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Cone Snail Venom: Medical Uses and Potential Benefits

Updated on November 20, 2016
AliciaC profile image

Linda Crampton has an honours degree in biology. She is very interested in the production of medicines from chemicals in nature.

A textile cone snail (Conus textile)
A textile cone snail (Conus textile) | Source

What Are Cone Snails?

Cone snails are ocean predators with beautifully patterned shells. The snails produce a potent venom to paralyze their prey. The venom contains a complex mixture of neurotoxins, chemicals that block the conduction of nerve impulses. Exciting research is showing that at least some of the neurotoxins have medical benefits for humans.

Scientists have discovered that one chemical in cone snail venom can act as a pain reliever. Other chemicals in the venom are being used to help researchers learn about the functioning of the nervous system. These investigations may lead to the creation of new treatments for various diseases. Scientists suspect that venom chemicals may have even more benefits for us, including the prevention of epileptic seizures.

A Deadly Animal

There are more than 600 different species of cone snails, all belonging to the phylum Mollusca and the genus Conus. Most inhabit the warm water of tropical reefs. The snails have roughly cone-shaped shells, which gives them their name.

The Life of a Cone Snail

Cone snails use their venom to catch small fish, mollusks and worms. Like other snails, cone snails move quite slowly. The exception to this rule is their equipment for catching prey, which moves impressively fast.

The snails have a tubular and extendable mouthpart called a proboscis. This contains a modified tooth that extends out of the proboscis and stabs the prey like a hypodermic needle. The tooth is barbed and contains a hollow channel that conducts venom from a poison sac at the base of the tooth. The venom is injected into the prey, immobilizing it. The tooth is then withdrawn as the prey is swallowed whole by the proboscis.

Cone snails have an eye on the end of two eye stalks, but they detect their prey by means of their siphon. This is a large tube that draws in sea water. The snail absorbs oxygen from the water. It also detects the presence of dissolved chemicals in the water, including those released by the prey. Cone snails often hide in the sediments of the ocean bottom with just their siphon protruding.

Conus geographicus is sometimes called the cigarette snail because after being stung a person is said to have enough time to smoke a cigarette before they die.
Conus geographicus is sometimes called the cigarette snail because after being stung a person is said to have enough time to smoke a cigarette before they die. | Source

Venom

The smaller cone snails can give humans a painful sting but aren't dangerous. The bigger ones - which may be as long as nine inches - can be deadly for humans. They will attack to defend themselves as well as to catch their prey.

Cone snail venom contains a complex mixture of many different chemicals. There are thought to be at least fifty to a hundred biologically active compounds in the venom. There may be as many as two hundred compounds in some versions of the venom.

The venom contains conotoxins, also known as conopeptides, which are short chains of amino acids. Conotoxins quickly stop nerve impulses from passing between nerve cells or from passing from nerve cells to muscles. These actions cause paralysis in the snail's prey.

The Geography Cone Snail: Venom Functions and Uses

Medical Uses of the Venom

Research into the properties of cone snail venom is making some exciting discoveries. At least some conopeptides are able to relieve pain, which they sometimes do very effectively. One kind is already being used as an analgesic (pain reliever) in humans and others are being tested. There may be many other uses for the chemicals in medicine.

Conopeptides are proving helpful in a non-clinical context as well. Each type seems to work by a very specific mechanism in the nervous system. Researchers are learning more about how the nervous system works with the aid of conopeptides.

The venom of each species of cone snail contains its own unique mixture of chemicals, which increases the likelihood that some venom chemicals may be useful to humans.

Conus magus
Conus magus | Source

Ziconotide for Pain Relief

After studying a conopeptide in the venom of a cone snail known as Conus magus, researchers have made a synthetic version of the peptide. The artificial chemical, called ziconotide, has some useful properties. It has been approved as a medication in the United States by the FDA (Food and Drug Administration) and is in current use as an analgesic.

Ziconotide can be very effective at relieving pain, but its effects are variable. Some people say that the medication has been a wonderful help for them, some say that it produces only minor or partial pain relief and others say that its benefits aren't worth the side effects that they experience.

