Valuable Venom

Snakes often get a bad rap.

Those slithering, coiling reptiles make half of us feel anxious and a small percentage of us even have the snake-related anxiety disorder ophidiophobia.

Fangs aside, let’s look at the bright side of the serpent and some other creatures of the creepy crawly variety.

We can thank snakes, and other creatures such as scorpions and snails, for some life-changing and lifesaving drugs.

Chip Wukitsch, Director, Pharmacy Operations for Lehigh Valley Health Network, says scientists have long studied nature’s role as they work on developing more and better treatment options for many diseases. “Interestingly, researchers have turned to studying venom, something we all associate as being extremely dangerous – and rightfully so – in helping control or treat cardiovascular disease, manage pain and fight cancer, as well as in blood thinner medication,” Wukitsch says.

According to nature.com, the antihypertensive drug captopril was the first drug based on a bioactive component from snake venom. It was approved in the U.S. by the Food and Drug Administration in 1981. Captopril, based on an ingredient in the venom of the Brazilian viper, is used to treat high blood pressure and heart failure.

It was the first class of drug that acted to limit the effect of angiotensin-converting enzyme (ACE), which has a narrowing effect on blood vessels, which increases blood pressure. The drug class is known as ACE inhibitors. Enalapril is another drug developed with the help of snake-venom components. Roughly 40 million people worldwide rely on this class of medications to help improve their cardiovascular health, Wukitsch says.

The blood thinner integrilin, used to help heart attack patients, was derived from a protein found in the venom of the pygmy rattlesnake. The drug tirofiban, which helps prevent blood clots, evolved from a substance in the venom of a saw-scaled viper.

Snake venom is not alone in helping medical science. Helpful treatments also are derived from the venom of creatures such as cone snails, lizards and leeches.

“We have the cone snail to thank for the discovery of ziconotide, the only calcium channel-blocking peptide used to treat chronic pain,” Wukitsch says. “By preventing pain signals from reaching the brain, people suffering from cancerous tumors and HIV/AIDS may find relief.”

Speaking of lizards, the fearsome-looking Gila monster, the only venomous lizard in the U.S., has a distant relationship to the currently popular diabetes and weight-loss drug semaglutide, which is marketed as Wegovy for weight loss and as Ozempic and Rybelsus for type 2 diabetes.

Research dating back several decades on a hormone in Gila monster venom ultimately resulted in the creation of a synthetic hormone called exenatide, approved in 2005 by the Food and Drug Administration for the treatment of type 2 diabetes. Other drugs that also target our body’s natural hunger-regulating ability have since been developed – enter Wegovy and friends.

An equally ominous-sounding creature, the deathstalker scorpion, is also contributing to medical science. The scorpion’s venom contains a small protein, called a peptide, which has an affinity for tumor tissue. Researchers at Blaze Bioscience have designed an investigational drug, composed of a modified form of the peptide that is chemically manufactured, plus a dye which glows fluorescent under a special light.

The researchers are studying tozuleristide to see if it will help surgeons be more exact when removing cancerous tissue by allowing them to see the edges of a tumor in real time. Tozuleristide is currently in clinical development focused on pediatric central nervous system tumors. 

“Results from the study of venom components now show promise in cancer treatment as well,” Wukitsch says. “Researchers are working to understand the role venom plays in cell death with the hope it can be used for targeted cancer treatment. The deathstalker scorpion is just one of many venomous creatures that scientists hope can provide a cure for many.”

Researchers in Australia are working to develop a drug from the venom of a K’gari funnel web spider that would stop damage to cells from a heart attack or stroke.

There are many components to venom, and some of those parts have properties that can treat disease and help healing.

An article in Nature Reviews Chemistry notes that while snake venoms can vary widely in composition, they have scores of components – sometimes well over 100. The authors note “the compositional diversity is a rich playground for medicinal chemists, providing a collection of highly specific and bioactive compounds that offer many paths towards developing new therapeutic drugs.”

According to the National Oceanic and Atmospheric Administration (NOAA) Ocean Exploration, most drugs derived from natural sources come from land-based organisms. But they say researchers are increasingly looking to the ocean for new sources for new drugs.

NOAA says “systematic searches for new drugs have shown that marine invertebrates produce more antibiotic, anti-cancer, and anti-inflammatory substances than any group” of organisms on land. Think invertebrates such as sponges and other creatures of the briny deep.