Traditionally, Tibetan doctors spend a month each year collecting small quantities of medicinal plants for traditional healing. Now, however, commercial collectors scour the steep, rocky slopes in search of snow lotus blossoms, which they harvest just before the flowers go to seed, says Jan Salick, Senior Curator of Ethnobotany at the Missouri Botanical Garden and a renowned expert in the field. Because the lotus hunters prefer the largest blossoms, only the smaller plants remain to propagate. As a result, the plant has actually evolved four inches shorter over the past century – a conclusion she and her graduate student, Wayne Law, drew by comparing lotus flowers found in the market with those in museums and protected areas on a sacred Tibetan mountain.
But to Salick’s way of thinking, environmental change could pose an even greater threat to the snow lotus. Global warming has shrunk Tibet’s 46,000 glaciers that feed many of Asia’s biggest rivers and provide water for more than a billion people. As the glaciers retreat, trees and shrubs that formerly lived at lower elevations are moving up the mountains. “The plants that grow at the higher elevations are being pushed off of mountain tops by the faster-growing weeds, trees, and shrubs,” Salick says.
“It’s a double whammy: the snow lotus cannot sustain the high level of harvest under commercial collection, along with the climate change,” she says.
Other Species Threatened
The snow lotus is not alone, the experts say. All across South America, Africa, Southeast Asia, and other regions, overharvesting and environmental change are threatening plants that have healed humankind for millennia.
Every year, about a half million tons of dried medicinal plants are traded internationally, according to the World Wildlife Fund, the largest multinational conservation organization in the world. Furthermore, more than 50 percent of the plants are collected from the wild. Combined with land conversion, habitat degradation, and increasing commercial demand, about 15,000 of the estimated 50,000-70,000 plant species used for medicine, cosmetics, or dietary supplements are threatened, the organization reported on its Web site.
Botanic Gardens Conservation International (BGCI), headquartered in Surrey, England, has reached similar conclusions. Plants play a vital part role in the world’s biological diversity and have become an essential economic resource for humans, says Belinda Hawkins, the author of the organization’s study, “Plants for Life: Medicinal Plant Conservation and Botanic Gardens”. “Yet plant and animal extinctions are occurring at a rate unmatched in geological history, leaving ecosystems incomplete and impoverished. In short, we are asking more and more from natural ecosystems even as we reduce their capacity to meet our needs,” she says.
Plants Play a Vital Role
Indeed, plants have played a vital role in healing. The World Health Organization (WHO) estimates that 80 percent of the primary healthcare in Africa, South America, Indonesia, Tibet, and other developing countries depends principally on medicine men and shaman who practice herbal-based medicine.
Although indigenous cultures in the developing countries are the primary users of these plants – and are particularly vulnerable to climate change, changing land uses, and over harvesting – western cultures also have benefited from medicines derived from Mother Nature.
A study of the top 150 drugs used in the U.S. found that about 57 percent of all prescriptions contained at least one major active compound that was either derived from or patterned after compounds from biological diversity, according to Plantlife International, a non-profit organization in the United Kingdom. Examples abound: morphine and codeine cultivated from opium poppy, quinine from the cinchona tree, and Digitalin medicines from the leaves of the foxglove plant.
Perhaps the most important discovery made in recent times involves the use of the slow-growing, environmentally protected Pacific yew to extract an active compound – commonly known as Taxol – that treats breast, ovarian, lung, bladder, prostate, melanoma, esophageal, as well as other types of solid-tumor cancers. Although scientists discovered a way to synthesize the compound in the laboratory, the method proved too complicated and costly. They then found a way to produce Taxol from the needles of several other yew species, creating a market for hedge clippings in the United Kingdom and France. To this day, plants remain the only source of this wonder drug.
Over the years, plants also have served as the inspiration for many other commonly used drugs. Today, companies produce aspirin inorganically, but the universally used treatment for fever actually traces its heritage to folk uses of willow bark.
Other Cures?
Today, the search continues for other potential life-saving drugs derived from plants, says Steve Richter, microbiologist and president of Microtest Labs, a Massachusetts-based company that provides testing and contract manufacturing services for the medical device, pharmaceutical, and biotechnology industries.
Not only do pharmaceutical companies dispatch representatives to the remotest corners of the globe to talk with local shaman about medicinal plants and their uses, they also spend millions of dollars on time-consuming laboratory testing to better understand the active ingredients. For U.S. companies, their investments are worth the effort – especially if they learn how to synthetically reproduce the active ingredient, which then would allow them to patent the process and eventually apply for Food and Drug Administration approval of a new, potentially lucrative drug.
Repercussions for Humankind
The question that Richter and other experts ask is what will happen if environmental change persists unchecked? “We’re certainly going to see some outcome,” Richter says. “I’m not a prophet about what can happen, but one of those possible outcomes is that we’re affecting our ability to mine new cures from these beautiful plants.”
Hawkins agrees. “We are losing plant species whose medicinal properties we are unaware of, as well as those whose healing qualities are well-known and hugely important,” she says. “We are losing what keeps us well. Though a complex issue, isn’t this foolish and tragic? What if we had lost Catharanthus roseus? This tiny flower from environmentally ravaged Madagascar has increased the chances of surviving childhood leukemia from 10 to 95 percent.”
Conservation a Must
She believes conservation is the first order of business. Medicinal plant conservation depends on the absolute protection of intact, undisturbed habitat, the widespread adoption of sustainable harvest methods, fair and equitable cultivation programs where appropriate, and stringent regulation of the trade in threatened species, she says. To make this happen, many stakeholders, including the pharmaceutical industry, policy makers, consumers, farmers, and middlemen, all must cooperate, she adds.
“Quite simply, if we don’t manage to curb our excessive consumption of all things, and soon, the planet will eventually be unable to support human life,” she says.