Guides Information

Nature's Pharmacy: The Healing Power of Plants
Explore the fascinating link between plants and our health

This is an overview of the plants featured on the graphic panels of the exhibit.

Throughout history, people have relied upon plants to prevent illness and heal disease. Today, close to 75 percent of the world population continues to rely solely on plant-based remedies as their primary medicines. In the United States alone, doctors write 12.5 million prescriptions a year for plant-based drugs.

Whether it's ancestral herbal remedies or patented pharmaceuticals, plants play a vital and often overlooked role in human health.

Despite the enormous number of plant-based drugs in use, less than 20 percent of earth's plant species have been examined for their healing abilities. More than 200,000 plant species await discovery.

The purpose of this exhibit is to raise awareness about the everyday plant based health remedies we rely on, and the thousands that have yet to be researched. The dilemma is global: what are we losing when either indigenous plants or the knowledge of how to use them becomes extinct?

AFRICA

The lush forests and sweeping grasslands of Africa are full of potential medicinal plants. This vast continent has provided Western medicine with a few plant-based drugs but its unique medicinal plants have yet to be fully explored.

A sampling of healing plants in use include:

Aloe vera, Aloe barbadensis
Evolved in Africa, aloe's medicinal properties were recognized at least 3,500 years ago by the ancient Egyptians. For centuries, aloe gel has been used to treat first-degree burns from the sun and in the kitchen. It has a cooling quality and us useful for soothing digestive troubles. Currently, scientists are researching its use to combat AIDS, to manage diabetes, treat leukemia and other types of cancer.

Aspilia, Aspilia mossambicensis
Traditional uses include treatment for lumbago, sciatica, malaria and tuberculosis. Its hairy leaves remove worms from the intestines as the leaf passes through the digestive system. Aspilia may be effective against lung and breast tumors.

Bitterleaf, Vernonia amygdalina
Used in soups, stews, eaten raw as a green and dried for use as a culinary herb, it is also used to treat fever, intestinal complaints and malaria. New uses include antiparasitic, antitumoral and antibacterial applications. Research is underway exploring its potential to fight breast cancer and diabetes.

Calabar bean, Physostigma venenosum
In traditional medicine it is used to fight rheumatism, ringworm and other diseases. Today, it is used to treat glaucoma, and is used in the manufacture of synthetic progesterone.

Strophanthus, Strophanthus gratus
The ripe seeds were used as a poison on arrows and spears. Now it is used as a cardiac stimulant in emergency cases.

Uzara, Xysmalobium undulatum
The dried roots are used as a remedy for diarrhea.

Yohimbe, Pausinystalia johimbe
The bark is used as a stimulant, to regulate urination, and as a male tonic. There are many over-the-counter products promising to cure male impotency made from yohimbe available in the US. The FDA has approved a yohimbe-based drug for the treatment of the problem.

Learning from Animals, too.

While Africans have longed used bitterleaf and aspilia, researchers have discovered that animals use them too. Chimpanzees suffering from parasitic infections suck the bitter juice from the pith of the young vernonia shoots and typically show improvement in less than 24 hours.

When chimps are infected with a different parasite, they were found to rely on aspilia for a cure. These sick chimps carefully remove one rough, thorny aspilia leave at a time, folding it accordion-style. Each folded leaf is swallowed whole and physically removes the worms using the leaf's tough hairs as barbs as it passes through the chimps' intestines.

NORTH AMERICA

Native Americans have known for centuries which plants have medicinal properties and how to combine them to make more potent remedies. There's a wealth of information in old books which describe the medicinal properties of plants and herbs. These herbals date back some 500 years to the first European settlers, who learned about North American plants form the Native Americans.

Native North American medicinal plants include:

American ginseng, Panax quinquefolius
Stimulates cardiovascular and central nervous systems, lowers blood sugar, strengthens the immune system and helps treat diabetes. It may have antioxidant, antiaging and appetite-stimulating properties.

Devil's club, Oplopanax horridus
All parts of this plant have long been used by the Native peoples along the coast of British Columbia and Alaska to treat everything from coughs and colds to stomach complaints. It is of huge medicinal importance to people from the region. Today researchers are studying its effectiveness in the fights against tuberculosis and non-insulin dependent diabetes.

Echinacea, Echinacea angustifolia, Echinacea purpurea
This was the primary cold and flu remedy in the US until 1940. Traditionally it was used to treat snakebites, toothaches, burns, colds and throat infections. It was the Plains Indians' basic medicine.

Evening primrose, Oenothera biennis
Has been used for diabetes, dermatitis and rheumatoid arthritis. Containing essential fatty acids, it's used for hormonal balance and in the relief of symptoms of menopause. Evening primrose supports the production of prostaglandins which help maintain hormonal balance in women with PMS.

