Kew to weed out dangerous Chinese herbs

DO YOU know your Stephania from your Aristolochia? Would you recognise correctly-processed fuzi? Or be able to reject a fake orchid tuber?

Probably not, but ignorance of Chinese herbs, an increasingly popular treatment in the West, can be dangerous. In Belgium, up to 80 women seeking a slimming cure were supposed to have been prescribed Stephania, but instead received Aristolochia, which has the same Chinese name but causes serious kidney damage.

A study by Guy's Hospital in London found 14 cases of liver damage and failure that arose from various traditional Chinese prescriptions for eczema. Two deaths from liver failure in Britain have been blamed on Chinese herbal medicines.

Ensuring good herbs is not easy. Different batches can have different levels of active ingredients, and correct preparation is crucial. Fuzi, for example, is used for rheumatism, but if improperly processed may cause cardiac problems.

In Britain, where anyone can legally set up as a practitioner of herbal medicine, imports of sub-standard or misidentified Chinese herbs are increasingly worrying both plant scientists and qualified practitioners of traditional Chinese medicine (TCM). The Royal Botanic Gardens at Kew is setting up an authentication centre to weed out some of the contaminated, misidentified, and fake TCM herbs on sale.

Christine Leon, a botanist from Kew, has spent the past month collecting plant samples from southern Chinese provinces as a first step in establishing the centre, the only one in the West. On Friday she was at a seminar of experts in Peking, where she said: "Working with our Chinese colleagues, we are trying to help establish a safe supply of Chinese herbs outside China."

In 1996 Britain's 3,000-odd TCM clinics wrote a million herbal prescriptions, commonly for eczema, arthritis, psoriasis and rheumatism. Herb imports from China jumped from 160 tonnes in 1991 to nearly 9,900 tonnes in 1995, but up to a quarter are reported to be of doubtful authenticity.

This is not simply a matter of botanical nicety. It can mean herbs contaminated by pesticide residues, sulphur, or toxic metals. Similar-looking plants are sometimes substituted for rare herbs, despite very different properties. Analysis of some pre-packaged TCM products has found them adulterated with Western pharmaceutical drugs, such as skin ointment containing steroids, and labelling can be inaccurate.

Since 1987 the British Register of Chinese Herbal Medicine has set minimum qualifications, and now has about 350 qualified Chinese physicians as members. Kew will establish a reference collection of 400 to 500 medicinal plants, prepare chemical, anatomical and molecular profiles on TCM herbs and set up a laboratory service to check herbal identity which can be used by importers and practitioners if they want to investigate suspect herbs.

"What we are looking to do is come up with the most reliable and cost- effective tests - replicable tests for each herb, - which we will carefully document and publish. We'll even try to design some kind of a batch testing scheme, to do spot checks on herbs... in bulk," said Ms Leon. Included in the reference data will be samples of poor quality herbs, substitutes, adulterants and fakes. Private funding has been raised for the pounds 250,000 first phase, but more money is needed for the pounds 700,000 total cost.

"In the UK there is no official or unofficial quality control system," said Ms Leon. So standards have been defined by the 16 Chinese herb importing companies and the variable competence of practitioners. "Some of them are extremely well trained. Others, sadly, are not. They simply do not have the resources, the training, the expertise to check on the quality and the identity of the herbs they are handling and dispensing to their patients.... The UK and the Western market as a whole is therefore very prone to exploitation, especially by unscrupulous dealers."