In today’s Academic Minute, Dr. Michael Bunce of Murdoch University explains his work using DNA testing to identify the non-declared contents of some traditional Chinese medicines.
Mike Bunce is lead researcher at the Ancient DNA Research Laboratory at Murdoch University in Perth, Australia, where his research interests revolve around using ancient DNA to study evolutionary processes and to investigate past biodiversity. He has worked on a variety of projects with the common theme of extracting and amplifying degraded DNA. These projects include studies of New Zealand’s extinct birds and obtaining DNA profiles from ice/sediment cores.
Dr. Michael Bunce – Animal DNA and Traditional Chinese Medicine
The last 5 years has seen some massive changes in how researchers go about sequencing the building blocks of life also know as DNA. To put this in perspective the first human genome took 10 years to piece together - this can now be completed in a day. Researchers are now investigating how this technology can be used in environmental applications.
At our lab we routinely get asked to conduct DNA based species identification of items seized by customs – these are things like ivory , animal furs and traditional Chinese medicines, or TCM. The issue with TCM is that plant and animal products are processed into pills, powders, teas and potions - this processing makes identifications difficult. This is where the new DNA sequencing technologies come into play.
We conducted a detailed genetic audit of 15 TCM samples - the results don’t make pretty reading: the TCMs routinely contained undeclared plants and animals.
To cite an example, a product labeled ‘100 per cent Saiga Antelope Horn Powder” contained DNA of the critically endangered Saiga antelope but also contained significant quantities of sheep and goat DNA. Other TCMs contained; black bear, Asiatic toad, cow, water buffalo and deer.
The plant audit revealed at least 68 families of plants - of concern to consumers is that some of the TCMs contained undeclared Ephedra and Asarum species. These plants are illegal in the US, and can contain chemicals which are toxic if the wrong dosage is taken - none of the TCMs actually listed a dose.
There are polarizing views on the subject of herbal medicines – but irrespective of where you sit on use of these products most would agree that they should be legal, safe and accurately declare their ingredients – the DNA auditing approach is a step towards ensuring consumer safety and the protection of endangered species used in traditional medicines.