammatory activity comparable to Ibuprofen and Celebrex, with the most recently identified novel bioactive compounds showing greater anti-inflammatory potency than aspirin.⁵ What’s even more interesting about this is that C. cunninghamii shows the potential to inhibit inflammation through both types of inflammation pathway- most Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) inhibit one pathway or the other, not both. This significant anti-inflammatory potency means C. cunninghamii is of great interest in administering pain management and is being investigated by researchers in treatment of inflammatory conditions such as rheumatoid arthritis, osteoarthritis and other inflammatory conditions such as multiple sclerosis.⁶ Studies also showed that half of the components of C. cunninghamii show anti-oxidant activity at levels comparable to the major antioxidant constituent of green tea, epicatechin. Reactive oxygen species (ROS) are constantly generated in the body as an integral product of metabolism, by exposure to environmental factors and as a consequence of inflammatory processes. These ROS can damage cellular structures and DNA in the body through oxidative processes. Over 100 diseases give rise to a pathological increase of free radicals. Utilising the natural anti-oxidant properties of C. cunninghamii could be explored in the treatment of cancer, diabetes, cataracts, cardiovascular disease, male infertility, renal disease, liver, lung, neurological and inflammatory diseases. Various extraction methods and different preparations of C. cunninghamii have been patented for a diverse array of therapeutic uses, including rhinitis, cancer, bone fractures, herpes, pruritis and topical treatments for skin ageing. It has also been patented for hair growth, skin disorders, gingivitis and as an anti-protozoal.

Botany and grow it yourself

A perennial herb of the daisy family, Asteraceae, C. cunninghamii is identifiable by its unique leaf shape and a highly aromatic scent reminiscent of pine and peppermint.⁷ It has tiny globular flower heads, usually green in colour, that flower in the warmer months of September to February in Australia. Grow your own⁸ In nature, C. cunninghamii can be found generally anywhere there is water, especially in low lying or swampy areas. Keep this in mind if cultivating the plant yourself- C. cunninghamii needs moist soils but can tolerate being inundated with water. A great plant for situating along pond edges or as ground cover for bog gardens. The plant does best when positioned in a sunny location. You can successfully propagate C. cunninghamii from seeds or cuttings, and regular pruning should encourage dense growth. If you plan to grow your own and self-administer, it’s worth introducing low levels of the extract at first into your diet or on your skin. In the case of oral ingestion, some traditional medicine authorities have recommended regulating the dosage as the plant may be toxic in large amounts. There’s no evidence to suggest associated toxicity with moderate usage however it’s worth taking the time to assess your tolerance of any new supplement and stop using the extract should any side effects occur. If in doubt, please contact a herbalist or complementary therapist. The Therapeutic Goods Administration (TGA) don’t specify any concentration/usage restrictions for Centipeda cunninghamii, though there may be export restrictions from Australia as it’s a native plant.⁹

Bioactivity and associated components of the plant

Despite a long history of traditional use as a medicinal plant for treating wounds, infections and inflammation, it’s only relatively recently it captured the attention of researchers at Southern Cross University, New South Wales. In collaboration with the government and industry, significant advances were made in identifying the plant’s chemical composition and biological activity, supporting earlier research that had already identified the anti-microbial and anti-fungal activities of C. cunninghamii. Establishing the scientific rationale for the therapeutic actions of C. cunninghamii and other traditional plant medicines serves as a starting point for the development of more effective drugs. Understanding the origins of its bioactivity will also allow appropriate administration of the plant extract, including topically in increasing the use of effective natural skin care products and treatments instead of petrochemical-based formulations. Read on to learn about some of the compounds that have been identified as responsible for the different medicinal properties of C. cunninghamii.

