70% of New Drugs Come from Mother Nature

Aug 9, 2011 by HHNSTAFF

Around 70 percent of all new drugs introduced in the United States in the past 25 years have been derived from natural products, reports a study published in the March 23 issue of the Journal of Natural Products. The findings show that despite increasingly sophisticated techniques to design medications in the lab, Mother Nature is still the best drug designer.

Reuters, which reviewed the new paper, reported that "drug discovery hit a 24-year low in 2004, with just 25 unique compounds known as new chemical entities introduced that year." Lead author, David Newman of the U.S. National Cancer Institute's natural products branch, said the advent of new drug discovery techniques in recent years diverted pharmaceutical company resources away from natural sources of new drug compounds.

"Chemists started making libraries of hundreds of thousands to millions of compounds. But they were simple compounds," Reuters quoted Newman as saying via telephone. "Mother Nature doesn't make simple compounds. Mother Nature wants compounds that fit into particular places."

Co-author Dr. Gordon Cragg says that one of the best examples can be found in taxol, one of the strongest cancer drugs on the market.

"Taxol came from the bark of the Pacific Yew tree. The USDA in a random collection in 1962 did the first collections in Washington State," Cragg said in a 2004 statement. "After decades, this produced one of the best anticancer drugs available."

Overall, say the researchers, "half of all anti-cancer drugs introduced since the 1940s are either natural products or medicines derived directly from natural products."

Despite this success, Newman says that few American firms are examining natural products for drug sources.

"Wyeth and Merck are the only two U.S. manufacturers of that size that still use natural products as one of their sources to look for drugs," Reuters quoted Newman as saying.

NCI's Drug Discovery Program began in 1955, initially collecting plants in the United States, Mexico, Canada, and parts of Africa and Europe, before expanding in tropical regions in 1986.

Newman and Cragg note that while random sampling can uncover some drugs, working with native healers, who use medicinal plants on a regular basis, is especially effective. For example, a 1990s study in Samoa found that 86 percent of the plants used by local healers yielded biological activity in humans. Other insights can be gained by observing which plants avoid predation and what plants are eaten by non-herbivorous animals.

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