Miraculous Venom of Marbled Cone Shell Snails - Essay Example

Miraculous Venom of Marbled cone shell snails Marbled cone shell snail or Conus Marmoreus (Courtesy of Australian Venom Research Institute) Abstract: The venom of concus marmoreus or marbled cone shell snail is lethal and a single drop of it can kill twenty people or more. However, this venom contains natural conotoxins, which upon inducement in terminally sick patients; blocks certain ion channel of the brain signals to relief them from the pain. Thus, these specifically produced neurotoxins of the cone shell snail venom are extracted to produce drugs which impede the neurological activity of the brain cells in transmitting the pain signals to the brain. Introduction: Unlike any living creature on Earth, humans and animal are born with an intrinsic sense of defence from any potential threat. Though, the defence mechanism can differ, but it still causes serious injury to the victim (prey) or survivor (attacker). Some animals use their claws, sharp teeth or horns and other strong body parts (tail or legs) to shield and defend from the potential danger; others, intimate their opponent with stings, bites or even with a single lethal touch. The term poisonous or venomous animal is generally used to refer the category of animals, which use their poisonous toxins or venom for attack or defence. However, there is a significant difference in the meaning of poison and venom. The former is absorbed by a touch and the later is injected through a bite, sting or stab. Thus, venom containing animals purposely inject their injurious toxins and poisonous animals contain poison in their skin, which is absorbed upon a single touch. The effect of the venom differs, as it is mainly dependent upon the amount of venom injected and the physical health of the victim. Therefore, venomous animal are active slayer and poisonous animal are passive slayer. Majority of the venoms are highly complex proteins that instantly or slowly deficit nervous system of humans or animals and adversely affect the blood circulation of the victim. Marbled cone snail or conus marmoreus is categorized as the most lethal animal in the world due to its potency of venom, but specific neurotoxins or conotoxins of its unique venom are utilized by the pharmacists to produce drugs, which have the potential to cure terminal pains. Marbled Cone Snails: Hierarchy: These beautiful tropical and sub tropical species have approximately 700 carnivorous predator kinds and almost eighteen of them cause human envenomation. Biologically known as Conus marmoreus, are generally termed as marbled cone snail, they nourish and breed on the reef of the oceans and are known as marine snails. These species belong to family of Conidae and fall into the phylum Mollusca. Their class is gastropoda and their order in the phylum is Sorbeoconcha (Mander et al., 2010). Nevertheless, they are mainly distributed according to their prey or feed. For instance, Vermivorous intake worms, Molluscivorous intake mollusc and Piscivorous feed on fish. Mollus and fish feeding cone shell snails contain more toxic agents in their stings comparatively to the worm eating cone snails. These invertebrate aquatic species are approximately six inches in length and weigh almost seven to eight grams. Moreover, they have calcareous shells, which withhold un-fragmented malleable bodies of these snails (Brent et al., 2005, p.1237). Characteristics: Conus Marmoreus are generally found on the reefs of Pacific Ocean, Bay of Bengal, India, Okinawa, Caribbean and Red sea, New Caledonia, Marshall Islands and Samoa. These species are well known for their lethal and unique venom, which has the ability to kill twenty people at a time with only a single drop. It typically attacks its prey with its long and white proboscis and it inserts the harpoon-like radualr teeth, which injects neurotoxin in its prey. The neurotoxins of the marbled cone snail affects the victim in several possible ways , thus it stimulates and causes paralysis, syncope, heart failure, loss of coordination of the central nervous system, permanent or temporary blindness, nausea, double vision and intricacy in inhale and exhale. However, till date, only 30 human deaths have been recorded due to venom of cone snails (Dobbs,2009). Venom injecting mechanism of marbled cone snails: The unique venom of marbled cone snail is inserted and transported through its long tubular duct, which is longer than the length of the snail itself. Cone shell snails can use this tubular duct for catching it prey from both end of its shell. This tubular duct is connected to muscular bulb, which upon contraction and expansion provides force to its radular teeth for venom injection. These radular teeth have a hollow spear like shape and they are filled with the toxic venom, which are then transferred to the buccal cavity so they can be delivered to the proboscis. Eventually, proboscis retains this venom to the radular muscle of the marbled cone snail. When the prey or threatening creature comes into a close proximity of these snails, proboscis instantly spike the harpoon into the flesh of the victim and injects the venom in their body. The harpoon then acts like a fishing rod and it rolls through its “’gastropod/thread”. Venom injected through the harpoon paralyzes the victim instantly and eventually gastropod chord rolls it up for the snail to eat. Outcomes of the venom: When cone snails target its prey the venom attacks the nervous system and it impedes the ion channels to prevent the coordination among different organs of the body. With the blockage of ion channel, the signals which transfer from neuron to neuron for a muscle cells to perform any function; stop instantly. Thus, the conotoxins in the venom impede the ion channels and nervous system stops working and eventually; appears the paralysis condition. Thus, paralyses can occur in the form of excitotoxic shock or as a placid paralysis. Properties of the venom: The fundamental property of the