JERUSALEM — Roots, berries, leaves, resins, twigs and flowers have not only healed us for thousands of years past, they have also led scientists to many modern drugs. Foxgloves, willows and poppies may look therapeutically unpromising in the garden, but digitalis first came from the foxglove, aspirin from willow bark and a range of opiates from the poppy.

These are just three in a medicine chest bulging with drugs from natural sources –from antibiotics (first identified in fungi), through synthetic tranquilizers (resperine originated in a Nigerian root used to cure moon madness) to the powerful anti-cancer drugs, vincristine (from the Madagascar periwinkle) and taxol (from Pacific yew bark).

It's only during the past half-century, in fact, that the old plant-and-water therapies have been swept away in a tidal wave of modern medical skepticism. But the pendulum is swinging back with researchers and pharmaceutical companies today researching traditional remedies with increasing enthusiasm — and often finding new bases for effective modern drugs.

"Israel has some 3,000 different native plant species, many of them with long traditions of medicinal use among Bedouin, Druze, Galilee Arabs and Middle Eastern Jewish communities," says Dr. Sarah Sallon, head of the Natural Medicine Research Unit at the Hadassah-Hebrew University Medical Center in Jerusalem. "Fragrant star and red doc, for example, are believed by traditional healers to have a positive effect on cardiac activity. Like 90 percent of Israel's plants, however, they have never been scientifically tested."

The natural medicine unit was founded seven years ago to explore what Sallon believes is a treasure house of native and folk medicines. "We're working with Hebrew University's National Herbarium to compile a database of the region's medicinal plants, along with their disappearing healing traditions," she says. "This will form a basis for scientific examination of their healing properties."

Much of traditional Bedouin medicine has already been preserved, with the recent publication of a book by Dr. Aref Abu Rabia, a Bedouin who is an anthropologist and lecturer in Ben-Gurion University of the Negev's Middle East studies department. Saved as a child by a Bedouin healer, he has spent 25 years studying Bedouin folk medicine. "For kidney problems alone, there are 15 natural treatments, utilizing everything from herbs to sheep or goat gallbladder," he says.

Some natural remedies, however, are more appetizing than ungulate organs. Three simple glasses a day of freshly squeezed orange juice can inhibit the build-up of fatty plaque that clogs arteries, leading to heart attacks and strokes, according to a discovery by Professor Elliot Berry of Hadassah's human nutrition and metabolism department. His research was the first to show a clear effect of vitamin C on levels of low-density lipoprotein (LDL).

If you don't care for orange juice, try chewing on licorice root (the real thing that contains glabridin, not the watered-down candy sold over the counter). Michael Aviram, professor of biochemistry and medicine at the Technion-Israel Institute of Technology in Haifa, has shown glabridin to be another stalwart defense against LDL.

Want to fight off infection naturally? The fruit bowl may be a large part of the answer. Cranberry juice, folk medicine's favorite remedy for urinary tract infections, received its first scientific validation at the Weizmann Institute of Science in Rehovot, when molecular biologist Professor Nathan Sharon showed it prevents key bacteria from sticking to the urinary tract. Probably the only effective flu remedy on the market also comes from fruit — in this case, the black elderberry. Its secrets were unraveled at Hadassah by virologist Dr. Madeleine Mumcuoglu, and it is now sold worldwide as Sambucol.

Or perhaps you prefer pomegranates. Technion researchers Professor Ishak Neeman, Shai Schubert and Ephraim Lansky have found their high levels of antioxidants combat atherosclerosis, inflammation and cancer, and as well as delay cellular aging processes.

Vegetables have as much to offer as fruit. Garlic has long been known to pack a powerful punch against infection, and Professors David Mirelman and Meir Wilcheck of Weizmann's biological chemistry department have found out why. Its main component, allicin, disables two groups of enzymes needed by bacteria and viruses to invade cells, giving it potential as a broad-spectrum anti-microbial drug.

Cabbage, broccoli and radishes seem linked with lower incidence of breast cancer, according to Professor Shmuel Yanai of the Technion's faculty of food engineering and biotechnology. And epidemiological data show lower incidence of breast cancer in women who eat a lot of tomatoes, says Dr. Michael Koretz, director of Ben-Gurion University's Elisheva Eshkol Breast Health Center.

The medicinal properties of seaweed have long been vaunted, especially by coastal peoples. Professor Shoshana Arad of Ben-Gurion University's Applied Bio-Sciences Institute has taken a closer look, extracting a polysaccharide from the cell walls of red microalgae and developing from it the first natural, effective topical anti-viral treatment for herpes. In vitro experiments at the Pasteur Institute in France showed it to perform more effectively than the principal synthetic medication currently used to treat herpes lesions. Arad is now testing the anti-inflammatory properties of the polysaccharide as a treatment for reducing friction in joints.

Arad's colleagues at Ben-Gurion and Soroka University Medical Center are studying replacement of living bone with coral, which is absorbed by the surrounding tissue, forming regenerated bone. The researchers have recently identified a new coral species less brittle than other species, making it especially suitable for replacing load-bearing bone.

Perhaps the most comprehensive study of natural medicine currently under way in Israel, however, has nothing to do with local herbs, fruits, vegetables or corals. It is a scientific examination of Tibetan medicine, the ancient system of herbal healing whose secrets were, until recently, closely guarded by the monk-doctors who dispensed it.

"We've made and used our medicines for 2,000 years," says the Dalai Lama, who has visited Hadassah's Natural Medicine Research Unit twice during the six years of research. "We know they work. But our recipes are not understood in the West because they're not in the language of modern science."

Energetically encouraged by Sallon, Hadassah researchers are working on the translation. The first remedy they investigated is used in Tibet for "a condition resulting from excess heat energy," attributed to an excess of yak and other red meat, fats and alcohol. Israeli doctors read this as atherosclerosis (whose causes include smoking, overweight and elevated levels of cholesterol and other fatty substances in the blood), and launched a three-year study of 80 elderly patients with painfully clogged arteries in their legs.

Vascular surgeons Professors Yaakov Berlatzky and Dr. Gidon Be'er have shown not only that the Tibetan remedy is effective according to objective measurable parameters, but also that it works because it is a powerful antioxidant that mops up excess free radicals that contribute to aging, tissue injury and inflammation. It also seems to interfere with the formation of harmful fat layers in blood vessels. Hadassah researchers are now examining whether it may help patients with heart and fertility problems.

Another study concerns a Tibetan bowel tonic. "Western medicine doesn't have any concept of bowel tonic," says Sallon, "but we've recently completed a study of this medicine in people with irritable bowel syndrome — a complaint accounting for around 70 percent of gastroenterology consultations. Our results are very encouraging." So heartened are the Hadassah researchers that the rare Tibetan herbs needed for the remedies are now being grown in the Negev at Kibbutz Ketura.

From herbs to pomegranates, from goat gallbladders to corals, a wealth of cures exists in nature. Increasingly, Israeli researchers are tracking them down and unraveling their chemical codes in the heartfelt hope of putting better, easier and faster medicines onto pharmacy shelves.