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Marine Natural Products for Human Health Care
Published in Hafiz Ansar Rasul Suleria, Megh R. Goyal, Health Benefits of Secondary Phytocompounds from Plant and Marine Sources, 2021
Ziconotide is a peptide consisting of 25-amino acid derived from the ω-conotoxin, a toxin from cone snail (Conus magus) found in tropical sea, [187]. The snails produce conotoxin for fish hunting to immobilize the prey by acting on the neuromuscular system [213]. In patients, ω-conotoxin acts by blocking the N-type voltage-sensitive calcium channels and inhibiting the neurotransmitters release thereby interrupting the nerve signal conduction leading to pain relief [212]. Since the large-scale production is limited due to the lack of enough biological specimens; and ziconotide was produced by peptide synthesis [5, 148].
Clinical Toxicology of Conus Snail Stings
Published in Jürg Meier, Julian White, Handbook of: Clinical Toxicology of Animal Venoms and Poisons, 2017
The very rapid onset of signs of paralysis in victims of Conus geographus envenomation compared to that in Elapidae snakebite victims (2 to 3 hours after the bite53) is probably due mainly to the difference in size of their neurotoxins. Conotoxins generally consist of 13 to 30 amino acids whereas snake neurotoxins have about 60 to 70 amino acids (post-synaptic) or substantially larger, sometimes with subunits (pre-synaptic). Conotoxins are also more tightly folded with an average of one disulfide bridge for every 6 to 10 amino acids compared to one disulfide bridge per about 15 amino acids in snake postsynaptic neurotoxins16,54. The small and tightly folded structure of conotoxins can therefore be more rapidly transported from the site of injection to the toxin target site. In addition, Conus venom contains many other peptides some of which like conopressin-S and conopressin-G have been suggested55 to act as accessory peptides in facilitating dispersal of the major toxins.
Molecular Mechanisms of Nociception
Published in Gary W. Jay, Chronic Pain, 2007
Conotoxin analogue ziconotide is a peptide derived from snail venom that blocks the entry of calcium into the neuronal voltage-gated calcium channels, which stops the conduction of nerve signals. These N-type voltage-gated calcium channels are found in the spinal cord dorsal horn. This drug is given intrathecally, for intractable pain (74,75).
Preparation of uniform-sized GeXIVA[1,2]-loaded PLGA microspheres as long-effective release system with high encapsulation efficiency
Published in Drug Delivery, 2022
Lu Li, Zhiguo Li, Yongxin Guo, Kai Zhang, Weidong Mi, Jing Liu
Currently, the drug of choice for the clinical treatment of chronic neuralgia is opioids. However, opioids are accompanied by a series of adverse reactions such as tolerance and addiction, and they are frequently administered, resulting in poor patient compliance, and there are certain limitations in clinical treatment (Angst & Clark, 2006; Chou et al., 2015; Devereaux et al., 2018). Conotoxin αO-GeXIVA, a 28-amino acid polypeptide found in the marine animal conus in the South country Sea, can achieve an analgesic effect by specifically blocking the α9α10 nAChR receptor, which has attracted widespread attention (Yu et al., 2018; Xu et al., 2020; Wang et al., 2019). Its isomer GeXIVA[1,2] is by far the most active conotoxin (Yousuf et al., 2022), showing excellent analgesic effects in many disease models (Vincler & Mcintosh, 2007; Alsharari et al., 2020; Khan et al., 2002). Notably, no addictive or motor side effects were observed during the treatment period. Therefore, GeXIVA[1,2], as a novel polypeptide compound with unique pharmacological and analgesic effects, is expected to be used in the clinic to improve the therapeutic effect of chronic neuropathic pain.
Postoperative pain: a review of emerging therapeutic options
Published in Expert Review of Neurotherapeutics, 2021
Abhishek K Gupta, Shayla Mena, Zhaosheng Jin, Tong J Gan, Sergio Bergese
Conotoxins are peptides found in predatory marine nails in the Conidae (‘cone snail’) family. Ziconotide is a synthetic ω-conotoxin peptide approved by the FDA and EMA for intrathecal delivery using a pump system. It selectively binds to N-type voltage-gated calcium channels found in the laminae of the spinal cord’s dorsal horn, blocking neurotransmission and modulation of nociception [151]. Compared to intrathecal morphine, ziconotide is not associated with hyperalgesia, hypogonadal effects, and withdrawal [152]. Side effects include dizziness, nausea, vomiting, nystagmus, confusion, urinary retention, and somnolence [153]. An analysis of three randomized, controlled trials in ziconotide monotherapy suggested benefit in reducing chronic, neuropathic pain [154]. Due to it’s high cost, narrow therapeutic window, and wide array of side effects ziconotide may be most useful in those who develop severe, chronic pain post-operatively.
Nature and applications of scorpion venom: an overview
Published in Toxin Reviews, 2020
Saadia Tobassum, Hafiz Muhammad Tahir, Muhammad Arshad, Muhammad Tariq Zahid, Shaukat Ali, Muhammad Mohsin Ahsan
Toxins interact with VGSCs in two ways. It either results in a blockage of pore when the neurotoxin physically obstructs the pore and inhibits the conductance of sodium ions, or in a modification of the gating, that altered the voltage-dependence and gating kinetics of the ion channels. Toxins that interact with the site 1 use first mechanism. For example, tetrodotoxin (TTX) and sexitoxin (STX) are pore blockers of site 1. Grayanotoxin and batrachotoxin are site 2 toxins which prevent inactivation and therefore, channel remain persistently active (Stevens et al. 2011). Scorpion α-toxins and sea anemone toxins bind to site 3 and inhibit the inactivation (Possani et al. 2000). Scorpion β-toxins and spider β-toxins are site 4 toxins which shift the activation toward hyperpolarized state (Shichor et al. 2002). Site 5 toxins like ciguatoxins and brevetoxins display a real effect upon binding with VGSC, for example, inhibition of activation and the hyperpolarizing shift of voltage-dependence activation. Finally, δ-conotoxins interact with site 6 and produce similar outcomes as the site 3 neurotoxins by inhibiting inactivation (Figure 3) (Stevens et al. 2011).