White fungi on decaying log in Manu National Park, Peru. (Photo by R. Butler)
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MEDICINAL PLANTS
Plants have broader uses than as just food and a genetic reservoir. Increasingly, rainforest plants, and to a lesser
extent rainforest animals, are the source of compounds useful for medicinal purposes. The rainforest has been
called the ultimate chemical laboratory with each rainforest species experimenting with various chemical defenses
to ensure survival in the harsh world of natural selection. They have been synthesizing these compounds for millions
of years to protect against predators, infection, pests, and disease. This makes rainforest species an excellent
reservoir of medicines and chemical templates with which researchers can create new drugs.
Rainforest plants have already provided tangible evidence of their potential with remedies for all sorts of medical
problems, from childhood leukemia to toothaches. Seventy percent of the plants identified as having anti-cancer characteristics
by the US National Cancer Institute are found only in the tropical rainforest. Some examples of rainforest plants
responsible for 25 percent of the drugs used by Western medicine are included
in this table.
Despite all their promise, fewer than 5 percent of tropical forest plant species (and 0.1 percent of animal species) have been
examined for their chemical compounds and medicinal value. Once a plant with the desired qualities is discovered,
it is rigorously analyzed for its chemical structure, then goes through clinical trials for effectiveness and safety before
getting final approval from the US FDA. Nevertheless, using rainforest species for derivation and synthesis of
medicinal compounds, is becoming a mainstream process. In 1983 there were no U.S. pharmaceutical firms involved
in research on such plants. Today there are well over 100 corporations, and U.S. government agencies are studying
rainforest plants for their medicinal capacities.
One such organization, the U.S. National Cancer Institute, maintains screening of rainforest species for anti-cancer
and anti-HIV
effects. Because there are so many plant species, institute researchers concentrate on close relatives of plants
already known to produce useful compounds. Another method is to choose plants that display characteristics indicating
they have an effect on animals, like deterring insect pests. Many chemicals toxic to insects show bio-activity
in humans meaning they may have drug promise.
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RELATED ARTICLES
Amazon rainforest children to get medicinal plant training from shamans 11/21/2007
The Amazon Conservation Team (ACT) -- a group using innovative approaches to preserving culture and improving health among Amazonian rainforest tribes -- has been awarded a $100,000 grant from Nature's Path, an organic cereal manufacturer. The funds will allow ACT to address one of the most pressing social concerns for Amazon forest dwellers by expanding its educational and cultural "Shamans and Apprentice" program for indigenous children in the region.
7-year old nature guide becomes Belize environmental hero as adult 11/16/2007
Each year hundreds of thousands of nature-oriented tourists visit Belize to see the Central American country's spectacular coral reefs, biodiverse rainforests, and ancient Mayan ruins. However few visitors realize that Belize's natural resources are at risk. Timber and oil extraction, agricultural encroachment, coastal development, pollution and unrestrained tourism are all increasing threats to Belizean ecosystems. Unless something is done to address these concerns, within a generation these pressures could present considerable problems for Belize. Dr. Colin Young, head of the environmental science program at Galen University in Belize, says that while he is greatly concerned about these issues, there is still time to ensure healthy forests and reefs in Belize
70% of new drugs come from Mother Nature 3/20/2007
Around 70 percent of all new drugs introduced in the United States in the past 25 years have been derived from natural products reports a study published in the March 23 issue of the Journal of Natural Products. The findings show that despite increasingly sophisticated techniques to design medications in the lab, Mother Nature is still the best drug designer.
