The deathstalker scorpion, Leiurus quinquestriatus, yields a compound that helps surgeons remove malignant brain tumors. (iStock photo)
As noted in Part I, an animal-derived product helped save our daughter’s life. The valiant doctors and nurses in the neonatal section of the hospital were the heroes of this story, but an extract from calves’ lungs played a key role.
Born in 1987 at 25 weeks gestation, before her lungs had fully developed, our daughter was placed in an incubator to give her the life-giving oxygen she needed to survive. Unfortunately, premature babies have fragile lungs and often suffer from a condition called respiratory distress syndrome.
Researchers had recently discovered that a compound called surfactant, extracted from the lung tissue of a calf, could be efficacious in the treatment of respiratory distress syndrome. As with all animal-derived products, the trick was in isolating surfactant that could be purified and would not trigger serious immune responses when administered to an infant.
We agreed to place our daughter in a clinical trial studying surfactant and she was given the product. Over many weeks in intensive care, she grew stronger and surmounted numerous challenges common to such low-weight babies. Ongoing studies have determined that surfactant extracted from pigs is superior to bovine material, and now scientists also have access to synthetic material to save babies born even earlier than our daughter.
Diabetes has long been a major cause of human suffering, as natural pancreatic cells cease producing insulin. Following World War I, scientists developed a process to isolate insulin from pigs, earning a Nobel Prize. In 1922, a boy with Type 1 diabetes received an insulin injection with beneficial results, other than pain and swelling at the injection site caused by impurities in the crude product.
For 60 years, animal-extracted insulin was the only choice for physicians to treat patients. By the 1980s, more pioneering science was able to produce human insulin with animal cells modified by the insertion of human DNA. Animal-extracted insulin is still available for patients in case they respond better to that product. Scientists have reported that clinical trial patients receiving modified human stem cells are now able to produce insulin, potentially freeing them from injections and medications that are common for millions of people.
There are thousands of viral diseases and medical conditions with limited or no treatments available to doctors. Traditional Chinese medicine and Indian ayurvedic medicine long used animal ingredients to treat conditions like arthritis, asthma or cancer, sourcing materials from animals such as tigers, seahorses, snakes and spiders. Most such therapies are not supported by scientific proof of efficacy, and the trade in those animals has pushed some species to extinction. Fortunately, thanks to genetic engineering science, it is no longer necessary to harm animals since you can carefully extract samples of their DNA.
Researchers are actively sourcing and studying materials from a wide array of animals so they can produce small samples of specialized chemicals for investigation. One focus area is a class of natural compounds called peptides, highly specialized mini-proteins that may have very specific modes of action in the human body. The best source for millions of complex and unique peptides turns out to be various forms of venom. With more than 220,000 species known to produce venoms, this is an area of particular focus.
For example, there is a compelling need to prevent permanent brain damage from strokes, with studies underway on a promising material isolated from the Australian funnel-web spider. The deathstalker scorpion yielded a compound that allows brain surgeons to see clumps of just 200 cancer cells during tumor removal surgery. A Brazilian tarantula carries a compound that kills human skin cancer cells in lab tests, a possible route to tackle melanoma.
Animal-derived pharmaceuticals are already available for numerous conditions. These examples were listed by the Animal Biotechnology Products Resource Center: eptifibatide, modeled on venom of the southern pygmy rattlesnake, to prevent heart attacks; ziconitide, from cone snail venom, for chronic pain; and batroxobin, from the venom of South American pit vipers, for blood treatments. Artificial intelligence now allows scientists to quickly screen millions of compounds, saving money and accelerating the long timelines for bringing new drugs to market.
We have a serious need for new antibiotics to treat deadly antibiotic-resistant bacteria, including those causing tuberculosis and MRSA. Demonstrating the importance of protecting even the smallest of creatures, a eumenine wasp provided peptides that show promising activity against such gram-negative bacteria. How many more potentially lifesaving compounds might exist in the natural world?
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.