NEW YORK -- James Duke is one of those rare botanists who actually eat what they preach.
He loves to watch the evening primrose open in 60 seconds. But he also munches its seeds, which are high in tryptophan, an essential amino acid that can relieve pain and depression.
Purple coneflowers thrive in his rather rumpled and wild Maryland garden -- in Fulton, in south-central Howard County. He eats their roots to boost his immune system.
To cure a cold, he mashes up the stems and leaves of forsythia.
To help strengthen weak capillaries, he makes "rutinade" from violet and buckwheat flowers, lemon grass and rhubarb stalks, and plants high in rutin (anise, camomile, mint, rose hips).
The 62-year-old Dr. Duke, a jungle explorer, a blue-grass bass-player, a punster-poet and a writer-researcher for the U.S. Department of Agriculture, was one of four scheduled speakers at a daylong symposium yesterday on "Plants for Health and Healing: Their Role in Modern Medicine" at the New York Botanical Garden in the Bronx.
As both an economic and an ethnobotanist, Dr. Duke is well versed in the monetary value and folk use of plants. He lectures on the disease-fighting power of phytochemicals found in everything from soybeans to licorice root and pansies, which he ate all summer to counteract anti-inflammatory drugs he took most of this year for a slipped disk and a later back operation.
He is collaborating with the National Cancer Institute on both its AIDS and cancer-screening programs and its $20 million "designer food" program to prevent cancer.
Spring finds him wandering the woods outside the Agriculture Department office in Beltsville ("known only to bikers and weird botanists," he says) for wild ginseng.
And in fall, pruning yew bushes. "The seeds are poisonous, so you have to be careful not to swallow them," he said, picking a few red berries from his own shaggy hedge at home. He popped them into his mouth and spat out the seeds. "The pulp doesn't have much taxol," he said, "but the needles may have as much as 100 parts per million taxol."
Taxol, an anti-tumor agent, may prove a powerful treatment for advanced ovarian cancer, and it shows promise against breast and lung cancer.
The Agriculture Department is harvesting the Pacific yew in the Northwest, and the Food and Drug Administration has permitted Bristol-Myers Co. to manufacture taxol from the bark and use it experimentally. But the forest is already threatened by overlogging.
So here's this resident witch doctor for the establishment, who says taxol is staring us in the face in our own backyards. He recently cut a branch from a yew on the Agriculture Department's grounds and sent it to the Cancer Institute for analysis.
"The needles had 80 parts per million of taxol," he said. "There's no reason to kill those trees out West when we can just give our hedges a haircut."
Of Dr. Duke's yew specimen, Dr. Kenneth Snader, a chemist at the institute, said: "It's a very useful addition to our search." But, he added, "I'm not convinced it's going to replace other programs."
Dr. Duke has long wandered through the rain forests of South America, observing which leaves and roots the natives use against disease, then using them himself.
In the late 1950s, he explored Peru and Panama for the Missouri Botanical Garden. But it was a three-year stint in Panama for Battelle-Columbus Laboratories of Columbus, Ohio, in the early 1960s, that most impressed the young researcher from the University of North Carolina.
"The Atomic Energy Commission had hired Battelle to predict what radioactive materials would end up in the food chain if we dug a canal with nuclear devices," Dr. Duke said in his Alabama drawl. "So they sent me down there to figure out everything everybody was eating."
He lived in the forests and traveled up and down the rivers. He watched native fishermen mash up clibadium, which is in the daisy family, and throw it in pools of water to stun their catch. "They'd just float to the top and could be easily picked out by hand," Dr. Duke said.
He was also impressed with a relative of the black pepper family that eased his own toothache.
But these days Dr. Duke is concentrating on familiar plants close to home. The common soybean, for instance.
"The isoflavones in soybeans have the most promising potential for arresting breast cancer," said Dr. Duke, who has helped the Cancer Institute focus on the most potent of the 10,000 soybean varieties. But drug companies, he said, don't want to know that plain old plants can cure disease.
"If you and I go around sucking on licorice root, which can guard against ulcers, that's not going to make any money," he said. "No drug company wants to prove feverfew will prevent migraines, if they make $2 billion a year off migraines." Feverfew is a herb.
Dr. Herbert Pierson, a toxicologist at the Cancer Institute, agrees. "Every prescription drug that's making a profit has a patent on how it's synthesized or formulated in a dosage form," he said. "There's not much financial interest in something that we can grow on a windowsill."
Which is one reason the institute is pursuing its $20 million "designer food" program. If scientists can identify the most powerful disease-fighting components of plants, these phytochemicals can be used to fortify food.
On several afternoons, Dr. Pierson has trailed after Dr. Duke, crushing up wild garlic mustard and eating the buds of tiger lilies.
"They look like miniature bananas and have a sweet, nutty flavor," Dr. Pierson said. Like many flowers, they are high in the substances that strengthen cell membranes.
"He actually practices what he preaches," Dr. Pierson said. "Nobody should underestimate his knowledge. He knows from folkloric use that these things aren't used by chance, that they've survived the test of time."
Dr. Duke has written 10 botanical manuals, 200 scientific papers and two popular books on the medicinal uses of plants: "A Field Guide to Medicinal Plants," (Houghton Mifflin, 1990), written with Steven Foster, and "CRC Handbook of Medicinal Herbs" (CRC Press, 1985).
Now he is working to complete an electronic data base that cross-references the nutrients and chemical constituents, ecology and folk uses of 1,000 plant species.
Dr. Pierson said that this "is going to be one of the most useful tools for the health food industry and interested pharmaceutical companies, because nobody else has taken the time to go through the massive amount of information and put it in a user-friendly form."