Indians are key to rainforest conservation efforts says renowned ethnobotanist 10/31/2006
Tropical rainforests house hundreds of thousands of species of plants, many of which hold promise for their compounds which can be used to ward off pests and fight human disease. No one understands the secrets of these plants better than indigenous shamans -medicine men and women - who have developed boundless knowledge of this library of flora for curing everything from foot rot to diabetes. But like the forests themselves, the knowledge of these botanical wizards is fast-disappearing due to deforestation and profound cultural transformation among younger generations. The combined loss of this knowledge and these forests irreplaceably impoverishes the world of cultural and biological diversity. Dr. Mark Plotkin, President of the non-profit Amazon Conservation Team, is working to stop this fate by partnering with indigenous people to conserve biodiversity, health, and culture in South American rainforests. Plotkin, a renowned ethnobotanist and accomplished author (Tales of a Shaman's Apprentice, Medicine Quest) who was named one of Time Magazine's environmental "Hero for the Planet," has spent parts of the past 25 years living and working with shamans in Latin America. Through his experiences, Plotkin has concluded that conservation and the well-being of indigenous people are intrinsically linked -- in forests inhabited by indigenous populations, you can't have one without the other. Plotkin believes that existing conservation initiatives would be better-served by having more integration between indigenous populations and other forest preservation efforts.
Anti-HIV drug from rainforest almost lost before its discovery September 13, 2005
Rainforest plants have long been recognized for their potential to provide healing compounds. Indigenous peoples of the rainforest have used medicinal plants for treating a wide variety of health conditions, while western pharmacologists have derived a number of drugs from such plants. However, as forests around the world continue to fall—the Amazon alone has lost more than 200,000 square miles of forest since the 1970s—there is a real risk that pharmaceutically-useful plants will disappear before they are examined for their chemical properties. Increasingly, it is becoming a race against time to collect and screen plants before their native habitats are destroyed. One near miss occurred recently with a compound that has shown significant anti-HIV effects.
Medicinal powers of plants explored at San Francisco Conservatory of Flowers September 6, 2005
Plants have long been used by humans for treating a wide range of ills, from childhood leukemia to hangovers. Indeed, many of the pharmaceuticals currently available to Western doctors have a long history of use as herbal remedies, including quinine, opium, aspirin, and coca. Many of the most promising plants are found in the world's tropical rainforests which house perhaps 50 percent of the biodiversity on the planet. These ecosystems are increasingly threatened by deforestation, and examining these forests before they are further destroyed has become a top priority for pharmacologists.
Drugs derived from chocolate? Candy-maker Mars in talks July 25, 2005
Mars, Incorporated, the privately held U.S. company that produces M&Ms, Twix, Snickers and other confections, is in talks with several large pharmaceutical companies to develop medications based on flavanols—plant chemicals with health benefits like those found in cocoa, according to a report from Reuters.
Rainforest plant helps treat psoriasis July 14, 2005
A compound derived from an Amazon-rainforest tree is effective in the treatment of the skin disease psoriasis, according to a study released in late June in the Journal of the Federation of American Societies for Experimental Biology.
How did rainforest shamans gain their boundless knowledge on medicinal plants? The short answer—no one really knows May 14, 2005
Ethnobotanists, people who study the relationship between plants and people, have long been aware that rainforest dwellers have an astounding knowledge of medicinal plants. For thousands of years, indigenous groups have used rainforest plants extensively for their health needs—the peoples of Southeast Asian forests used 6,500 species, while Northwest Amazonian forest dwellers used 1,300 species for medicinal purposes. Today pharmacologists and ethnobotanists work with native healers and shamans in identifying prospects for development of new drugs.
Shamans and Robots: Bridging the Past and Future of Ethnobotany and Bioprospecting April 25, 2005
Since very early in human history, people have relied on medicinal plants to cure them of their various ills. Ethnobotany is the study of plant lore and agricultural customs of a people and is progressively being explored by pharmacologists for the development of drugs. Given their extensive range of knowledge of medicinal plants, indigenous people have traditionally been the ultimate resource for retrieving this information for purposes of application to modern medicine—the medicinal value of plants is very significant—and no more so than today. Tropical rainforests are particularly endowed with plants possessing curative properties. These richly biodiverse environments provide a veritable trove of flora containing compounds of medicinal value, which indigenous people have utilized and benefited from for centuries.
