Firstly, I want to acknowledge and say a big thank you to Professor Kerry Bone, for the information in this blog. Kerry and collaborators have done a lot of great research on the various species of Echinacea and if its anyone that knows this herb well enough, it's Kerry himself!
There are so many myths on Echinacea, just today a patient came in an heard something on the morning news about the effectiveness of Echinacea on colds and flu saying that the research showed it wasn't effective. Can I say that there has been a few papers, including a systematic review (Schapowel et al, 2015; PMID: 25784510) showing clinical evidence that some species of Echinacea work to shorten the duration of respiratory tract infections and also IT IS safe to use long term to modulate the immune system.
However using the right part and the right species of the plant does help! From its traditional use by the Native American tribes, it's Echinacea angustifolia that provides the active constituents called alkylamides which exhibit immune modulating properties. It is also the only active constituent in Echinacea that was present in blood after a liquid Echinacea product containing the species E. purpurea and E. angustifolia was taken orally (Matthias et al, 2005; PMID: 15919096). Echinacea purpurea was then discovered in Europe by a German herbalist and the aerial parts of the plant was used, with a different extraction method, however this species is not high in alkylamides as the species E. angustifolia, BUT interestingly enough, it does improve the bioavailability of the alkylamides in the E. angustifolia species, which in turn means that the body can absorb the wonderful properties and phytochemicals in Echinacea. There is actually a patent pending on this finding based on research published in August 2005 by Mediherb and collaborators as Matthias A et al in Life Sciences 2005;77:2018-2029.
So what effect do these alkylamides have on the immune system?
The key findings of in vitro studies are that:
Echinacea does not stimulate the immune system unless there is an immune challenge.
The Echinacea alkylamides tended to modulate the immune response of macrophages and T cells, toning the response down in the face of a strong stimulus, hence helping the immune system to operate more efficiently (Stevenson LM et al Molecules 2005).
The alkylamides are largely responsible for the systemic immune effects of Echinacea lipophilic extracts.
This immune modulating activity is (at least in part) due to the interaction of alkylamides with cannobinoid receptors, specifically CB2 (Gertsch, Schoop & Kuenzle et al, 2004; PMID: 15556647).
Echinacea Premium increased heat shock proteins (hsp70) and increased white cell count. Echinacea purpeura root boosts the number and function of natural killer (NK) cells (a class of white blood cell) (Miller SC eCAM 2005; 2(3):309-314).
That's pretty impressive stuff and I know because I have completed an honours degree in biochemistry so this information is right up my alley! For those who think this is mumbo jumbo, Echinacea is a fantastic herb for possibly not just modulating the immune system but also in assisting the body with inflammation related to immune dysfunction such as in autoimmune disease and also in mood/pain regulation, having interaction with the cannibinoid receptors, thereby improving general wellbeing! The ability of Echinacea to influence heat shock proteins is big news as these proteins have been discovered to play a role in many disease states as they are proteins being made by cells in response to exposure to stressful conditions.
Not all species of Echinacea are equal. Some over the counter products have been shown to contain a different species of Echinacea called Echinacea pallida, which doesn't have the same effect on the immune system, and there is insufficient research to demonstrate it's effects, however, it is used in over the counter products as an adulterated species of Echinacea and so you really do not know what you are getting when you buy complementary medicines off the shelf or over the internet. Some practitioner only products are worth buying, they guarantee the quantity of alkylamides in their product..beware of imitations! This is why high grade Echinacea produces a tingling and numbing effect in the mouth when you swallow it!
However it's not only the correct species that has to be used, it also depends on the extraction method, and other factors such as the quantity of herbs to extract used and under what pressure and temperature, etc. These are all important factors that determine how much of the active constituent or phytochemicals present in the plant is obtained to have some therapeutic value. And as mentioned above, even mixing various type of species of herbs together can give it different properties such as enhancing bioavailability of active constituents.
So there is more to herbal medicine than just picking a plant and seeping it in boiling water to have the right therapeutic effect. It can be a highly scientific process, usually based on traditional methods of how the herb was once used to make sure that the herb is having the right effect in vitro, i.e., once the herb is consumed. However this traditional methodology and knowledge can be lost through the years or either exploited or ignored, ironically by modern research...thinking that we can do better. It's however very exciting when modern research can support the traditional claims of that herb.