Anti-inflammatory and anti-oxidant compounds

Five flavonoids were isolated from the flowers of C. cunninghamii, and are thought to be responsible for the extraordinary suite of medicinal properties of the plant. Flavonoids are the most common group in a wider class of compounds called polyphenols (meaning multiple phenol rings) which are widely known to be highly bioactive. Flavonoid is the general name we give to any substance of a large class of plant pigments that has a structure similar to the compound flavone (pictured right). Together with carotenes (the molecules that give carrots their colour), flavonoids are also responsible for the pigmentation of fruits, vegetables and herbs. The structure of these molecules- that is containing many connected benzene rings- is the basis of both the colourful and anti-oxidant nature of these compounds as they allow electrons to move relatively easily around the structure. Numerous medicinal plants contain therapeutic amounts of flavonoids and are used as anti-inflammatory, anti-viral, anti-cancer and anti-allergic agents. Some flavonoids also possess anti-microbial activity– and inhibit a variety of human pathogens including bacteria, fungus and viruses.¹⁰ The many biological effects of flavonoids are linked to their ability to act as strong antioxidants and free radical scavengers, with the ability to bind to enzymes, receptors and metals in the body. Red wine, tea, fruits and soy contain high levels of dietary flavonoids, however, due to poor bioavailability the direct anti-oxidant value of dietary flavonoids has been called into question. However, a diet too rich in some flavonoids can lead to some adverse estrogen-mimicking effects that places these substances in the class of endocrine (or hormone) disrupting chemicals. The flavonoids can be very structurally similar to the human hormone, estradiol, and as such the body isn’t able to distinguish between them. This means that some plant-derived flavonoids mimic the hormonal effects of estrogen in the body, which isn’t always a good thing. The estrogen-mimetic (or phytoestrogenic) effects of dietary compounds are being researched to prevent the symptoms and effect associated with estrogen imbalance, such as estrogen deficiency in women during menopause, or the development of estrogen-dependent cancer. Upon development of certain hormone-related medical conditions it’s a good idea to consider making some dietary and skincare changes to redress the estrogen balance in a way that is appropriate for that medical condition. It’s always best to speak with your healthcare practitioner who can recommend the best foods, personal care and skin care solutions for you should you develop an endocrine-disrupting condition.  Terpenoids make up no less than 60% of all known natural products. The largest group of natural products, plant terpenoids are used widely for their aromatic qualities in flavour and fragrances and also play a role in traditional therapeutic herbal remedies. Anti-inflammatory, anti-oxidant, anti-microbial as well as insecticidal, terpenoids are synthesised in plants as ‘chemical warfare’ to protect itself from bacteria, herbivores and other external threats. Plants evolve these compounds as a form of self-defence but in the process give us some of nature’s finest remedies. Some terpenoids you may have heard of are menthol, camphor and quinine, with the characteristically strong scent and flavour profile associated with terpene-derived compounds. Terpene-derived compounds give turmeric, tomatoes and sunflowers their vibrant colours and contribute to the flavours of citrus fruit, ginger and cinnamon. A series of caffeic acids were also isolated as the major components of the plant stems. The caffeic acids are a polyphenol subgroup of acid compounds with many biological effects including significant anti-oxidant and anti-inflammatory properties and it is suggested they may also support immune system function.¹¹ Caffeic acid is a substance found in many plants and foods, though coffee is the main source of caffeic acid in the diet. Wine also contains significant amounts of caffeic acids, as well as apples, berries and artichokes.

Thymol: a spotlight on the main bioactive component Terpenoid thymol is the main bioactive constituent of C. cunninghamii, and can be found in lower concentrations in the herb thyme. With significant anti-microbial activity it is part of a class of compounds known as biocides (ability to kill bacteria and harmful organisms) and as such has strong antibiotic and antiseptic properties. Studies have also shown that natural biocides like thymol can reduce bacterial resistance to commonly prescribed anti-microbials such as penicillin.¹² Thymol also possesses powerful antioxidant properties, is anti-inflammatory and anti-fungal and is likely to contribute much of this bioactivity to the impressive therapeutic profile of C. cunninghamii.

For further reading, check out some of the Centipeda cunninghamii studies and information referenced throughout the article or why not find out more about some of the other naturally effective griffin+row ingredients in our active ingredient series?

Read about the five simple steps of the griffin+row skincare system: 1 Cleanse     2 Exfoliate     3 Hydrate     4 Nourish     5 Enrich

 

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References and sources

1. Campbell, A. Pharmacy of Victorian Aborigines, Aust. J. Pharm., 54, 894-900, Dec-Jan 1973-1974.
2. Smyth, R. B. Aborigines of Victoria, Vol. 2, p. 173. Trubner: London 1878.
3. Maiden, J. H. Useful Native Plants of Australia, p. 195. Trubner: London 1889.
4. D’Amelio, F. S., Mirhom, Y. W. Therapeutic Composition for Treating Skin Using Centipeda Cunninghamii Extract, World Patent WO9838971, Sept 11, 1998.
5. Beattie, K. D. Phytochemical studies and bioactivity of Centipeda and Eremophila species, PhD thesis, Southern Cross University, 2009.
6. Leach, D. et al Biologically Active Compounds, US Patent US8299119B2, Oct 30, 2012.
7. https://www.nzpcn.org.nz/flora_details.aspx?ID=2085 New Zealand Plant Conservation Network Flora database.
8. https://anpsa.org.au/foodplantsSG/AFPSG26.pdf Australian Food Plants Study Group Newsletter, Association of Societies for Growing Australian Plants, Number 26, February 1996.
9. https://www.tga.gov.au/sites/default/files/cm-listed-substances_0.pdf Substances that may be used in listed medicines in Australia, Therapeutic Goods Administration (TGA). Last updated 2015.
10. Bylka W. et al Natural flavonoids as antimicrobial agents, Journal of the American Neutraceutical Association, 7, 2, 24-31, 2004.
11. https://www.webmd.com/vitamins-supplements/ingredientmono-1266-caffeic%20acid.aspx?activeingredientid=1266&activeingredientname=caffeic%20acid WebMD Vitamin and Supplement Database
12. Palaniappan, K., Holley, R. A. Use of natural antimicrobials to increase antibiotic susceptibility of drug resistant bacteria International Journal of Food Microbiology 140 (2–3): 164–8, 2010.

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