Toxins are often distinguished from other chemical agents strictly based on their biological origin.[7]
Less strict understandings embrace naturally occurringinorganic toxins, such asarsenic.[8][9][10] Other understandings embrace synthetic analogs of naturally occurring organic poisons as toxins,[11] and may[12] or may not[13] embrace naturally occurringinorganic poisons. It is important to confirm usage if a common understanding is critical.
Toxins are a subset oftoxicants. The term toxicant is preferred when the poison isman-made and therefore artificial.[14] The human and scientific genetic assembly of a natural-based toxin should be considered a toxin as it is identical to its natural counterpart.[15] The debate is one oflinguistic semantics.
The word toxin does not specify method of delivery (as opposed tovenom, a toxin delivered via a bite, sting, etc.).Poison is a related but broader term that encompasses both toxins and toxicants; poisons may enter the body through any means - typicallyinhalation,ingestion, orskin absorption. Toxin, toxicant, and poison are often used interchangeably despite these subtle differences in definition. The termtoxungen has also been proposed to refer to toxins that are delivered onto the body surface of another organism without an accompanyingwound.[16]
A rather informal terminology of individual toxins relates them to the anatomical location where their effects are most notable:
On a broader scale, toxins may be classified as eitherexotoxins, excreted by an organism, orendotoxins, which are released mainly when bacteria arelysed.
The term "biotoxin" is sometimes used to explicitly confirm the biological origin as opposed to environmental or anthropogenic origins.[17][18] Biotoxins can be classified by their mechanism of delivery aspoisons (passively transferred via ingestion, inhalation, or absorption across the skin),toxungens (actively transferred to the target's surface by spitting, spraying, or smearing), orvenoms (delivered through a wound generated by a bite, sting, or other such action).[16] They can also be classified by their source, such asfungal biotoxins,microbial toxins,plant biotoxins, or animal biotoxins.[19][20]
Biotoxins vary greatly in purpose and mechanism, and can be highly complex (thevenom of thecone snail can contain over 100 uniquepeptides, which target specific nerve channels or receptors).[22]
Necrotoxins causenecrosis (i.e., death) in the cells they encounter.[23] Necrotoxins spread through the bloodstream.[citation needed] In humans,skin andmuscle tissues are most sensitive to necrotoxins.[citation needed] Organisms that possess necrotoxins include:
Neurotoxins primarily affect the nervous systems of animals. The group neurotoxins generally consists ofion channel toxins that disrupt ion channel conductance. Organisms that possess neurotoxins include:
Myotoxins are small, basicpeptides found insnake andlizardvenoms, They cause muscle tissue damage by a non-enzymatic receptor based mechanism. Organisms that possess myotoxins include:
Many living organisms employ toxins offensively or defensively. A relatively small number of toxins are known to have the potential to cause widespread sickness or casualties. They are often inexpensive and easily available, and in some cases it is possible to refine them outside the laboratory.[24] As biotoxins act quickly, and are highly toxic even at low doses, they can be more efficient than chemical agents.[24] Due to these factors, it is vital to raise awareness of the clinical symptoms of biotoxin poisoning, and to develop effective countermeasures including rapid investigation, response, and treatment.[19][25][24]
The term "environmental toxin" can sometimes explicitly include synthetic contaminants[26] such as industrialpollutants and other artificially madetoxic substances. As this contradicts most formal definitions of the term "toxin", it is important to confirm what the researcher means when encountering the term outside of microbiological contexts.
Environmental toxins fromfood chains that may be dangerous to human health include:
In general, when scientists determine the amount of a substance that may be hazardous for humans, animals and/or the environment they determine the amount of the substance likely to trigger effects and if possible establish a safe level. In Europe, theEuropean Food Safety Authority produced risk assessments for more than 4,000 substances in over 1,600 scientific opinions and they provide open access summaries of human health, animal health and ecological hazard assessments in their OpenFoodTox[37] database.[38][39] The OpenFoodTox database can be used to screen potential new foods for toxicity.[40]
The Toxicology and Environmental Health Information Program (TEHIP)[41] at theUnited States National Library of Medicine (NLM) maintains a comprehensive toxicology and environmental health web site that includes access to toxins-related resources produced by TEHIP and by other government agencies and organizations.[42] This web site includes links to databases, bibliographies, tutorials, and other scientific and consumer-oriented resources. TEHIP also is responsible for the Toxicology Data Network (TOXNET),[43] an integrated system of toxicology and environmental health databases that are available free of charge on the web.
