Witch's brew? What drugs contain leech and lizard parts

Double bubble toil and trouble. A dash of Gila monster spit, some ground up cow lungs or yellow scorpion. These aren't the ingredients in any medieval potion, instead these are some of the ingredients pharmaceutical companies are using to help regulate blood sugar, make pills easier to swallow and slow a racing heart.

From rooster combs to snake venom to horse pee, pharmaceutical companies have adopted, and continue to investigate, strange ingredients from nature to treat illnesses.

Animal Parts

Humans have used animals and animal parts to improve their health for thousands of years. Ancient Egyptians, for example, coined the use of leeches for bloodletting around 1000 BC. Traditional medicine, defined as those that primarily use plants, animals and minerals to treat disease, today constitutes up to 50% of all the medicine taken in China and 80% taken across Africa, according to the World Health Organization.

The practice has also seeped into modern drug development. What's more, specific animal parts have garnered widespread acceptance from the pharmaceutical industry.

Take gelatin, a protein that comes from the boiled skin, tissues, bones or hooves of pigs, cows and horses. Most pharma giants, including Pfizer, Novartis and Merck, use gelatin to create the hard and soft capsules that house a pill's active ingredients. Gelatin can be found in products ranging from AbbVie's HIV drug Norvir to Johnson & Johnson's Avodart, a treatment for benign prostatic hyperplasia.

Another ingredient drawn from pigs and cows is the blood thinning compound heparin. The chemical is harvested from swine intestines and bovine lungs, and works as a protease inhibitor when ingested. Major forces in heparin production include GlaxoSmithKline, Pfizer and Sanofi. The global market for the drug is slated to grow past $5 billion by 2020, according to a March report from Sandler Research.

There are also plenty of drugs with more niche animal part usage. One is Healon, a drug that prevents tissue damage during eye surgeries and that Abbott Medical Optics acquired from Pfizer in 2004 during a $450 million buyout of the pharma giant's ophthalmic business. The active ingredient in Healon is a salt derived from hyaluronic acid, a chemical found in high concentrations in rooster combs. Researchers have found that, in addition to eye treatments, the extracted acid can function as an alternative to Botox, as well as help combat osteoarthritis in the knees. Given hyaluronic acid's medicinal advantages, drug makers have selectively bred roosters to produce larger combs.

Powerful poisons

Animal parts may not be the most appetizing ingredients, but health benefits like high concentrations of rare proteins make it easier to understand why they're included in pharmaceutical products.

Less obvious is animal venom.

Contrary to its poisonous character, venom and its biological effects have inspired the development of treatments for many hard-to-cure diseases. Capoten, for instance, is an ACE inhibitor that alleviates symptoms of hypertension and heart failure. Its active ingredient is captopril, which mimics a protein found in the poison of Brazil's Jararaca pit viper. The company that would later become Bristol-Myers Squibb first developed the drug in the 1970s, and in 2002 sold the rights to Par Pharmaceuticals.

Snake venom is just the tip of the iceberg, though. Bayer's Refludan has the active ingredient lepirudin, a recombinant of a compound found in the salivary glands of European medicinal leeches that prevents blood from clotting. Bayer stopped offering the treatment in 2012, however, after drug's third-party manufacturer shut down production. The Medicines Co. and Canyon Pharmaceuticals also have products with chemical derivatives of that same leech compound.

Jazz Pharmaceuticals's Prialt is a pain reliever with an active ingredient based on the venom from the cone marine snail.

AstraZeneca's diabetes drugs Byetta and Bydureon incorporate a synthetic version of a chemical found in the saliva of the Gila monster, a poisonous lizard that grows up to two feet long and lives throughout the Southwestern U.S. and Northern Mexico.

Biotechs Kineta and Blaze Bioscience have clinical-stage drugs that leverage toxin-derived ingredients from sun sea anemones and yellow scorpions, respectively.

Other stuff

Horse urine. Well, mare urine to be more specific. But who in the world would need that? Turns out women going through menopause may find relief from hot flashes and other symptoms with Pfizer's Premarin, a drug made, in part, from pregnant mares' pee. The company's Premarin products brought in more than $1 billion in 2015, according to its most recent 10-K filing with the Securities and Exchange Commission. To keep the supply of essential ingredients flowing, Pfizer contracts farms to breed mares, a move that has caused backlash from animal rights advocates.

Scientists also recently discovered the potential health benefits of sloth fur. In a PLOS One article published in January 2014, researchers collected 84 species of fungi growing in the thick hair of nine Panamanian sloths. Included in that collection were two fungi capable of affecting malaria, three known to fight a strain of human breast cancer, and eight that attack the parasite responsible for the spread of Chagas disease.

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Filed Under: Drug Discovery Manufacturing
Top image credit: J.W. Webb