cone snail venom is its paralyses potential, whether enabling severe paralysis or mild. Thus, the tiny active peptides of poison contain concentrated amino acid residues with high disulfide bonds. The amino acid contains 12-30 residues and with each injection of the venom a different composition is inserted in the exposed muscle of the prey. The venom of the snail contains paralytic neurotoxic peptides, which impedes the neuronal coordination of the victim’s body and enables the marbled cone snail to engulf its victim (Olivera & Teichert, 2007). Cone shell snail sting cure: There is no anti-venom developed to cure the sting of conus marmoreus or to relief its adverse effects, although pressure immobilizing strategy is applied on the human victims, who happen to be stung by them. Moreover, mechanical ventilation also revitalizes the respiratory impedance faced by many patients. The abrasion of the conus marmoreus is considered as infected and tetanus prophylaxis is advised to be applied on such wounds. Venom Used for medical purposes: Upon recent research on the toxic and lethal venom of Cone shell snail or conus mamoreus, pharmacologist have found it significantly valuable in producing pain reducing drugs for chronic or terminal pains. The potent concoction of neuronal toxins produced by the snail due to lack of agility, enable it to paralyze its victim. Thus, Marbled cone snail venom produce consistent disulfide rich peptides (Conotoxin or conopeptides), which entail the strength to reduce the pain and influence the human nervous system (Walker & Wood, 2005). The compound of the cone shell venom is intricate and it contains almost fifty chemicals, which diversely influences human nervous system. Researchers also deem that 50,000 or more neurotoxins or conotoxins exist in the venom of a cone shell snail. Therefore, a drug produced from the venom of the cone shell snail entails the properties to reduce the pain of the patients with HIV, diabetes, cancer, multi sclerosis and many terminal and chronic diseases. The drug produced from snail venom is thousand times more effective than morphine, is non-addictive and relatively taken in smaller amount. These conotoxins cannot be orally taken as they quickly dissolve into the bloodstream and therefore, these conotoxins do not reach the intended receptor for the sake of cure. Therefore, they are injected in the spinal cord of the patients to be transported directly to the nerves. In 2004, one conotoxin was authentically approved by the FDA in USA and is still used to produce a drug known as (Ziconotide) Prialt. Hence, this drug has set an example to research on the potential of the other conotoxins in snail venom to produce cure drugs for terminal diseases. Prialt was initially produced by a pharmaceutical company known as Elen Corporation in Dublin, Ireland. The main purpose of this drug was and still is, is to influence the calcium channel of the patients to impede the activity of pain perceiving signals and to defuse the transmission of pain inducing signals (Prager, 2011). The toxin of marine cone shell snail is also deemed to cure an incurable brain disorder known as dystopia. Thus, this neurological disarray reduces the efficiency and repetition of muscle contraction, which eventually becomes a cause of abnormality in the sufferer. One percent of Americans suffer from this rare disorder and scientists are working towards to create a drug from a small protein in the venom of the cone snail known as XEP-018. However, the research on this drug is for therapeutic purpose and the drug produced through this experiment is under clinical trials for the time being. Thus, the pharmacologists are aiming to design it as an oral intake drug rather than an inject-able one (Giordani, 2012). Conclusively, marbled shell cone snails or conus marmoreus are non aggressive species who are toxic, but their toxicity is beneficial to human kind, if it is utilized to produce drugs for terminal ailments. Therefore, marine environment and reefs should be protected and made pollution free zones for their proper nourishment and protection of their natural habitats. Appendix 1: For Conus marmorious’s venom affect on the body of the victim: a-conotoxins Competitively block muscle and vertebrate neuronal nicotinic ACh receptors g-conotoxins Activate pacemaker cationic channel d-conotoxins Activate predominantly mollusc sodium channels k-conotoxins Block potassium channels m-conotoxins Block vertebrate muscle/nerve sodium channels s-conotoxins Inhibit 5HT3 channel y-conotoxins Non-competitively block muscle ACh receptors w-conotoxins Block N-type or P/Q-type vertebrate calcium channels conopressin Vasopressin agonist conantokin Inhibit vertebrate NMDA-glutamate channels (Courtesy of Australian Venom Research Unit, 2013) References: Australian Venom Research Unit. (2013). Cone snail. Retrieved from http://www.avru.org/health/health_cones.html Brent, J., Wallace, K. L., Burkhart, K. K., Phillips, S. D., & Donovan, J. W. (2005). Critical care toxicology: Diagnosis and management of the critically poisoned patient. Estados Unidos: Elsevier. Dobbs, M. R. (2009). Clinical neurotoxicology: Syndromes, substances, environments. Philadelphia, PA: Saunders/Elsevier. Giordani, A. (2012, 4 18). Computing and cone snail creates new painkiller. Retrieved from http://www.isgtw.org/feature/computing-and-cone-snail-creates-new-painkiller Mander, L., Liu, H.-W. B., Townsend, C. A., Ebizuka, Y., Moore, B. S., Crews, P., Verpoorte, R., ... Whitman, C. P. (2010). Comprehensive Natural Products II: Chemistry and Biology. Amsterdam: Elsevier Science Ltd. Olivera, B. M., & Teichert, R. W. (January 01, 2007). Diversity of the neurotoxic Conus peptides: a model for concerted pharmacological discovery. Molecular Interventions, 7, 5, 251-60. Prager, E. J. (2011). Sex, drugs, and sea slime: The oceans oddest creatures and why they matter. Chicago: University of Chicago Press. Walker, P., & Wood, E. (2005). People and the sea. New York: Facts on File. Read More