Ziconotideis is not addictive. In addition, it doesn't cause the development of tolerance in a patient. Tolerance is a state in which a medication that was once effective no longer works. The medication is sold under the brand name of Prialt.

Ziconotide is used after other analgesics have been tried and have failed to work. It is prescribed only for people who are suffering from intense and prolonged pain, such as the pain that may be experienced by people with certain types of cancer or for people experiencing neuropathic pain.

How Does Ziconotide Work?

Ziconotide works by inhibiting the transmission of nerve impulses at synapses. A synapse is the region where the end of one neuron or nerve cell comes very close to the start of another one.

Normally, when a excitatory nerve impulse reaches the end of a neuron, it stimulates the release of a chemical called a neurotransmitter. This chemical travels across the tiny gap between neurons, binds to a receptor on the second neuron and then stimulates a new nerve impulse. Ziconotide inhibits the release of the neurotransmitter.

Structure of a Synapse

Ziconotide inhibits the voltage-gated calcium channels that are involved in synaptic vesicle movement. The vesicles normally release neurotransmitter molecules into the synaptic cleft.
Ziconotide inhibits the voltage-gated calcium channels that are involved in synaptic vesicle movement. The vesicles normally release neurotransmitter molecules into the synaptic cleft. | Source

Potential Drawbacks and Side Effects of Ziconotide Use

Ziconotide does have some drawbacks. It must be injected into the cerebrospinal fluid in the spinal cord (an intrathecal injection) in order to work. This is generally done via an infusion pump and a catheter, which must be implanted. Although the implantation may sound unpleasant, it may be very worthwhile for someone who is experiencing chronic and life-altering pain that can't be relieved by other methods.

A major advantage of injecting the drug directly into the nervous system is that the minimum amount required to relieve pain can be used. This is important because ziconotide sometimes produces significant side effects. One possible side effect of the medication is a mood change, including depression. Other possible effects are confusion, memory impairment, and hallucinations. The incidence of problems increases as dose increases.

A patient taking ziconotide must be closely monitored. The patient and people close to them should note any problems that develop. Fortunately, ziconotide use can be stopped abruptly without the patient experiencing withdrawal symptoms, allowing the side effects to disappear. It would be wonderful if researchers could discover how to block the unwanted effects of the medication.

Assorted Shells

Click thumbnail to view full-size
Conus regius or the royal cone snailConus jaspideus or the jasper cone snailConus archon or the magistrate cone snail
Conus regius or the royal cone snail
Conus regius or the royal cone snail | Source
Conus jaspideus or the jasper cone snail
Conus jaspideus or the jasper cone snail | Source
Conus archon or the magistrate cone snail
Conus archon or the magistrate cone snail | Source

Other Potentially Helpful Chemicals in Cone Snail Venom

Conantokins are a family of conopeptides found in cone snail venom. The best known member of the family is conantokin-G from the geography (or geographic) cone snail. The chemicals are sometimes called "sleeper peptides" because when they are injected into the brain of young mice they trigger sleep.

Researchers who are studying conantokins have discovered that they can block seizures in mice. The peptides work by a mechanism that may be helpful for humans with epilepsy. Their ability to block specific chemical receptors in the nervous system may have benefits beyond the treatment of epilepsy.

As is the case with some other cone snail chemicals, researchers have produced synthetic molecules based on the natural ones in order to improve the properties of conantokins for medical use. The chemicals are still being explored by researchers and are not yet available as medications. They could be very helpful in the future, however.

A Weird Animal

Population Status of Cone Snails

Unfortunately, some cone snail populations are in trouble. The snails die due to coastal development, ocean pollution, destructive fishing methods and climate change. In addition, they are collected and killed for their beautiful shells, which are popular as decorations. Some shells are sold for thousands of dollars.

