Genetic audit reveals that some traditional remedies contain endangered animals and toxic plants.
12 April 2012
Chinese herbal medicines contain ingredients derived from endangered animals, toxic plants and livestock, a genetic audit has discovered. Few of these ingredients were listed on the packaging.
“There’s absolutely no honesty in the labelling of these products. What they declare is completely at odds with what’s in there,” says Mike Bunce, a geneticist at Murdoch University near Perth, Australia, who led the study. The results are published today in PLoS Genetics1.
Traditional Chinese medicines rack up billions of dollars in worldwide sales each year, and exports to Western countries are on the rise. However, most of the medicines have not been proved to be effective, and industry regulation is scant.
When the medicines have been ground up, it is very difficult to tell what they are made of. In the past, researchers have examined herbal medicines by running assays for toxic compounds and using DNA tests to determine whether a specific plant or animal is present.
But mislabelling is rampant, so researchers do not always know what to look for and conventional approaches will miss many of the species that are present, says Bunce.
His team turned instead to next-generation DNA sequencers, which can rapidly read thousands of DNA strands. The researchers can then check the genetic sequences against databases to learn which plants or animals they come from. This ‘deep sequencing’ technique has been used to characterize mixtures of microbes living in environments such as oceans and animal guts.