Key Difference – Neurotoxin vs Hemotoxin
Before discussing the difference between neurotoxin and hemotoxin, let us first see the function of toxins. A toxin is a biologically active unique molecular entity, which can damage or kill a living organism through its action on specific tissues. These toxins can be categorized into two major groups such as neurotoxin and hemotoxin. Neurotoxins are chemical constituents that are poisonous or destructive to nerve tissue. Hemotoxins are chemical constituents that destroy red blood cells or cause hemolysis, interrupt blood clotting, and/or cause organ collapse and general tissue damage. This is the easily identified key difference between neurotoxin and hemotoxin; however, there are some other differences between neurotoxin and hemotoxin as well. This article will introduce you to neurotoxin and hemotoxin and the difference between neurotoxin and hemotoxin.
What is Neurotoxin?
Neurotoxins are constituents that are lethal or destructive to the nerve tissue. Neurotoxins act by a mechanism leading to either the interference or damage of necessary components within the nervous system. Since the nervous system in most living organisms is both highly complex and essential for survival, it has obviously become a target for attack by both predators and prey. Venomous or toxic living organisms frequently use their neurotoxins to subdue predators or to catch prey. Neurotoxins are a broad range of exogenous chemical neurological insults that can harmfully affect the function in both developing and mature nervous tissue. Although neurotoxins are regularly neurologically vicious, their ability to target precisely the neural constituents is significant in the study of nervous systems. Neurotoxins prevent neuron control across the cell membrane or interrupt communication between neurons across a synapse. In addition, neurotoxins can damage the central nervous system and peripheral nervous system. A number of treatments aimed at diminishing neurotoxin-mediated cell injury comprise of antioxidant and antitoxin administration.
What is Hemotoxin?
Hemotoxins (also known as haemotoxins or hematotoxins) are toxins that destroy red blood cells, disrupt blood clotting, and/or cause organ collapse and widespread tissue damage. The term hemotoxin is used as toxins that damage the blood as well damage other tissues. Damage from a hemotoxic constituent is regularly very painful and can cause permanent damage and in severe cases death. Loss of an affected limb is possible even with speedy treatment. Animal venoms/toxins comprise enzymes and other proteins that are hemotoxic or neurotoxic or sometimes both. In some reptiles, hemotoxic not only act as a venom but also aids in digestion; the venom can break down protein in the section of the bite, making the prey’s flesh easier to digest.
What is the difference between Neurotoxin and Hemotoxin?
The difference between neurotoxin and hemotoxin can be divided into following categories.
Definition of Neurotoxin and Hemotoxin:
Neurotoxin: Neurotoxin is a poison which acts on the nervous system.
Hemotoxins: Hemotoxins are toxins that destroy red blood cells, or it causes hemolysis, disrupt blood clotting, and/or cause organ collapse and tissue damage. This is also known as haemotoxins or hematotoxins.
Characteristics of Neurotoxin and Hemotoxin:
Origin of toxins:
Neurotoxin: Venomous or toxic living organisms use their neurotoxins to subdue a predator or prey mainly for their protection or for their consumption. In addition to that, due to environmental pollution, industrial activities and some heavy metals like neurotoxins are accidently discharged into the atmosphere. Some pathogenic microorganisms can also produce neurotoxins such as botulinum toxin.
Hemotoxins are often seen in venomous animals such as vipers and pit vipers.
Examples of Animals that release toxins:
Neurotoxin: Pufferfish, ocean sunfish and porcupine fish employ Tetrodotoxin neurotoxins. Scorpion venom contains Chlorotoxin. The diverse groups of cone snails use a range of different types of conotoxins. Botulinum toxin is produced by the bacterium Clostridium botulinum.
Hemotoxins: Toxins produced by snakes such as rattlesnakes, copper-head, cottonmouths vipers and pit vipers include hemotoxins.
Target systems and organs in the living organisms:
Neurotoxin: This can attack the central nervous system and peripheral nervous system, nervous tissue, inhibition of neurotransmitter (acetylcholinesterase) capacity.
Hemotoxins: This mainly attack red blood cells and important body tissues.
Signs, Symptoms, and Complications:
Neurotoxin: Damage to the central nervous system include intellectual disability, persistent memory impairments, epilepsy, and dementia. Peripheral nervous system damage due to neurotoxins such as neuropathy or myopathy cause paralysis.
Hemotoxins: Signs and symptoms include nausea, hemolysis, blood clotting, tissue damage, disorientation, and headache
Time required to onset of signs and symptoms and process of death:
Neurotoxin: The time necessary for the onset of symptoms is based on neurotoxin exposure that can vary between different toxins, being on the order of hours for botulinum toxins and years for lead.
Hemotoxins: Signs and symptoms can occur very rapidly after ingestion of hemotoxin into the blood. The process by which hemotoxin causes death is much slower than that of a neurotoxin.
Neurotoxin: Antioxidant and antitoxin administration can be used to treat this condition.
Hemotoxins: Antitoxin drug administration can be used to treat this condition.
Neurotoxin: Examples of Neurotoxin include lead, ethanol or drinking alcohol, Manganese, glutamate, nitric oxide (NO), botulinum toxin (e.g. Botox), tetanus toxin, organophosphates, and tetrodotoxin. Excessive concentrations of nitric oxide and glutamate also cause neuron damage. Neurotoxins can be further categorized based on the mechanisms of actions. Examples are;
- Na channel inhibitors – Tetrodotoxin
- Cl channel inhibitors – Chlorotoxin
- Ca channel inhibitors – Conotoxin
- K channel inhibitors – Tetraethylammonium
- Inhibitors of synaptic vesicle release such as Botulinum toxin and tetanus toxin
- Receptor inhibitors – Bungarotoxin and Curare
- Receptor agonists – 25I-NBOMe and JWH-018
- Blood-brain barrier inhibitors – Aluminium and mercury
- Cytoskeleton interference – Arsenic and ammonia
- Ca-mediated cytotoxicity – Lead
- Multiple effects – Ethanol
- Endogenous neurotoxin sources – Nitric oxide and glutamate
Hemotoxins: Viper venom
In conclusion, both neurotoxin and hemotoxin are life-threatening toxic compounds which are mainly derived from the venom of animals to protect them from preys as well as to facilitate their digestion. However, their mechanisms of action are completely different from each other because neurotoxins mainly target nervous system whereas hemotoxins mainly target blood cells and tissues.References: Leonard, B. E. (1986). Is Ethanol a Neurotoxin? the Effects of Ethanol on Neuronal Structure and Function, Alcohol and Alcoholism, 21 (4): 325–338. Meldrum, B. and J. Garthwaite, (1990). Excitatory Amino Acid Neurotoxicity and Neurodegenerative Disease. Trends in Pharmacological Sciences, 11 (9): 379–387. Radio, Nicholas M., and William R. Mundy, (2008). Developmental Neurotoxicity Testing in Vitro: Models for Assessing Chemical Effects on Neurite Out-growth. NeuroToxicology, 29: 361–276. Image Courtesy: “Crotalus horridus (1)” by Tad Arensmeier from St. Louis, MO, USA – Timber Rattlesnake. (CC BY 2.0) via Commons