Researchers at the University of York in the UnIted Kingdom have completed a population assessment for all of the 632 known cone snail species. The International Union for the Conservation of Nature (IUCN) assigns organisms to a "Red List" category according to their population status with respect to extinction. As a result of the cone snail survey, 67 species have been placed in the endangered, vulnerable or near threatened categories in the Red List. The loss of the snails and their neurotoxins could be unfortunate for humans.

Scientists are using these neurotoxins, some powerful enough to kill people, as the basis for research into the development of life-saving drugs for medical conditions including intense chronic pain, epilepsy, asthma and multiple sclerosis.

— University of York

Important Animals

It's sad when any species is threatened with extinction, but in this case the situation could hurt humans, too. What is especially worrying is that there are almost no conservation efforts for cone snails. The studies of the complex venoms of cone snails are slowly yielding wonderful possibilies for new medications. It would be very sad to lose the chance of improving treatment for pain and perhaps of discovering new treatments for diseases.

References

Information about ziconotide from the FDA

University of York cone snail survey

© 2014 Linda Crampton

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    • billybuc profile image

      Bill Holland 3 years ago from Olympia, WA

      I learn the most interesting information from you. Well done once again my friend. I am now armed for my next game of trivia. :)

    • CMHypno profile image

      CMHypno 3 years ago from Other Side of the Sun

      Another interesting hub Alicia. Its fascinating how we are discovering medicinal purposes for many venoms. Also how things can be so beautiful and yet so deadly.

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thanks for the comment, Bill. I appreciate your visits so soon after I publish a hub very much!

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Hi, Cynthia. Yes, it is fascinating that dangerous venoms can also have medicinal uses. There is so much to learn from nature! Thanks for the comment.

    • b. Malin profile image

      b. Malin 3 years ago

      I've MISSED your Amazing Hubs Alicia. This one was Scary and of course so Educational...who knew that such a Beautiful looking Snail could be so deadly and yet helpful in our Medical Field. I Enjoyed looking at the Videos as well. Voted UP and Interesting as well as Useful.

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thank you very much, b. Malin! It's great to hear from you again. I appreciate your comment and votes.

    • Faith Reaper profile image

      Faith Reaper 3 years ago from southern USA

      I always look forward to what you will teach me with your fascinating hubs, and here is another one where I learned a lot. It is sad about possible distinction when it is so helpful to man! That first photo I thought was part of a snake buried because of the pattern on the snail. They are so very beautiful and I have never heard of them before. I believe I have seen them possibly. I sure hope there is a movement to prevent such distinction from happening. We have probably not even touched the surface of all the possibilities as far as health and what every little creature can provide.

      It is great to learn something new and we can always count on you.

      Up and more and sharing

      Blessings, Faith Reaper

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thank you very much for the kind comment, Faith. I agree with you - I think we probably have only touched the surface with respect to the health benefits that other creatures can provide. Thanks for the votes and the share. Blessings to you, too, Faith.

    • Eiddwen profile image

      Eiddwen 3 years ago from Wales

      How interesting Alicia and thanks for sharing.

      Eddy.

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thank you, Eddy. I appreciate your visit.

    • bdegiulio profile image

      Bill De Giulio 3 years ago from Massachusetts

      Hi Linda, how fascinating. I've seen their shells but never knew they were called the Cone Snails. I had no ideas they were venomous? Or than their venom had medical uses. Thanks for the education. Voted up, shared,etc...

    • Writer Fox profile image

      Writer Fox 3 years ago from the wadi near the little river

      This is amazing information. Too bad this venom isn't available on Amazon yet (just kidding). Some sharp entrepreneur will take up the call and produce these snails commercially. Enjoyed and voted up.

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Hi, Bill. Thank you very much for the comment, the vote and the share! It's interesting that a snail that is so attractive can be both dangerous and useful.

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Hi, Writer Fox. Yes, I'm sure we're going to hear a lot more about the medical uses of cone snails in the near future. Thanks for the comment. I appreciate the vote, too!

    • Jodah profile image

      John Hansen 3 years ago from Queensland Australia

      Wow Alicia, what an amazing hub. I learned so much about the cone shell. I hope they find a way of protecting them as the research into their toxin seems to be having wonderful medicinal results in regard to pain relief, the treatment of epilepsy etc. Voted up.

