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On Earth Day, salute the plants that make medicines possible

Today, in honor of Earth Day, a short true-or-false quiz:

• Plant-based pills and potions are gentle supplements safe for anybody to take.

• High-tech drugs that combat major diseases like cancer are man-made brews with no relation to nature.

Hint: If you think both statements are true, time to think again. Fact is, if you've ever taken a medication to improve your health, you can thank Mother Earth. For thousands of years, healers and scientists have relied on nature's pharmacy, primarily tropical forests, to treat everything from headaches and swelling to heart disease, cancer and Parkinson's. And on the flip side, plant-based medications can be addictive and even lethal if not used correctly. The powerful painkiller morphine, which led to the highly addictive drug heroin, is one example. It is derived from the pods of opium poppy plants. Worldwide, more than 100 drugs in use today can be traced to plants.

The origins of aspirin

"Without plants, we'd be in trouble," says Dr. Juan Sanchez-Ramos, professor of neurology at USF Health in Tampa. Sanchez-Ramos, a former pharmacy student and history buff-turned-physician, has done extensive research on the history of medications, particularly those related to Parkinson's disease. He says the majority of medicines have their roots in plants. "Some of the first pharmaceutical agents ever used were derived from plants," he says.

One of the most widely used drugs today dates to 400 B.C. The Greek physician Hippocrates is said to have used the bark and leaves of the willow to make remedies for pain and fever.

Later, scientists would discover that it worked because the tree produced a substance they named salicin, which gave birth in the 1800s to the remedy salicylic acid, what we now know as aspirin. The familiar white or orange tablets you buy at the drugstore are no longer made from bark and leaves, because, like many originally plant-based drugs, aspirin is made synthetically today in a lab using chemical copies of the active ingredient.

Re-creating nature

David Craig, a pharmacist who works in the integrative medicine program at H. Lee Moffitt Cancer Center in Tampa, counsels patients every day who want to include integrative or complementary alternatives in their cancer care.

"They take herbal remedies at home and want a more natural compound to fight their cancer," he says. "They often don't realize that many chemotherapies are plant derived. Because they aren't given flowers or leaves, it's often a surprise."

One of the best examples of plant-derived chemotherapy is the drug Taxol, which comes from the Pacific yew tree. U.S. government researchers working in the 1960s and '70s discovered its cancer-fighting properties and it soon emerged as one of the most promising new drugs for battling breast and ovarian cancers.

But it took hundreds of thousands of pounds of yew bark each year to produce enough drug for research to continue. Then a Florida State University chemist discovered a similar compound in the needles of the yew, a much more sustainable source than the bark, which could be converted to Taxol in the lab.

Taxol received FDA approval in 1992. The manufacturing process has been revamped; today, yew cells are synthesized in the lab using a process called plant-cell fermentation, according to Bristol-Myers Squibb, the maker of Taxol. The change preserves the trees, which are a favored habitat of the endangered spotted owl. Taxol is still one of the most important drugs used today to treat breast, ovarian and lung cancers.

Craig cautions patients who think that just because a drug or supplement is natural or plant derived it is risk free.

"People think natural substances are safer, that they have to be better for me than pharmaceutical products, but that's not entirely true," Craig says.

That's why it's always important to tell your doctor about any supplements you're taking, to avoid negative interactions with drugs you may be prescribed. For example, vitamin E should not be taken with blood-thinning medications such as Coumadin because it could increase the risk of bleeding. Ginseng can have the same effect when taken with aspirin or ibuprofen. St. John's wort can reduce the effectiveness of certain cholesterol-lowering and erectile dysfunction drugs. And ginkgo biloba can interfere with antiseizure drugs.

Saving the source

Many scientists and activists have rallied around efforts to protect the world's rain forests, believed to be home to more than 50 percent of the 250,000 plant species on Earth. There are many reasons to support conservation, but medical science fears that if we lose forests, we could lose an important source for new discoveries. Sanchez-Ramos also worries that regions like the Amazon are shrinking because of development and deforestation.

"That was our first source of medication," he says. "There may be so many things we will lose if we don't preserve it."

This week supporters of the Global Conservation Act of 2010 are in Washington to ask Congress to protect what they see as nature's drug development pipeline.

Among them is 48-year-old Debbie Trujillo of Tampa, a real estate agent and breast cancer survivor who was treated with Taxol and today has been cancer-free for five years.

"This is urgent," she says. "It takes years to find these plants, test them and get the drugs to patients. If there's a rain forest on the other side of the world that could save a life, we have to preserve it now."

Irene Maher can be reached at imaher@sptimes.com or (813) 226-3416.

White willow tree

Source of: aspirin (salicin), which treats pain, fever and inflammation.

Cinchona tree

Source of: quinine, which treats malaria.

Calabar bean

Source of: neostigmine,

which treats glaucoma and myasthenia gravis.

Horse chestnut

Source of: aescin, which treats circulatory disorders; may also be a blood thinner.

Coca plant

Source of: novocaine (derived from cocaine). Novocaine is a local anesthetic.

Rosy periwinkle

Source of: vincristine and

vinblastine, which treat several types of cancer.

Opium poppies

Source of: codeine, a cough suppressant and pain reliever; and morphine, a more powerful pain reliever.

Purple foxglove

Source of: digitalin, which treats heart failure; helps control abnormal heart rhythm.

Pacific yew tree

Source of: Taxol, used to treat breast, ovarian and lung

cancers.

On Earth Day, salute the plants that make medicines possible 04/21/10 [Last modified: Wednesday, April 21, 2010 5:48pm]

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