Goldenseal, Hydrastis canadensis
Goldenseal is traditionally used to treat wounds, ulcers, skin and eye ailments. It has proven antibiotic, antibacterial and antifungal properties. A plant antibiotic, it should be treated with the same respect held for pharmaceutical antibiotics-it kills both good and bad bacteria, and should be used for a limited time only.

Marijuana, Cannabis sativa
First documented use was 4,000 years ago in ancient China and India. Marijuana reduces intraocular pressure from glaucoma, relieves nausea and reduces unpleasant effects of cancer chemotherapy.

Pacific yew trees, Taxus brevifolia
The cancer-fighting drug paclitaxel was originally isolated from the bark of these trees. Stripping the bark meant killing the trees. Now, drug manufacturers are producing plant cell cultures from which they can extract the paclitaxel, saving the trees.

Too popular for their own good?

In the US, medicinal herbs harvested in the wild are often worth three times as much as farmed roots which often entails high pesticide use to control diseases. Unfortunately, the increasing popularity of the wild-grown herbs is threatening the existence of these herbs, like goldenseal and American ginseng, whose natural production can not keep up with consumer demand. Research efforts are underway to learn to cultivate them in a healthier manner before these plants disappear.

ASIA

The incredibly varied ecosystems on the Asian continent provided myriad plants for early healers to experiment with. For centuries, these healers wrote down what they learned and these ancient records formed the basis of the traditional medicine practiced all over the world today.

A sampling of Asian plants relied upon:

Astragalus, huang qi, Astragalus membranaceus
Supports T-cell function and stimulates immune system. It has traditionally been used for compromised immune systems, viral infections and high blood pressure. Documents show that it was in use more than 2,000 years ago in China.

Dong quai, Chinese angelica, Angelica sinensis
The roots and rhizomes are used to treat rheumatic pain, abdominal pain, headaches; balance the female hormone system; also as a blood purifier and to treat rheumatism, ulcers and hypertension

Epehdra, Ephedra sinica
A native to the deserts of Northern China and Mongolia, edphedra-based drugs appear in 200 or so drugstore remedies, including pseudoephedrine or SudafedÒ. It has a long history in treating asthma and other bronchial ailments. An ephedra-based weight loss product was recently banned because users who overdosed died.

Ginger, Zingiber officinale
A kitchen favorite, ginger also treats motion sickness, vertigo, indigestion, flu, colds and arthritis; soothes abdominal cramps. With its warming quality, ginger has traditionally been used for colds, fever, tetanus and leprosy. It has a long history of use in treating morning sickness. It's first documented use was 5,000 years ago in China.

Ginkgo, Ginkgo biloba
In use for at least 2,800 years in China, ginkgo is known to increase the circulation. It increases cognitive functions in elderly people delaying the progression of Alzheimer's disease, increases blood flow to the legs, thins blood; treats tinnitus of a circulatory origin, depression and asthma. This ancient tree is also used to prevent memory loss.

Happy tree, Camptotheca acuminata
For centuries, the Chinese xishu, or "Happy tree", has been used to treat colds, psoriasis and disease of the stomach, spleen, liver and gall bladder. Thirty years ago, it was discovered that one of the tree's chemical components, camptothecin, is a powerful anti-cancer drug and a precursor to several more.

Camptothecin was originally extracted from the wood, bark or seeds of the tree. While the seeds are a sustainable source, the trees were cut down to get the wood and bark. Researchers have since found that the young leaves of this tree also contain fairly high concentrations of the drug. Growers can clip the leaves at their peak potency and the trees can go on to grow another crop.

Opium poppy, Papaver somniferum
Opium has been harvested from poppy plants for centuries. From opium come morphine, a pain reliever; codeine and noscapine, cough suppressants; and papaverine, an antispasmodic and cerebral vasodilator. Heroin is an illegal street drug that also comes from opium.

Afghanistan grows about 75 percent of the world's illegal opium supply according to the UN Office on Drugs and Crime. Controlling this source involves changing the attitudes of people used to the quick profits of drug trafficking and providing them with another source of income.

In 2000, farmers in India were paid approximately $13.00 for 2.2 pounds of raw opium by the Central Narcotics Bureau officials who send it to government-run factories for drying and export. The black market paid up to 25 times that much.

SOUTH AMERICA

Logging, mining and agribusiness are changing the face of South America. As the rainforests are cut and the pampas converted to cattle pens, the world is losing more than just these unique ecosystems.

Western ways of eating, healing and making a living are replacing native cultures and traditional ways. With no one interested in their services, healers and shamans stop collecting plants and making medicines. What's worse, they find no one to pass their knowledge on to.