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thank you very much, Jodah. I hope that cone snails are protected, too. There is so much to learn about the composition of their venom and its possible uses!

    • Nell Rose profile image

      Nell Rose 3 years ago from England

      That was amazing! who would have thought that these little things could be so helpful to medical science? and that pain killer, now called Prialt! unbelievable! What a great hub Alicia, and fascinating too, thanks!

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thank you for the visit and the lovely comment, Nell. Cone snails are certainly amazing animals!

    • CarolynEmerick profile image

      Carolyn Emerick 3 years ago

      Nature is amazing. How ironic that venom would have medicinal uses! I especially loved the images of those gorgeous shells. Found myself singing "Under the Sea" as I read along :-) Upvoted and shared

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thank you very much for the vote and the share, Carolyn. Nature is definitely amazing! I love the appearance of the shells, too - they're beautiful.

    • DDE profile image

      Devika Primić 3 years ago from Dubrovnik, Croatia

      Cone Snail Venom - Medical Uses and Potential Benefits is a very interesting hub. An informative, useful and a definitely a learning lesson.

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thank you for the visit and the comment, DDE. The cone snail is an interesting animal to write about!

    • CraftytotheCore profile image

      CraftytotheCore 3 years ago

      This is fascinating. I never knew snails could sting at all. Well-researched. I love the photos.

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thanks for the comment, Crafty. I appreciate it!

    • aviannovice profile image

      Deb Hirt 3 years ago from Stillwater, OK

      Sounds like we'd best make some conservation efforts here, so that more research ca occur on the conopeptides and other beneficial aspects. Why not snail farms?

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      This sounds like an excellent idea, Deb! We certainly need to conserve cone snails in some way. Thanks for the comment.

    • WriterJanis profile image

      Janis 3 years ago from California

      I had no clue about this. Thanks for the education. The shells are so beautiful.

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thank you for the comment, WriterJanis. I agree - the shells are beautiful!

    • teaches12345 profile image

      Dianna Mendez 3 years ago

      I was a little taken by a huge snail I found on our garage door awhile back. I found out we are supposed to report them because they are a threat to the eco-structure here in Florida. I would not want to be stung by one! A wonderful article, as always!

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      I suspect that I know what type of snail you're talking about, Dianna, since I've written a hub about it! Not all snails are venomous, but the cone snail certainly is. I think that it's an interesting animal, though. Thank you very much for the comment.

    • MartieCoetser profile image

      Martie Coetser 3 years ago from South Africa

      The information in this hub is totally amazing and very interesting. As always I have learned a lot in your corner. Thank you, Alicia :)

    • AliciaC profile image
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      Linda Crampton 3 years ago from British Columbia, Canada

      Thank you, Martie. I appreciate your comment and your kind support very much!

    • Kristen Howe profile image

      Kristen Howe 12 months ago from Northeast Ohio

      Alicia, congrats on HOTD! This was another fascinating hub from you. I've learned a bunch on cone snails and its venom. I've never even heard of them either. Thanks for sharing.

    • AliciaC profile image
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      Linda Crampton 12 months ago from British Columbia, Canada

      Thanks for the comment and the congratulations, Kristen!

    • Mel Carriere profile image

      Mel Carriere 12 months ago from San Diego California

      Congratulations on your hub of the day, Linda, for January 18th, 2016. I never knew that these pretty little snails that wash up on the beach contained something so deadly but also potentially beneficial to mankind. Great hub!

    • AliciaC profile image
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      Linda Crampton 12 months ago from British Columbia, Canada

      Thank you, Mel. I appreciate your congratulations and comment very much.

    • FlourishAnyway profile image

      FlourishAnyway 12 months ago from USA

      Congratulations, Linda! Such a well done hub, as all of yours are.

    • AliciaC profile image
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      Linda Crampton 12 months ago from British Columbia, Canada

      Thank you for the congratulations and the kind comment, Flourish!

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