The bark of the Pacific yew tree contains the chemical taxol, which can slow the growth of some cancers. (Craig Chanowski/iStock photo)
Thanks to stunning achievements in chemistry and biology, we now have numerous health products derived from natural sources. There is too much hype and quackery in some sectors, but there are dozens of proven lifesaving products. In two parts, I will share a historical perspective, along with exciting advances that affect our lives.
Why this topic? Too many people are ignorant about diversification in the natural world. When they hear of another obscure species listed as endangered, the news falls on deaf ears. Even recent research showing 1 million species at risk of extinction fails to stir most people to action.
Every species that disappears is a serious loss for the remaining species on Earth, and a lost opportunity for improved human (and animal) health. While our ancestors harnessed natural products for food and medical treatments, their methods were based upon trial and error. The quickening pace of technology advances in life sciences allows unparalleled speed and precision in bringing new products to market.
Even primitive societies such as the Neanderthals knew about medicinal uses of plants, e.g., using aspen bark tea as a painkiller. Ancient Egyptians used a concoction from white willow leaves to treat headaches, fever and inflammation. In the mid-1800s, German scientist Karl Gerhardt confirmed that several plants yielded the chemical salicin, which our bodies convert to salicylic acid. Using an extract from meadowsweet, Gerhardt was able to synthesize salicylic acid. By 1897, the German company Bayer had developed a commercial process for what we now know as aspirin.
Scottish scientist Alexander Fleming discovered penicillin in 1928. Fleming noticed that staphylococci bacteria died when in contact with a naturally occurring mold later called Penicillium rubens. In 1930, Fleming’s student Cecil Paine used a crude penicillin to treat neonatal conjunctivitis. By 1940, a process was developed to yield pure penicillin, in time to save uncounted lives during World War II. Unfortunately, the overuse of penicillin and later antibiotics led to drug-resistant microbes (more on that in Part II).
In 1982, I joined a biotechnology startup that became Genencor International. The initial focus was on enzymes — special proteins produced by living cells to catalyze specific biochemical steps. Our first project targeted unique enzymes for cleaning difficult stains in cold water. (Remember Coldwater Tide in 2005?) That required a very specific protease that was stable through the detergent manufacturing process and effective in room-temperature water. We tackled additional challenges, such as finding a cellulase that could produce stone-washed denim without stones, amylases that could tolerate wide pH ranges in the production of high-fructose corn syrup, and a lipase for making hard cheeses without the need for extracts from calf stomachs.
While the commercial enzymes were tailor-made using precise methods of DNA modification, it was critical to find unique enzymes in nature as our starting point. No matter how good our scientists were, Mother Nature remains the best biochemist, capable of amazing diversity.
We sent technicians to some of the most unusual environments on Earth to sample soils and water with hopes of finding undiscovered extremophiles, microorganisms that have evolved to thrive in extreme environments of pollution, salinity, temperature or pH levels. Our teams visited toxic waste sites, Yellowstone thermal springs, the forests of Kilimanjaro, even South American bat caves to obtain highly alkaline droppings.
A key target for the biotechnology industry has long been to find enhanced therapies for cancer. An early breakthrough was possible thanks to a slow-growing, near-threatened tree called the Pacific yew. Native Americans used its wood for crafting bows and canoe paddles. While the Natives knew the seeds were poisonous, bark and foliage were used medicinally. In 1962, scientists tested the bark and discovered a chemical called taxol that displayed an ability to slow the growth of some cancers by interfering with cell division. In 1977, clinical studies began evaluating taxol as a treatment for ovarian cancer.
However, there were not enough Pacific yews to support a marketable cancer drug. Our company sought to develop a cost-effective cell culture method to make commercial quantities of taxol without killing trees. Concurrently, chemists were evaluating extracts of the common yew tree in hopes of creating a new synthetic route to taxol. The chemists succeeded, yielding paclitaxel as the most well-known naturally sourced cancer drug in the U.S., used in chemotherapy for several cancers.
In Part II, I will share several more examples of scientific breakthroughs to life-giving products from the natural world, including one that saved our daughter’s life.
Ed Robinson’s latest book, “Nature Notes from Maine Vol. II: Puffins, Black Bears, Raccoons & More,” is available from the Harpswell Heritage Land Trust. All profits support HHLT’s conservation and education efforts.