Coral, Coiba and the Next Big Thing. Bioprospecting in Panama April 20, 2005
The largest island off the Central American Pacific coast may be hiding big secrets in its reefs, among them a possible cure for malaria. Coiba, an island 12 miles off the coast of Panama and once a notorious penal colony, is poised on the brink of transition and transformation. The 10-mile wide and 30-mile long island possesses a unique ecology that may host potential drugs for treating numerous ills. The future of Coiba depends on how its resources are managed by the government.
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Indigenous uses of plants can also offer hints of potentially useful plants. For thousands of years, indigenous
groups have extensively used rainforest plants for their health needs. They have experimented with a wide range
of plants. The peoples of Southeast Asian forests used 6,500 species, while Northwest Amazonian forest dwellers
used at least 1,300 species for medicinal purposes. The success rate for discovering medicinal plants with traditional uses
is high because rainforest peoples, notably shamans, have been experimenting with various combinations and dosages
for generations. A recent study in Samoa found that 86 percent of the plants used by local healers yielded biological
activity in humans.
The National Cancer Institute can rapidly screen compounds for activity against 60 cancer types. When the compound
shows promise, chemists isolate the molecules responsible for the activity and then compare the molecular structure
with that of known chemicals. Sometimes the molecule already has been identified, but is not used medicinally;
at other times the molecule will be altered to produce the desired action. If the molecule has potential as a drug,
it is tested for certain characteristics including safety, effectiveness, and side effects. If it passes those
tests, a corporation or government agency must finance bringing the drug to market—a process that costs more than $800 million and may take 12 years. Before reaching the public market, the drug must go through rigorous clinical trials. According to the Global Bioscience Development Institute, for every 10,000 to 20,000 compounds screened for possible activity in the basic-research stage, about 250 make it as far as pre-clinical testing. Of those, five drug candidates make it as far as clinical trials, and only one becomes an actual FDA-approved drug. Thus the process of bringing a rainforest drug, or any pharmaceutical product, to
market is long and costly.
Nevertheless, commercial sales from such drugs typically take in huge sums: the two chemicals derived
from rosy periwinkle bring in revenues of US$160 million per year. Large companies usually benefit the most from
such projects while the local peoples and shamans get little in return. For example, virtually no money from the vincristine
and vinblastine derived from the rosy periwinkle made it back to the country of origin, Madagascar. However, once
the drug patent expired, Madagascar was able to begin exporting tons of crude periwinkle annually.
In the past such exploitation, known as biopiracy, was the rule. While drug companies raked in millions in revenue,
the community that found the plant producing the drug was left with token baseball hats, beads, or aspirin as compensation.
One of the biggest biopiracy coups occurred last century when the British smuggled (at least Brazilians allege)
rubber tree seeds out of Brazil to their colony of Malaysia, ending the lucrative Amazonian monopoly on rubber.
Recently a bitter patent battle has erupted between the Inter-American Foundations, a U.S. development agency, and
COICA, an organizations representing indigenous peoples from the Amazon region, over ayahuasca or yagé.
Yagé is a celebrated hallucinogenic, derived from a rainforest liana and other plants, which is used ceremonially
by Amazonians. The biopiracy incident was initiated in 1986 when an American visiting Ecuador took a sample of
yagé without permission and acquired a patent from the U.S. government. Today the American has started the
International Plant Medicine Corporation and is working with yagé to develop psychiatric and cardiac pharmaceuticals.
COICA says the American has no right to patent, without permission, a plant compound that has been used for generations
by indigenous peoples. Complicating the debate is the refusal of the U.S. Senate to ratify the UN Convention on
Biodiversity, which has been ratified by more than 100 countries including Ecuador, where the Yagé sample
was acquired. The UN agreement includes the recognition of intellectual property rights of indigenous peoples.
