Breaking Down Traditional Chinese Medicine For more than 3,000 years, traditional Chinese medicine has been an integral part of Chinese culture and the predominant medical treatment for a large part of the population. In recent decades, the practice has gained popularity in countries around the world, creating a multimillion-dollar global industry. Traditional Chinese medicine often contains a number of animal and plant components that are meant to act synergistically to treat a particular ailment. Only a small number of products have been scientifically validated, with their perceived efficacy instead promoted through folklore and word of mouth. Researchers have a found number of traditional Chinese medicines to be adulterated with drugs of known pharmacological activity, presumably to increase their effectiveness. Despite the popularity if a given traditional Chinese medicine, the actual contents - frequently in the form of a pill, powder or tea - are often hard to ascertain. Undeclared or mislabeled ingredients can pose serious health risks, however, and traces of allergens, toxic plants and heavy metals sometimes find their way into the treatments. In the 1990s, for example, the toxic herb Aristolochia fangchi was confused for the anti-inflammatory plant Stephania tetrandra at a slimming clinic in Belgium, leading to more than 100 women suffering kidney failure, many of whom later developed cancer of the urinary system. Herbal medicines labeled as food supplements often slip under the radar of regulatory agents like the Food and Drug Administration in the United States or the Therapeutic Goods Administration in Australia, even if their ingredients are not explicitly detailed. Despite numerous cases of adverse reactions, concerns about their efficacy, legality and safety have gone unanswered since no solid method existed to determine their ingredients. Now, researchers from Murdoch University in Australia have answered that call by applying a method called high-throughput sequencing of DNA, capable of producing thousands of genetic readings at once. Past experiments usually analyzed a sample for one target component, like ginseng or rhino horn, but the new method approaches the medicine holistically to see what plants, animals, insects or fish might be present. Though typically used for analyses on the genome level, the researchers honed the technology to sift through a conglomeration of tiny genetic bits that make up any given medicine to audit the species composition. "This is the ideal technique to use to see if herbal products are honestly labeled," said Michael Bunce, a molecular biologist at Murdoch University and senior author of the paper published in PLoS Genetics. Dr. Bunce and his colleagues analyzed 15 traditional Chinese medicines confiscated by customs officials at the Australian border, including powders, tablets, capsules, bile flakes and herbal teas. They were able to salvage non-degraded DNA from 54 percent of the samples, generating more than 49,000 sequence reads. Figuring out which vertebrates were present was relatively straightforward. They found goat, sheep, deer, buffalo, cow and toad DNA, in addition to endangered Saiga antelope and vulnerable Asiatic black bear. Both of the latter species are protected under the Convention on International Trade in Endangered Species, which includes China among its 175 signatories. Eventually, the technique could help customs agents identify illegal wildlife products at borders. "Next-generation sequencing technology is progressing ever month," said Sergios-Orestis Kolokotronis, an evolutionary biologist at Barnard College who was not involved in the research. I would like to believe that this technology - and the portable, low-cost versions we have been hearing about - will be used on all international sides of the illegal trade in biodiversity. Plants were trickier to pin down. For the researchers to identify what species their sample reads correspond with, they must have something for comparison in a database. Many plant species have yet to be sequenced, though bar code of life initiatives are improving the situation. "Significantly more money has been invested in animal DNA bar-coding," said Damon P. Little, the assistant curator of bioinformatics at the New York Botanical Garden, who also was not involved in the study. Plant DNA bar-coding efforts will need a similar investment before the reference database will be of comparable depth. Still, the researchers were able to identify 68 families of plants from the samples. The most common included mint - often used to treat gastrointestinal upset and gallbladder problems - and liquorice root - classified as one of the Chinese 50 fundamental herbs and threatened with species extirpation in some Chinese provinces because of over-harvesting. Among the benign plants, however, the researchers found Ephedra, a poisonous herb banned in the United States, and, within a product labeled as laryngitis medicine, aristolochic acid from aristolochia, a known nephrotoxin, hepatotoxin and carcinogen. "Aristolochic acid is seriously toxic, it has killed people who have taken the wrong dose," Dr. Bunce said. I'd rather have laryngitis than take that material. Over all, 78 percent of the samples contained animal DNA that was not labeled in Chinese or English on the packaging. Saiga antelope horn powder, for example, claimed to be 100 percent pure, yet was laced with traces of goat and sheep. In addition to the mislabeling, a big problem with the medicines was their lack of dosage instruction. Typically, the packaging did not include labels describing how much of a particular ingredient is included in each serving, what dosage people should take or how often they should consume it. People need to be aware of the safety and legality issues surrounding traditional Chinese medicines before adopting them as a treatment option, the researchers wrote. In addition to raising consumer awareness, they hope their method can help authorities like the F.D.A. and the similar agency in Australia develop regulations for traditional Chinese medicine. "Agencies up until now have been looking for auditing tools, but the tools haven't been there," Dr. Bunce said. Hopefully this is a steppingstone toward that.