Australian border officials seized 15 TCMs (traditional Chinese medicines), which researchers from the Murdoch University analyzed to reveal the animal and plant composition by using new DNA sequencing technology. The results, published in PLoS Genetics, showed that some of the analyzed TCM samples contained potentially toxic plant ingredients, allergens, as well as traces of endangered animals.
Leading researcher, Dr. Bunce, and a Murdoch University Australian Research Council Future Fellow commented:
“TCMs have a long cultural history, but today consumers need to be aware of the legal and health safety issues before adopting them as a treatment option.”
The 15 TCM samples were seized in powder form, tablets, capsules, flakes, and herbal teas, and were audited using the DNA preserved in the samples.
Dr. Bunce stated:
“In total we found 68 different plant families in the medicines – they are complex mixtures of species. Some of the TCMs contained plants of the genus Ephedra and Asarum. These plants contain chemicals that can be toxic if the wrong dosage is taken, but none of them actually listed concentrations on the packaging.
We also found traces from trade restricted animals that are classified as vulnerable, endangered, or critically endangered, including the Asiatic black bear and Saiga antelope.”
Until recently, TCM pills and powders posed a major challenge in terms of identifying the substance’s biological origins, yet according to PhD student Megan Coghlan, the research demonstrates that second-generation, high throughput sequencing is an efficient and cost-effective way to identify the species composition.
Coghlan, who is studying the application of DNA techniques in wildlife forensic applications, says:
“The approach has the ability to unravel complex mixtures of plant and animal products.”
Whilst more TCM tests would shed a light on the true extent of the problem, it would also make it easier for customs officials to identify the trade of endangered species, which, due to the rising popularity of TCMs is a business that is worth more than hundreds of millions of dollars per year, with figures rising.
“We found multiple samples that contained DNA from animals listed as trade-restricted according to the Convention on International Trade in Endangered Species Legislation. Put simply, these TCMs are not legal.”
Another worrying aspect of TCMs is product mislabeling. Consumers are not aware that the product contains ingredients, such as animal DNA and potential allergens like soy or nuts.
Dr. Bunce explains:
“A product labeled as 100 per cent Saiga antelope contained considerable quantities of goat and sheep DNA. Another product, Mongnan Tianbao pills, contained deer and cow DNA, the latter of which may violate some religious or cultural strictures.”
The consequence of incorrect labeling is that it is difficult to enforce legislation and to prosecute cases of illegal trade.
Dr. Bunce remarks:
“It is hoped that this new approach to genetically audit medicinal products will bring about a new level of regulation to the area of complementary and alternative medicine. Auditing TCMs would assist in prosecuting individuals who seek to profit from the illegal trade in animal products.”
The TCM samples analyzed in this research were seized by the Australian Customs and Border Protection Service, and the International Wildlife Trade Section (Department of Sustainability, Environment, Water, Population and Communities).
Dr. Bunce and his colleagues will broaden the use of the new DNA tests to analyze other herbal medicines in the future.
Written By Petra Rattue