Achieving firsthand experience with snake venom is probably not high on anyone’s list of things to accomplish in life. Even the most harmless snakes aren’t exactly cuddly or loveable, so it’s no wonder that people aren’t rushing to extol the virtues of the many species whose bite can kill a human within a matter of hours.
Like sharks and spiders, snakes occupy a special place in the animal kingdom that humans often consider “fascinating but terrifying.” As much as we’re scared of them, we know that their venom has healing powers that many of us don’t fully understand. And just like spiders and sharks, snakes occupy a very special place in the environment and the food chain. For humans, they hold a special promise, because their venom, the very thing that makes them so fearsome, might hold the key to curing some of our worst diseases.
Picking the Right Poison
Snake venom is an astoundingly precise and effective product of evolution. Of the approximately 3,000 species of snakes in the world, only about 650 are venomous, and most of the deadliest kinds live in Australia, Asia, Africa, and Central and South America. There are roughly twenty-four known kinds of snake toxins, which vary between species and even subtly between members of the same species. Venoms mainly work in one of two ways, either by interfering with the circulatory system or by disrupting the nervous system.
No matter what part of the body the venom targets, all snake venom is incredibly effective. In the 1960s, doctors began looking at its effects on prey and realizing that venoms affected the same systems as many human diseases, but had the opposite effects. Researchers began wondering if they could find a way to use the venom itself, in smaller, more controlled doses, to cure those diseases.
The hunch was right and venom has proven extremely helpful in the treatment of heart disease, especially congestive heart failure and high blood pressure. Until the past few decades, there was no reliable treatment for high blood pressure until a Brazilian researcher began investigating the venom of the Brazilian pit viper (in the same family as rattlesnakes), when he realized that people bitten by the snake experienced a sudden and severe drop in blood pressure. Scientists discovered that the venom contains a protein that blocks the enzyme in the body responsible for regulating blood pressure. In a snake’s lethal dose, it causes the circulatory system to shut down, but when doctors created a less potent synthetic form, the result was the first ACE inhibitor, the most common class of drugs to treat the chronic condition.
