The remedy that time forgot

Nick Morrison speaks to a researcher looking to the past for inspiration - and asks what medicines could be hidden inside other herbs.

"SOME of my colleagues won't talk about it, they think I've gone off the rails, but I think it might be quite exciting." Elaine Perry is reluctant to go into too much detail about how her colleagues view her work, but it's clear some of them have been less than enthusiastic. In the past, she's pinned some of the press cuttings to the noticeboard, but they generally pass without comment. "There are a lot of my colleagues who don't want to know what I'm doing," she notes, sadly.

It's fairly safe to assume that this reaction derives from a scepticism -probably quite widespread in the scientific community - towards research which seems to owe as much to folklore as to hard science. But it is by combining the two that Professor Perry and her team have made some quite startling findings.

Last month, the Medicinal Plant Research Centre (MPRC), of which Prof Perry is director, revealed that clinical trials had found that sage could help boost memory power, raising hope that it could be used to treat people suffering with Alzheimer's disease. Oil had been extracted from sage and given to volunteers, who were then given word recall tests at intervals of between one and six hours later. Those who had been given the sage oil performed better in the tests than those who had been given a dummy capsule.

While publication of these findings caused something of a stir in the scientific community, they would have come as no surprise to those familiar with the medicines of the past. Herbalists have long extolled the powers of the herb in improving the memory, with one, John Gerard, writing in 1597 that sage was "singularly good for the head and brain and quickeneth the nerves and memory".

And nor is sage the only herb investigated by the MPRC, a joint venture between Newcastle and Northumbria universities which is more a collection of like-minded researchers than a place. Melissa, or lemon balm, has also been found to make Alzheimer's patients less agitated.

The centre has its roots in work carried out by students ten years ago, when a number of plants which were said to improve memory were tested. Prof Perry admits the project had largely been a way of keeping the students quiet, and was as startled as anyone when the results showed some of the plants had quite significant effects.

"I thought herbs were for cooking, and didn't think much of it at the time, but when we got the results we were all pretty surprised and we made them do the work over and over," she says. "We got reasonably excited and it seemed we were making a link between traditional knowledge and modern science."

The results inspired Prof Perry to scour archives to look at the supposed medicinal properties of other plants - and encouraged others who shared her belief in the potential of traditional remedies to come together in the MPRC.

"The strategy is to get the plants from the traditional archive and take them into the labs and then into the clinics for testing," says Prof Perry. For sage, this has seen chemists analysing the plant and detecting what seems to be the same sort of biological processes as those which protect a chemical messenger, which carries information in the brain. This messenger is broken down in Alzheimer's patients, so protecting it could help reduce memory loss. Unlike conventional drugs, the sage oil appears to have no unpleasant side- effects.

But helping people with Alzheimer's may not be the only benefit. By understanding how sage works, it may be possible to understand more about how the brain works. "If we really have a plant that improves memory, we may learn more about memory itself," says Prof Perry, adding: "The knowledge that has been accumulated about it might lead us not just to benefit health, but also to increase our understanding of the basic mechanisms of the brain."

Using plants as the basis of medicines is not revolutionary. The opium poppy has been used to help babies sleep and in teething for thousands of years, and morphine, derived from opium, is still considered the best pain-killer. Anti-cancer drugs have been derived from the yew tree, and until early last century foxgloves were used to treat heart problems, although they had limited appeal, as too high a dose could kill.

"That is why some people believe plant medicine will never really make it," says Prof Perry. "The downside is how to get an accurate dose and to standardise the plant material. How can you tell that one batch of sage will work and another won't? Even identifying a species is difficult: there are two or three hundred species at least, and lots of varieties within that."

And not all plants said by traditional herbalists to be beneficial have so far been found to have any chemical basis for their powers. The Greeks set great store by rosemary as a memory-booster, but laboratory tests have not found any relevant reaction going on, unlike that in sage. This does not mean it may not work, just that there's no scientific reason to think it might, at least not yet.

The success of the sage trials suggests there may be a huge, largely untapped, resource out there, of plants which could be used as the basis for medicines. The pharmaceutical industry may not want to know - plants cannot be patented - but they may prove to be an alternative to conventional drugs.

But although Prof Perry and her team believe that sage could improve powers of recall, there is no clear explanation of how this works, and this may help explain why some scientists look on her work with caution. Prof Perry admits that her initial approach to set out a clear chemical process was somewhat optimistic.

"One of our great ambitions was to isolate the active chemical, but now I think that was a bit nave," she says. "In most instances, it is clear there isn't a single potent active chemical - it looks as though it is an interaction between different chemicals. That means it's very hard to say exactly how the plant works, by doing this or that to your brain.

"That is why some scientists object: they say 'How are we ever going to understand this, if the plant contains 10,000 chemicals and we can't say which ones are doing what?'. That's an issue, but some people say it is almost pointless looking for the chemical, just look at the whole plant, and that's what we're doing.

"We may not know precisely which chemical in the plant does it, but we know it does have an effect. We know the plant extract has some relevant chemical effect, so it makes sense at some level. We can't tell you exactly how it works, but it does."