Sixty Medicinal Plants from the Peruvian Amazon: Ecology, Ethnomedicine, and Bioactivity, (Sesenta Plantas Medicinales de la Amazonia Peruana), Cristian Desmarchelier, Fernando Witting Schaus. 2000. 270 pp., color illustrations, softcover. ISBN 9972-9186-0-2. $25. ABC Catalog #B465

Late in 2000, I heard National Geographic’s Joel Swerdlow repeat at the National Zoo in Washington, D.C., what he had said in a Washington Post excerpt of his attractive new book,¹ also featured in HerbalGram.² "Since the early 1960s, the Food and Drug Administration has approved more than 5,000 prescription drugs, yet fewer than a dozen have been based on plants or chemical formulae found in plants." And, he added, none came from previously unknown species of the Amazon rainforest. That contrasts with what chemist A. Douglas Kinghorn says: "As many as 50% of the most widely prescribed drugs in the U.S. are either small-molecule natural products or synthetic molecules that were synthesized using natural products as templates in their design."3 So Swerdlow’s estimate is pretty close to 0.02% natural or copycat (synthetic patterned after the natural), while Kinghorn estimates up to 50% natural or copycat.

These disparities seem to accrue to what politicians now call "parsing" or "spinning." Different researchers come up with different statistics. By careful choice of words, we could defend Kinghorn’s or Swerdlow’s very different figures.

When I asked Swerdlow about his comment that no new FDA-approved drugs had recently been developed from the Amazon rainforest, he qualified that his researchers said something like "no pharmaceutical drug has come out of the Amazon rainforest beyond those based on plants encountered by the conquistadors and their successors more than 300 years ago."

However, I have other firsthand sources. Back in 1991, despite my having a slipped disk, I boldly went to Iquitos, Peru on my first ecotour, which presaged the ABC Pharmacy Ecotours to the Amazon. I dedicated my week there to the Amazonian papaya (Carica papaya L., Caricaceae), source of the proteolytic enzyme, chymopapain. Chymopapain had only recently been approved for treating the slipped disk and I had a very personal, pragmatic interest. This surely constitutes one Amazonian medicine, derived from a strictly Latin American species, recently approved by the FDA. But, then, Swerdlow’s researchers may well be right after all. Clearly the conquistadors knew papaya as a fruit, even if not as a source of a drug for slipped disk.

In reviewing the importance of this compact new bilingual illustrated book on Amazonian plants, I’d like to list four different billion-dollar drug plants (all of which are growing in my garden): mayapple (Podophyllum peltatum L., Berberidaceae), source of the etoposide used to treat testicular cancer; madagascar periwinkle (Catharanthus roseus (L.) G. Don, Apocynaceae), source of vincristine and vinblastine to treat leukemia and lymphoma; wild yam (Dioscorea villosa L., Dioscoreaceae), the original starter material for the steroid industry, which gave us contraceptives and hormones; and finally, the Pacific yew (Taxus brevifolia Nutt., Taxaceae), source of taxol, used to treat uterine cancer, first approved as a drug in 1992, and selling for over a billion dollars last year alone. If we can find four billion-dollar drug plants in my humble and domesticated backyard, how many are lost as we cut and burn that irreplaceable Amazonian forest?

True, more of our plant drugs are sourced in the Temperate Zone, which has fewer, if better studied, species. But most of our phytochemical drugs could be sourced in the tropics. For its area, the Amazon has the world’s greatest species diversity Perhaps the Amazon contains a quarter (i.e., 75,000 of 300,000) of the world’s higher plant species, yet is the least studied area in the world. With more species in the tropics, and assuming each tropical species is as well endowed with unique phytochemicals as each temperate species, it’s simply an order of magnitude: more phytomedicines await discovery in the tropics.

This potential is one of the reasons why the American Botanical Council sponsors its annual Pharmacy in the Rainforest tours to Amazonian Peru. We have introduced hundreds of North Americans—many of them healthcare professionals—to the stunning diversity of the rainforest near Iquitos, Peru. Our trilingual guides there point out many of the important medicinal plants to these visitors, while Mark Blumenthal discusses the markets for them and their regulation in the U.S. and elsewhere in the world, and I discuss, where feasible, the scientific rationale behind their use. This new Sixty Medicinal Plants is now on the recommended reading list for our Amazonian ecotourists.

Of the three main books pertinent to the area, this new one is outstanding. It is bilingual; the other two are only in English. The bilingual feature of Sixty Medicinal Plants is its greatest asset, enabling Peruvian guides to learn their botanical English, and the gringos to learn some Spanish at the same time. The illustrations vary in quality (and make one mistake), but along with local names, will help the traveler elsewhere in Amazonian Peru.

Following a two-page introduction, the 60 species (some, like Cinchona and Juglans, are not really Amazonian) are covered in some 210 pages, an average of three and a half pages per species. In both languages the authors give the Common Name, Family, a terse Description, notes on Ecology, more extensive notes on Ethnomedicine, and then a section on Bioactivity, and source lists of References. To sample an entry, cat’s claw (Uncaria tomentosa (Willd.) DC., Rubiaceae) fills two pages with text, though the uña de gato, as it is called in Spanish, is the most likely of the 60 herbs to be encountered in a North American herb store. In the Bioactivity section on cat’s claw, we read that extracts show anti-inflammatory, antiviral, contraceptive, and cytostatic activities and the mix of six oxyindole alkaloid increases phagocytosis. Extracts can also inhibit synthesis of DNA in sarcoma 180. Antimutagenic properties have been demonstrated in vitro. The proacyanidins in the bark have well known antioxidant properties. "Aqueous extracts shows no signs of toxicity," according to the compilers. A third page shows the molecular structure of two of its constituents, a fourth contains eight references pertaining to cat’s claw, and a fifth has a color photo.

On my last trip to the Amazon, I gave copies to the botanically inclined guides, and left one at the one-room schoolhouse in the Ma’Huna village in Sucasari. Peruvians are hungry for bilingual publications, with pictures, and folk uses, and common names. Come join us in Peru sometime soon. You’ll love it. And bring this book, it will help you remember 60 of the thousands of interesting plants you’ll encounter. The numbers of species are overwhelming and, perchance, forgettable, but the experience is even more overwhelming, and unforgettable.

— James A. Duke, Ph.D.

References

1. Swerdlow JL. The promise of plants. Washington Post/Health. 2000 Sept 19:12-4, 17.

2. Swerdlow, JL. Nature’s medicine: Plants that heal. HerbalGram 2000;49:44-51.

3. Kinghorn, AD. 2000. Exploring nature’s pharmacy. Review of Medicine Quest: In Search of Nature’s Healing Secrets, by Mark Plotkin. C&E News, 2000 Sept 11:32-3.