Coca, Erythroxylum coca
The source of cocaine, coca has been used in healing since pre-Incan times. It was traditionally used to relieve hunger, fatigue and altitude sickness. Today, it is used as a non-addictive topical anesthetic applied to mucous membranes, and in a mixture of drugs to control pain from terminal cancer. Coca was the molecular model for synthetic drugs including Novocaine.

Guaiacum, Guaiacum officinale
Relied upon in pre-Columbian South and Central America, guaiacum was used for rheumatoid arthritis, respiratory problems, gout and skin disorders. It is used as an anti-inflammatory, local anesthetic and herpes treatment.

Ipecac, Psychotria ipecacuanha
Currently used as an emetic, and antiamoebic, it's traditional uses include as a treatment for gastrointestinal diseases, diarrhea, intermittent fevers, bronchitis, bronchopneumonia, asthma and mumps.

Cayenne, Capsicum frutescens
The first documented use of cayenne was at least 500 years ago by the Aztecs. Historically, it has been used to treat dyspepsia, colic and chronic laryngitis. Currently, it's used to relieve pain from diabetic neuralgia, osteoarthritis, rheumatoid arthritis. Research is underway for its potential use on cluster headaches.

Curare, Pareira, Chondrodendron tomentosum, is a vine that grows in the tropical and subtropical rainforests of South and Central America. Amazonian tribes make curare, a deadly arrow poison, from the bark. Western medicine makes d-tubocurarine which enhances general anesthesia. Without it, open-heart surgery would be impossible.

Quinine, Cinchona officinalis
Cinchona, or Peruvian bark as it was called, produces a chemical called quinine that reduces fevers and combats the parasites that cause malaria. Quinine was the first line of defense against malaria until the development of synthetic drugs in the 1940s.

What's Happening to the World's Rainforests?
What Can We Do?

Tropical rainforests cover only 2% of the Earth's surface, yet they are home to over half the plant species on Earth. Tropical rainforests are found along the equator between the Tropic of Cancer in the north and the Tropic of Capricorn in the southern hemisphere. They receive anywhere from 80-100 inches of rain annually (San Francisco receives approximately 21inches per year), maintaining a warm, wet climate year-round-perfect growing conditions for many plants.

The rainforests of the world are being cut down, bulldozed and burned at an incredibly rapid rate--100 acres a minute. That's an area roughly the size of San Francisco destroyed every five hours.

With the destruction of the rainforests and other natural places we could be losing the cure for cancer, diabetes, HIV/AIDS and other diseases. Additionally, with each culture that succumbs to Westernization, we may be losing the native healers who could show us the plants that fight disease.

Seventy percent of the plants identified by the National Cancer Institute as useful in cancer treatment are found only in the rainforest. Drugs used to treat leukemia, Hodgkin's disease and other cancers come from plants found in the rainforest, as do medicines for heart disease, arthritis and birth control. All these medicines despite the fact that we have only examined a tiny fraction of rainforest plants.

The forests are being destroyed primarily by timber, cattle, oil and mining interests. Much of what is produced from the rainforests like paper, furniture, beef and gasoline, end up in the US. We can help save the rainforests by becoming conscientious consumers.

There are a number of things we can do to help the situation:

Use less paper. Many of the trees harvested from the rainforest are used to manufacture paper and paper products. Write on both sides whenever possible, and make scratch pads out of used paper. Always recycle.

Eat less red meat. Much of the meat in fast food, frozen foods and pet food comes from ranches carved out of tropical ecosystems.

Buy shade-grown organic coffee and chocolate. These plantations leave existing trees standing, providing homes for wildlife. Vast acreage of rainforest is cleared to grow non shade-grown coffee.

Recycle aluminum cans to reduce the need for bauxite, the source of aluminum, which is strip mined from tropical countries.

Use less oil products including gasoline and plastic.

Buy only tropical wood products that are certified as sustainably harvested.

Donate money to organizations that protect rainforests and other environments.

Learn all you can about tropical environments and help educate others.

In all things you do, practice the environmentally sound use and reuse of our resources. This will not only have a positive impact on the tropical rainforest but on all the ecosystems of the world.

Web resources

Rosenthal.hs.columbia.edu/Botanicals.html - Columbia University's Rosenthal center for Complementary and Alternative Medicine maintains an exhaustive list of medicinal plant web-based resources

Unitedplantsavers.org - United Plant Savers is a nonprofit dedicated to preserving native medicinal plants of the US and Canada.

Mobot.org/education/tropics/welcome.html - This informative site of the Missouri Botanical Garden is especially focused on plant life in the tropical rain forest: rain forest layers, plant adaptations, plant-animal interactions, economic plants, and biodiversity.