Centipeda cunninghamii
A review of Centipeda cunninghamii in the treatment of psoriasis.
C. cunninghamii (A. Br. & Aschers.) is a perennial herb, part of the daisy family, native to Australia. It is known by the common names of “Old Man Weed,” “Common Sneezeweed,” “Scent Weed,” and “Gukwonderuk.” According to the promoters of products which include the plant’s extracts as ingredients, it’s been used for centuries by Aboriginies for numerous health complaints, including external applications for wounds or skin diseases.
Unlike many other plants which have been used traditionally as medicine, there have been no articles about C. cunninghamii in the peer-reviewed medical literature available on Medline. Not one in the last 37 years.
Note well, though, that this plant should not be confused with Centipeda minima, commonly known as “Spreading Sneezeweed.” They are different species, and so any medicinal properties of one cannot be assumed to exist in the other.
There are at least four products based on C. cunninghamii with advertising which mentions psoriasis:
Australian All Natural Back to Nature Skin Balm
Australian O Ointment
Dr. Berman’s™ Aboriginal Gold™
Plantolin® or H Bio-Juven
Australian O Ointment
Dr. Berman’s™ Aboriginal Gold™
Plantolin® or H Bio-Juven
Of the four, only the Plantolin® advertising offers anything coming close to supporting evidence of the claims that the plant can treat psoriasis. The makers of the other three basically just say, “Australian Aboriginies have used it for centuries — it’s good for psoriasis,” and leave it at that. But since the last offers more, the remainder of this article will focus on just the claims made by the Plantolin® web site.
Plantolin® is an extract from C. cunninghamii. Plantolin Australia P/L and H Bio Juven Pty Ltd are a couple of Australian companies which formed a partnership in order to bring products based on Plantolin® to the market. They teamed up with Bio Botanica Inc (USA), which does “analysis and clinical trials.”
The Plantolin® substance is patented in Australia, and also here in the United States (but as Phytoplenolin®, and the complete text of the patent can be found here). The extraction method from the plant is also patented.
But patents are not a good measure of how well a substance treats psoriasis. Good, solid clinical trials are. On the What is Plantolin®?
page, the company claims,Independent clinical double blind studies commissioned by H Bio-Juven and Plantolin® Australia have revealed that Plantolin®… works fast to reduce the inflammation and scaling which are features of Psoriasis…
They have? The site only offers An application of H Bio-Juven Plantolin Skin Balm in eczema and psoriasis treatment
, but it’s not a double-blind study. In fact, it wasn’t blinded at all, and suffers from multiple methodological problems:No control group — there was no “placebo” group with which the results could be compared. Thus, there is no way to know if the level of “success” observed was significantly greater than if the patients had used, for example, a moisturizer without Plantolin®.
Lack of Control of Variables — the manufacturer suggested that the study participants also change their diets and lifestyles, which makes it impossible to say whether or not the product had any effect. The report on the study goes out of its way, several times, to say that few patients made any of the suggested changes, but the author never supplies any number or percentage.
Self-Reported Progress — the trial relied on the participants’ own estimation of how bad (or good) their psoriasis was, and not on a more-objective measure like PASI scores.
Lack of Control of Variables — the manufacturer suggested that the study participants also change their diets and lifestyles, which makes it impossible to say whether or not the product had any effect. The report on the study goes out of its way, several times, to say that few patients made any of the suggested changes, but the author never supplies any number or percentage.
Self-Reported Progress — the trial relied on the participants’ own estimation of how bad (or good) their psoriasis was, and not on a more-objective measure like PASI scores.
Due to these problems, the results of the study are questionable, and far from “conclusive” (which is how they are characterized in the report). At best, what they’ve got is a preliminary test — perhaps the equivalent of the FDA’s “Phase I” (out of 3) trial. A lot more testing needs to be done before anything “conclusive” can be stated.
Overstated conclusions from tests aren’t the only things wrong with the Plantolin® web site. On the page “Treatment of Eczema and Psoriasis without Side Effects
,” they say,Plantolin® is a patented herbal extract derived from the native Australian plant Centipeda cunninghami. Being a product of nature rather than a laboratory means that Plantolin® can be used in products which are completely safe, non-allergenic and free from side effects.
To follow that apparent “logic,” we must conclude that poison ivy, cobra venom, and rabid wolves are all “completely safe, non-allergenic and free from side effects.” They are, after all, “products of nature,” and not created in laboratories. I must say, however, that evidence of any side-effects of the use of C. cunninghanii is lacking, but so is evidence of efficacy. Safety and usefulness are both required before a drug passes clinical trials. Should the same not be true for “natural” substances?
It should also be noted that the above paragraph is found after a couple of other paragraphs full of fear-mongering about the side effects and costs of modern pharmaceuticals. This kind of “it’s natural, so it must be safe” advertising is pretty pathetic, and no consumer with an iota of common sense should fall prey to it. Volcanoes are natural. They aren’t safe.
And speaking of sense — or, rather, a lack of sense — on the same page, they say,
The origin of eczema and psoriasis is unknown. Presumably disturbances in our body chemistry (metabolism) are responsible for these diseases and the skin is only a mirror, which can reflect deeper internal health problems.
That’s quite a presumption. One which ignores most of the current research into psoriasis, which points the finger of blame at the immune system, and not at anything so vague as “metabolism” or “body chemistry.” Also on that page,
The scientists who conducted clinical trials on Plantolin®, while commenting on high success rates amongst test subjects using the product, observed that some sufferers in the test group could expect a long-term recovery from their condition. This is a very promising result, given that eczema and psoriasis are thought to be incurable.
Yes, that’s a clear implication that they think that what they’ve got is a “cure” for psoriasis. Nevermind that the one “clinical trial” they’ve run lasted for a paltry four weeks. Nevermind that it’s only been three years since it happened. Nevermind that there’s not a single word about long-term follow up to be found. One has to wonder if any of the “scientists” (only one of whom, a pharmacist, is named) was a dermatologist, or had any expertise regarding psoriasis at all.
To sum it up, the Plantolin® web site is long on promises and “conclusions,” and short on good evidence and medical knowledge.
Update, May 11, 2010: The Plantolin Web site has been redesigned to be nothing more than the product name and email addresses for Dr. Sandy Schwartz and Graeme Close.