Thanking Nature, For Medicine

If someone saves your life, you want to express your gratitude however you can - a gesture, a "thank you" or somehow returning the favor. Yet when you owe your life to a plant found thousands of miles away, the task becomes much harder.

As a nurse, I've known for years that many life-saving medicines come from plants and animals found around the world. But I never thought that one day I would have to rely on the bark of a rare Asian tree to survive.

Nine years ago, I was diagnosed with appendiceal cancer and told that I had only months to live. The mother of two young children at the time, I could not accept the prognosis. Luckily, I found a doctor who was willing to help me fight. I had major abdominal surgery and months of chemotherapy.

Today I am cancer free, in large part because of irinotecan. A drug that helps block the growth of cancer cells, irinotecan is derived from a tree with banana-shaped pods found only in China and Tibet and aptly called the "Chinese Happy Tree." Yet, this tree and many other potential sources of future treatments are endangered and could soon be gone forever.

I have lived many years past my life expectancy. And countless others are alive and healthy today because of other medicines - from those that help lower cholesterol to those used to fight malaria - originally derived from natural sources.

Across the globe, however, many of our remaining wild areas that shelter plants and animals that could be the future source of numerous other new drugs are quickly disappearing. The razing of a forest in what seems like a remote corner of the world could have life-or-death consequences for people here in the United States.

Plants can't move to escape harm, so they use a complex chemical arsenal to protect themselves from insects, diseases and other threats. And many of these compounds have the potential to protect not only plants, but us as well. Indeed, half of all of the new drugs developed in the last 25 years, and 70 percent of the drugs currently used to treat cancer, have been derived from nature.

To create the new HIV drug, prostratin, scientists extracted chemical compounds from a tropical plant found in Western Samoa. The drugs vinblastine and vincristine, which treat leukemia and lymphoma, are derived from the rosy periwinkle, native to Madagascar, and there are hundreds of other examples.

Medicines have also been obtained from many animal species, some on the verge of extinction. The diabetes drug exenatide (more commonly known by its brand name "Byetta"), for example, was synthesized from a compound found in the saliva of the gila monster, an endangered lizard native to Mexico. Heart transplant survivors often take isinopril, which was derived from the venom of the Brazilian pit viper.

In 40 years, however, the habitats of these plants and animals may be gone. We lose 32 million acres of forests each year - an area almost the size of Louisiana. Scientists estimate that two-thirds of all species could become severely endangered by the end of this century. Yet researchers have only had the opportunity to test 1 percent of rainforest plants for organic compounds that could benefit human health. If we don't act soon, natural sources that could cure cancer, arthritis, HIV, diabetes, heart disease and innumerable other illnesses, may be lost to us forever.

Most of the planet's species live in the world's poorest nations and that's why I travelled, along with other cancer survivors from around the nation, to Washington last month to support a new effort in Congress to strengthen our nation's international conservation efforts. Introduced earlier this spring, the Global Conservation Act would establish a national strategy that will help our government assist in preserving the natural areas of developing countries that are too poor to do so on their own.

I'm grateful for the Chinese Happy Tree, which helped save my life and allowed me to watch my two daughters grow up. Speaking out for nature and all the medical treatments that come from it is just my way of saying "thank you."