Traditional medicine gets a bad press. Labelled as a collection of last-resort cures favoured by quacks that often do more harm than good, it has long occupied the backwaters of what Westerners view as modern medicine.
But in the East, things are different. Traditional Chinese medicine has been used for thousands of years to treat everything from constipation to infertility using, among other things, potent mixtures of plants. And, by and large, it seems to be successful: in China there are thousands of hospitals that specialise in traditional health care and business is booming.
Now, the West's powerful drugs industry wants in on the action.
Enticed by the promise of new treatments that traditional Chinese medicine could offer, a team of scientists from British universities and pharmaceutical companies went on a mission to China to find out the truth behind the promise. That was six months ago. Their results, published today, demonstrate just how much western scientists still have to learn.
The trip took in universities, institutes and drugs companies. Some were based on traditional medicine, others specialised in western medicine and some specialised in both.
The big difference between traditional Chinese medicine and its western counterpart is identifying the active ingredients in the drugs. "In western medicine, all of them are single compounds, so it's much easier to quality-control and you can analyse the mode of function," says Zudong Liu, a medicinal chemist and managing director of Great Chinese Herbal Medicine (UK), who went on the trip. "In Chinese medicine, because you use a mixture it's very difficult to investigate how it works."
One of the ways that pharmaceutical companies are looking at bringing Chinese tradition into western medicine is to identify the active ingredients in the herbs that are used. "There may be some lead compounds to be discovered in Chinese medicine and if these could be identified, they could become traditional western medicines and be subjected to that sort of quality control," says Robert Hider, head of the school of biomedical sciences at King's College, London.
The problem, of course, is that many herbal medicines use several different plants at once - and these could contain thousands of active chemicals. In certain cases, a single active compound has been identified and isolated; the best example is the anti-malarial drug artemisinin. This is rare, however, and chemists worry that purification of the main active component of a mixture may lead to higher toxicity.
Despite the concern, the mission came back from China with a clutch of potential drugs. One could be used to treat Alzheimer's; others are antibacterial agents that could enhance cancer therapy. The scientists also discovered anti-fungal compounds, and equivalents of morphine and nicotine derived from marine organisms.
Western pharmaceuticals are very tightly regulated. They are only approved for prescription once several clinical trials, which measure how well they work and how safe they are, have been carried out, and precisely how they work is clearly understood. In contrast, Chinese medicines, in Britain at least, are regulated as foods, so the requirements for evaluating them are much less stringent.
In China, however, Hider found that traditional medicines were heavily controlled. "The staff who operate in the clinics over there go through quite extensive training," he says. "There are degrees of five years before you can practise in traditional Chinese medicine."
And the majority of doctors who practise traditional medicine are also qualified in the western system. Depending on the complaint, they will use both types of medicine to treat their patients.
Most promisingly, Chinese doctors go to great lengths to underpin their medicine with science. Since 1983, Guang An Men hospital in Beijing has carried out clinical trials of more than 400 traditional medicines. The doctors there even treated some victims of Sars with traditional medicines last year. "We thought that they really didn't do clinical trials over there but increasingly they are and increasingly these are quite well controlled," says Hider.
The idea that Chinese medicine comprises a bunch of plant extracts that have been used for thousands of years and passed on by word of mouth, is off the mark, says Hider. There's more science to it than that.
The evidence from these successful trials is certainly encouraging. But bringing the Chinese tradition of medicine into the west still faces significant scientific hurdles.
First comes quality control. Making sure that the plant extracts being used to formulate a particular medicine are of the right quality is a big headache. "The quality of the extracts varies greatly," says Monique Simmonds, a plant biologist at Kew Gardens in London, who has been working on analysing the herbs used in Chinese medicines. Pharmaceutical companies involved in mass-producing traditional medicines often outsource their procurement of plants and extracts. But if the plants are of the wrong type or low quality and don't have the right profile of chemical compounds needed for the traditional medicine, there could be major problems.
Simmonds says the solution is to go into the field and collect the plants and other materials being used in the treatments so they know exactly what chemicals are in them. They must also know how any processing - being cooked with other ingredients for example - affects those chemicals. "If it is cooked with something like honey or liquorice, then we've got a sample of that same material that's been prepared in that same traditional way. So we can see the subtleties that occur in the chemical fingerprint of that plant."
Maintaining a central record of all the chemical fingerprints of all the plants used in traditional Chinese medicine would keep the standards high.
Another potential hurdle for the adoption of Chinese medicines by the west could be the problems faced by pharmaceutical companies in controlling the supply of raw materials.
With a western drug, the active ingredient can be manufactured as needed in laboratories. Things are not so easy with herbal medicines. "In a mixture formulation [where] you cannot isolate one [active] ingredient, you are totally dependent on the resource, which is not available extensively in Europe or maybe only one isolated area, so you are not in control," says Liu. Without this control, pharmaceutical companies may be reluctant to invest large sums of money in developing new drugs.
But the potential rewards are not to be sniffed at. The global market for Chinese herbal medicines is worth about £8.5bn. Right now, Chinese manufacturers only account for an estimated 3-7% of the market outside their home country but the government there wants to raise its share and sees collaboration with international companies and universities as the way forward.
Even in the UK, the market has been growing steadily over the past few years. Liu has seen demand for his services rise by 20% year on year, he says.
But however well the Chinese regulate their side of the practice, it will be for nothing if other countries fail to adopt standards for traditional medicine.
According to Liu, the British government should draw up clear regulations to control traditional medicines. "People can open anything - nobody will check their qualifications, nobody will check their product standards," he says. "There's an opportunity to make money but there's a very serious risk because you are dealing with medically functional products. Any medically functional product will have some instance of toxicity." Understanding that toxicity means that it can be controlled, but it requires proper training. Increased regulation would also raise confidence in the potential patients of the traditional medicine, says Liu.
Hider agrees that Chinese medicines cannot continue to be marketed as foodstuffs in Britain."They need to be properly controlled and administered through licensed pharmacies," he says. "To do that, there needs to be a lot of work on the quality control of the medicines and proper clinical trials - so it's not just hearsay, there's proven evidence that this particular extract does have a beneficial effect. One needs facts."
