In Bioprospecting Lies a World of Potential

Carlos Bettancurt cuts the motor, and our boat glides soundlessly toward the bank of the Parismina lagoon, part of the wildlife sanctuary at Tortuguero National Park in Costa Rica.

Doused liberally with DEET to ward off mosquitoes and swathed in hats, long-sleeved shirts and pants, we step ashore and follow Bettancurt, a trained Costa Rican naturalist and guide along the path that he cleared in this steamy jungle six years ago. Overhead, a mother white-faced monkey with a baby on her back chatters and swings from tree branches. A beefy two-toed sloth hangs from a tree nearby.

On a sweltering January day, we are hunting not for the elusive jaguars that prowl this nature preserve, but for something more modest: medicinal plants, which grow in abundance in this and other rain forests around the world.

Bettancurt learned about jungle medicine from his grandmother, now in her 90s and unable to accompany us. As we take notes and swat bugs, Bettancurt shows us a platanilla plant, which, when made into a tea, is said to induce abortions. He points out a type of sour cane that is supposed to help with liver and lung problems. And a broom tree, parts of which are said to stop bleeding.

People have always used natural products as medicine, and 80% of those living in developing countries still do. Chimpanzees and other animals eat certain types of foliage when they’re sick that they wouldn’t ordinarily eat as food, says tropical ecologist Dan Janzen of the University of Pennsylvania.

Indeed, about 50% of all pharmaceuticals in use today--from aspirin to cancer chemotherapy drugs such as vincristine and Taxol--are derived from natural sources.

But the modern notion of “bioprospecting” for potential medicines in rain forests, coral reefs, deserts and other exotic locales, began in earnest in 1991, when Merck & Co., the pharmaceutical giant, entered into an agreement with INBIO, Costa Rica’s National Biodiversity Institute, a private, nonprofit group that had been co-founded in the late 1980s by Janzen.

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Under that then-novel agreement, Merck gained access to some plants, fungi and environmental samples from Costa Rica’s protected rain forests, and the Costa Ricans got the right to royalties if any marketed drugs resulted. So far, none have, Merck says, but the company is still analyzing the samples it has collected.

The romantic ideal of bioprospecting gained more steam in 1992, when 177 nations (not including the United States) ratified the Biodiversity Convention, an agreement that outlined ways for rich nations hunting for medicinal gold to share the wealth with cash-poor, plant-rich nations. And, just as important, preserve natural habitats and indigenous populations in the process.

While bioprospecting has not yet yielded any blockbuster drugs, some promising therapies are believed to be in the pipeline. Pharmaceutical companies aren’t saying much about the subject because they don’t want to reveal too much to competitors, says the University of Pennsylvania’s Janzen.

A spokesperson for the Pharmaceutical Research and Manufacturers of America, the industry trade group, acknowledges that companies are reticent about talking about bioprospecting in part because they don’t want to be perceived as stealing the flora or the intellectual property of indigenous peoples. Also, more of their efforts these days are going into high-tech drug discovery--using genomics to design drugs from scratch--rather than combing nature for medicines.

By contrast, bioprospecting is a hit or miss proposition fraught with obstacles, as biologist Steven King, chief operating officer of Shaman Pharmaceuticals in South San Francisco, can attest.

Shaman Pharmaceuticals started up in 1989, armed with a “short list” of a dozen promising medical plants that grew in specific regions, such as the northwest Amazon basin in South America. One plant in particular, which contained a molecule that Shaman scientists dubbed SP303, showed promise as an anti-diarrheal agent, just as indigenous healers had said it would.

Encouraged by the U.S. Food and Drug Administration to do the research that could get this extract approved on the “fast track” as a prescription drug, the company launched human studies, including one on 400 patients at 25 U.S. medical centers. The results were encouraging, King says, but apparently not quite good enough. The FDA wanted another study, but Shaman didn’t have the $15 million to $20 million to do it.

Shaman is now reorganizing in the face of bankruptcy and has decided to market its once-promising prescription drug as a dietary supplement, for which prior FDA approval is not necessary. The product is now sold in health food stores, under the rather drab name NSF, for normal stool formula.

Despite such bumps in the road, there is still considerable optimism that bioprospecting will yield new pharmaceuticals because of the sheer numbers of plant species in the world, many of which are as genetically complex as humans.

“Plants contain enormous numbers of genes, and if you multiply the number of species times the genes, the number is huge,” says biochemist Malcolm Morville, chief executive of Phytera Inc., a biotech company in Worcester, Mass.

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Because plants can’t move, the only way they can adapt to threatening changes in their environment is by turning on or off certain genes. “That’s why plants are of interest,” he says, “because genetically and chemically, they’re some of the most sophisticated species on earth.” Sponges and some other marine organisms use the same defenses.

While combing through nature for disease-fighting chemicals is a tedious process, it is a path well worth pursuing, says Mark Plotkin, an ethnobotanist who now heads the Amazon Conservation Team, a Virginia-based group dedicated to protecting biological and cultural diversity.

“Western medicine is the most successful, sophisticated method of healing ever devised, but it doesn’t have all the answers,” he says. “Rain forest shamans claim they can cure--not just treat, but cure--some of the things we can’t. Doesn’t it make sense to go ask these guys what they have?”

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Judy Foreman writes a syndicated column on health issues. She is a fellow in medical ethics at Harvard Medical School. She can be reached at foremanj@bellatlantic.net. Her column will run occasionally in Health.