The southern copperhead – Agkistrodon contortrix contortrix. It’s one of the most recognizable venomous snakes in the United States, second only to the rattlesnake. A common snake with a range from New England to Texas, everyone in the South knows what it is and what it looks like. And unfortunately, because it is venomous, it has a bad reputation and is sadly the victim of unnecessary fear-based killings.
A juvenile Southern Copperhead. The yellow tail indicates a young snake; as an adult, the tail will become copper-colored like the rest of the snake.
But what if I told you that the Southern Copperhead could save your life, or a loved one’s life one day? Would that help alleviate the fear of this snake?
It’s true – the Southern Copperhead’s venom is being studied as a possible breast cancer treatment, and the protein being used as a potential treatment is found only in the Southern Copperhead.
To understand how copperhead venom could help treat breast cancer, first, we must discuss how copperhead venom works.
How Does Copperhead Venom Work?
There are many different types of snake venom, and they all have different methods of action. This article will only discuss the venom of the Southern Copperhead.
Copperheads are pit vipers, and most pit viper venom contains hemotoxins. The phrase “hemo” comes from the Latin root “haemo”, meaning “blood”. Hemotoxins are proteins that negatively affect the functioning of the blood.
Viper venom contains many other toxic components as well, but the hemotoxins are the component that is important to their role in medicine.
In animal cells, the cell membrane contains many receptors on its surface so that it can communicate with or bind with material that is outside of the cell. One of these receptors is called an integrin. Integrins are very important for cell adhesion (which means they make cells stick together and stay together) and blood clotting.
One of the many functions of integrins is to tell platelets, which are cell fragments in the blood, to begin clumping together and to interact with proteins in the blood (coagulation factors) and form a blood clot. This is how your body is able to stop bleeding all by itself. When platelets form a blood clot, it is called “coagulation”.
Disintegrins are proteins in viper venom, and they do exactly as their name suggests – they stop the function of integrins. When you are bitten by a viper, such as a copperhead, the disintegrins in the venom stop your integrins from functioning.
This means that they prevent platelets from clumping and that they prevent the body from being able to properly form blood clots and stop bleeding. Because disintegrins stop blood from being able to clot, they are called “anti-coagulants”.
In addition to stopping the formation of blood clots, hemotoxins can also destroy red blood cells and cause serious organ and tissue damage.
Some species of rattlesnakes also have venom that contains hemotoxins.
How Do Copperheads Save Lives and Prevent Breast Cancer?
One of the common animal cell integrins that scientists are focusing on in cancer studies is called αvβ3 (alpha-v-beta-three). αvβ3 binds to a protein called “vitronectin”. Vitronectin causes cells to adhere together, and it is important in angiogenesis, which is the formation of blood vessels.
Cancer relies on both of these functions to spread – it needs to create more cancerous cells that are stuck together (cell adhesion), and it needs blood vessels to feed them. Platelets are needed to stabilize vessels while they spread and grow in new tumors. The spread of cancer is called metastasis. Metastasis is the cause of the majority of cancer patient deaths. Therefore αvβ3 is integral to the spread of, and death caused by cancer.
Southern Copperhead venom contains a protein called contortrostatin, which is a type of disintegrin. Remember from the first section that a disintegrin stops integrins from working. In a study done by the biochemistry and molecular biology lab of Francis S. Markland at the University of Southern California Keck School of Medicine, mice were injected with human breast cancer and then treated with contortrostatin. After multiple studies were done in this way, Markland found that contortrostatin reduced tumor growth by 74%, and inhibited metastasis by up to 68%.
Contortrostatin was found to inhibit the function of αvβ3 so that it could no longer bind to vitronectin. Since vitronectin can no longer bind to αvβ3, the cancer cells can no longer adhere to one another, the platelets cannot stabilize the formation of the blood vessels, and the blood vessels can no longer form. All of these results mean that cancer can no longer grow or spread.
Another study done by Markland studied the effects of contortrostatin on malignant gliomas. Malignant gliomas are a form of spreading brain cancer, and they are incurable. Contortrostatin was found to be effective in prolonging the life of mice with gliomas.
Finally, one more important advantage of contortrostatin is that the animal models seemed to have very few side effects.
You can read the original full study for free here. Two additional studies done on contorstrostatin can be found here and here, but these full studies are not available for free to the public.
This copperhead may save your life one day!
Why Shouldn’t I Kill Copperheads to Avoid Being Bitten?
While the description of the way copperhead venom works may sound scary, it is important to remember that copperhead venom is actually not very potent – copperhead venom is much less dangerous than other snakes’ venom. The bite may be painful, but copperhead bites are almost never fatal to humans as long as you seek medical attention. If any animal bites you, always see a doctor!
In addition to the low venom potency, no venomous snakes in the United States are aggressive. Snakes are very shy, and they would rather hide than bite a human in defense because the venom is very expensive to make and they don’t want to waste it on things that aren’t edible. If a snake wastes its venom on a human, it won’t have much venom left to catch food.
It can take days or weeks for snakes to replenish their venom if they use it all. Because of this, snakes do NOT want to bite humans, and they aren’t aggressive, nor do they chase people. 75-80% of all copperhead bites happen when people attempt to kill copperheads.
So, if you see a snake, walk away. Never attempt to touch it, harass it, capture it, or kill it. You are much, much less likely to be bitten if you walk away rather than if you attempt to kill a snake.
Copperheads live in the eastern half of the United States. They can be identified by their copper/beige coloration, and their “Hershey kiss” pattern.
Notice the “Hershey kiss” pattern on this copperhead.
It may not seem like a big deal to kill one snake. But if enough people kill enough individual Copperheads, they could become threatened or endangered. Every needlessly killed animal is a serious loss for the entire species’ population. Southern Copperheads are the ONLY species of snake that we know of that produce contortrostatin. If they were to become endangered or extinct due to needless killing of their species, we could lose a potential cancer treatment, and thousands of human lives could suffer.
If you would like to learn more about snakes, how to ID them, why you shouldn’t kill them, and what to do if you find one, please visit my other article, “How to Tell if A Snake is Dangerous”.
Snakes save lives. Snakes protect us from disease and famine, and they may even help us cure cancer! I hope that this article helped to convince you that the only good snake is a live snake!
IMPORTANT: The content in this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