This exploitation without compensation has been the trend, although today more of the revenues are returned to the indigenous peoples.
Most tropical countries are ill-suited for the analysis of species for medicinal value and lack the funds to sponsor
such activities, so drug research and development will likely continue to be dominated by industrialized countries.
However compensation for the country of the product's origin must be addressed if the source of these products
—the tropical rainforest—is to be preserved.
Several pharmaceutical companies have agreed to share revenues with local people. The drug Prostialin, isolated
in 1984 from a Samoan rainforest tree, has exhibited strong activity against HIV in tests. With its discovery,
the National Cancer Institute has guaranteed that part of the royalties from the sale of the drug will be returned
to the Samoans. As a result the fiftieth national park of Samoa has been established to encourage local healers
to use medicinal plants in a sustainable way, in order to pass their knowledge on to the next generation. Similarly,
in 1991, Merck and Company invested $1 million in Costa Rica's INBIO project to assist in a cataloging
and screening effort. The institute will collect and identify organisms, sending samples from the most promising
species to Merck laboratories for medicinal assay. If the compounds prove useful and the resulting drugs make it
to market, the Costa Rican government is guaranteed some of the royalties, which will be set aside for conservation
projects. A similar agreement is in the works between Bristol-Myers Squibb and the government of Suriname.
Review questions:
- Why are plants a good source for medicines?
- What is biopiracy?
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WEEKLY NEWSLETTER
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Recent news
Zoopharmacognosy: how self-healing animals could save humans
(11/27/2011) As humans we take many things for granted. When we come down with a sore throat, a fever, or the dreaded stomach flu, we drag our aching bodies into our cars and visit the doctor. Animals have no such luxury. Instead they have mastered evolution and have acquired an innate knowledge of the plants, soils, minerals, algae, and other remedies that nature offers to heal their aches and pains.
Chemotherapy tree facing extinction
(11/10/2011) A yew tree in the Himalayas that produces the chemotherapy drug, Taxol, is in danger of extinction. An update to the IUCN Red List, has moved the tree, named Taxus contorta, from Vulnerable to Endangered. Overharvesting for medicine and fuelwood have placed the species in serious danger.
Shamans and indigenous spiritual leaders unite in Malibu
(11/09/2011) Just north of Los Angeles on a bluff overlooking the Pacific Ocean is a special piece of ancient tribal land. Prehistoric artifacts and burials indicate that occupation occurred there as early as 6000 BC. It was this primeval site on a crisp October night recently where the Wishtoyo Foundation and the Chumash people, in cooperation with the Amazon Conservation Team, held 'A Summit of Indigenous Spiritual Leaders.'
Monarch butterflies medicate their sick kids
(10/12/2010) A new study in Ecology Letters has discovered that monarch butterflies employ medicinal plants to treat their larva. Researchers found that certain species of milkweed, which the larva feed on, can reduce the threat of a sometime deadly parasite. However, even more surprising: "we have also found that infected female butterflies prefer to lay their eggs on plants that will make their offspring less sick, suggesting that monarchs have evolved the ability to medicate their offspring," says lead author Jaap de Roode.
Losing nature's medicine cabinet
(10/04/2010) In all the discussions of saving the world's biodiversity from extinction, one point is often and surprisingly forgotten: the importance of the world's species in providing humankind with a multitude of life-saving medicines so far, as well as the certainty that more vital medications are out there if only we save the unheralded animals and plants that contain cures unknown. Already, species have provided humankind everything from quinine to aspirin, from morphine to numerous cancer and HIV-fighting drugs. "As the ethnobotanist Dr. Mark Plotkin commented, the history of medicine can be written in terms of its reliance on and utilization of natural products," physician Christopher Herndon told mongabay.com. Herndon is co-author of a recent paper in the journal Biotropica, which calls for policy-makers and the public to recognize how biodiversity underpins not only ecosystems, but medicine.
More news on medicinal plants
More rainforest news
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