Science takes a closer look at the power of plants

[Guest guest]

.....and I thought _I_ was always the last one to know things....hey!

I'm ahead of Science! :-)

 

deb

 

http://www.guardian.co.uk/Print/0,3858,462103,00.html

 

Researchers at Kew Gardens want to know how figwort heals wounds, why

basil might treat Parkinson's disease, which sage might provide an

answer to dementia - and why an onion a day might keep the doctor away.

 

The work involves a look at what is sometimes called herbal healing or

old wives' tales, but which has delivered a range of powerful therapies

over the centuries, from digitalin from foxgloves to aspirin, from

willow and meadowsweet.

 

" We go back in the literature, find that it has been used, scratch our

heads and say, 'What is known about these plants cannot explain their

medicinal property: should we go back?' We are doing that more and

more, " says Monique Simmonds, of the Royal Botanic Gardens at Kew.

 

" When you get a similar thing coming up again and again in different

cultures, you should keep an open mind for scientific evaluation. "

 

Prof Simmonds is one of the advisers behind Field Hospital, a pavilion

which opens at Kew this month, exploring the use of sphagnum moss to

treat wounds in the trenches of the first world war (it later turned out

to contain the penicillium microbe), the healing properties of feverfew,

eyebright and yarrow, and why dock leaves are good for nettlerash.

 

Researchers have already confirmed that medicinal leeches could reduce

post-operative swelling. Leech saliva also contains an anticoagulant

called hirudin now used in cardiovascular surgery.

 

Such lessons from the past have sent researchers back to forests,

marshes, meadows and deserts in search of new drugs from old healing

herbs. The Pacific yew provided taxol, the cancer drug, more than a

decade ago.

 

Prof Simmonds and colleagues at Leicester University have begun to

explore the use of terpenoids, a class of essential oils from plants, in

wound healing. They are also analysing salvia or sage, proposed as a

treatment for Alzheimer's, and figwort for treating diabetic ulcers.

 

But even plants of the same species produce chemicals of differing

potency at different times of the year in different environments.

 

Families such as the salvias and ocimums - basil and other aromatic

herbs - are huge. Whatever does the trick in China may not help in

Chesterfield.

 

The research raises questions of intellectual property and sovereign

rights.

 

So Kew is working with other nations, and within the United Nations

convention on biological diversity, to re-examine research by

generations of chemists and collectors.

 

" The literature is so full of bad science on medicinal plants, " says

Prof Sim monds.

 

" There are no vouchers of the plants that were used, so you cannot check

if they used the right species. Often they used local names, and local

names change. "

 

Such research has also begun to lead her in unexpected directions: to

rice and rice bran as a staple with properties that might explain why

cancer levels are lower in some regions.

 

" It is highly likely that diet has a huge effect on susceptibility to

cancer. But have we lost some of the protective elements by breeding

them out? We have bred things out that could have beneficial effects, "

she says. Such questions could be answered by the new science of

ethnobotany: the partnership of science and local or tribal knowledge.

 

This has already yielded a range of dramatic new treatments, and sent

experts back to the kitchen gardens.

 

Plants from the allium family - garlic, leeks, onions - have been

traditionally used to treat gastroenteritis, high blood pressure and

other conditions.

 

Field Hospital is part of the Go Wild summer festival at Kew, sponsored

by GlaxoSmithKline. It will run from May 24 to September 28

 

Aspirin, acetylsalicylic acid, marketed by Bayer in 1889 - but

meadowsweet was used to treat pain and fever for centuries

 

Quinine bark from the Cinchona ledgeria tree in Peru was known as

Jesuit's powder 300 years ago. Used to combat malaria

 

Atropine, from Atropa belladonna, is important in ophthalmology

 

Digoxin, from digitalin. Folk healers used foxglove or Digitalis

purpurea (left) to treat dropsy

 

Morphine, the powerful analgesic from the opium poppy Papaver somniferum

 

Reserpine from Rauvolfia serpentina, used in the Himalayas as an

antidote to snakebite, became the world's first hypertension drug 50

years ago

 

Vincristine and vinblastine treat childhood leukaemia and Hodgkin's

disease. Both came from Catharanthus roseus in the 1980s

 

THC from Cannabis sativa, known as a medicinal aid for 2,000 years, is

being tested to relieve multiple sclerosis

 

Guardian Unlimited © Guardian Newspapers Limited 2003

 

Donadaghovi AiSv Nv wa do hi ya do

(Til next we meet, Walk in Peace)

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