^"U.S. Code". Retrieved20 May 2022.the term "toxin" means the toxic material or product of plants, animals, microorganisms ...or a recombinant or synthesized molecule...
^"Module 1: Introduction to Toxicology"(PDF).Agency for Toxic Substances and Disease Registry. Retrieved20 May 2022.arsenic, a toxic metal, may occur as a natural contaminant ... or ... as a by-product of industrial activities. If the second case is true, such toxic substances are referred to as toxicants, rather than toxins.
^Goldblat, Jozef (30 June 1997)."The Biological Weapons Convention – An overview". Retrieved20 May 2022.The Convention applies to all natural or artificially created toxins, "whatever their origin or method of production" (Article I). It thus covers toxins produced biologically, as well as those produced by chemical synthesis
^abNelsen, David R.; Nisani, Zia; Cooper, Allen M.; Fox, Gerad A.; Gren, Eric C. K.; Corbit, Aaron G.; Hayes, William K. (2014). "Poisons, toxungens, and venoms: Redefining and classifying toxic biological secretions and the organisms that employ them".Biological Reviews.89 (2):450–465.doi:10.1111/brv.12062.PMID24102715.S2CID207101679.
^Vale C, Alfonso A, Vieytes MR, Romarís XM, Arévalo F, Botana AM, Botana LM (March 2008). "In vitro and in vivo evaluation of paralytic shellfish poisoning toxin potency and the influence of the pH of extraction".Analytical Chemistry.80 (5):1770–6.doi:10.1021/ac7022266.PMID18232710.
^Oikawa H, Fujita T, Saito K, Satomi M, Yano Y (2008). "Difference in the level of paralytic shellfish poisoning toxin accumulation between the crabs Telmessus acutidens and Charybdis japonica collected in Onahama, Fukushima Prefecture".Fisheries Science.73 (2):395–403.doi:10.1111/j.1444-2906.2007.01347.x.S2CID22926782.
^Abouabdellah R, Taleb H, Bennouna A, Erler K, Chafik A, Moukrim A (April 2008). "Paralytic shellfish poisoning toxin profile of mussels Perna perna from southern Atlantic coasts of Morocco".Toxicon.51 (5):780–6.Bibcode:2008Txcn...51..780A.doi:10.1016/j.toxicon.2007.12.004.PMID18237757.
^Wang L, Liang XF, Zhang WB, Mai KS, Huang Y, Shen D (November 2009). "Amnesic shellfish poisoning toxin stimulates the transcription of CYP1A possibly through AHR and ARNT in the liver of red sea bream Pagrus major".Marine Pollution Bulletin.58 (11):1643–8.Bibcode:2009MarPB..58.1643W.doi:10.1016/j.marpolbul.2009.07.004.PMID19665739.
^Wang L, Vaquero E, Leão JM, Gogo-Martínez A, Rodríguez Vázquez JA (2001). "Optimization of conditions for the liquid chromatographic-electrospray lonization-mass spectrometric analysis of amnesic shellfish poisoning toxins".Chromatographia.53 (1): S231–35.doi:10.1007/BF02490333.S2CID97937094.
^Mouratidou T, Kaniou-Grigoriadou I, Samara C, Kouimtzis T (August 2006). "Detection of the marine toxin okadaic acid in mussels during a diarrhetic shellfish poisoning (DSP) episode in Thermaikos Gulf, Greece, using biological, chemical and immunological methods".The Science of the Total Environment.366 (2–3):894–904.Bibcode:2006ScTEn.366..894M.doi:10.1016/j.scitotenv.2005.03.002.PMID16815531.
^Doucet E, Ross NN, Quilliam MA (September 2007). "Enzymatic hydrolysis of esterified diarrhetic shellfish poisoning toxins and pectenotoxins".Analytical and Bioanalytical Chemistry.389 (1):335–42.doi:10.1007/s00216-007-1489-3.PMID17661021.S2CID21971745.
^Morohashi A, Satake M, Murata K, Naoki H, Kaspar HF, Yasumoto T (1995). "Brevetoxin B3, a new brevetoxin nalog isolated from the greenshell mussel perna canaliculus involved in neurotoxic shellfish poisoning in new zealand".Tetrahedron Letters.36 (49):8995–98.doi:10.1016/0040-4039(95)01969-O.
^Morohashi A, Satake M, Naoki H, Kaspar HF, Oshima Y, Yasumoto T (1999). "Brevetoxin B4 isolated from greenshell mussels Perna canaliculus, the major toxin involved in neurotoxic shellfish poisoning in New Zealand".Natural Toxins.7 (2):45–8.doi:10.1002/(SICI)1522-7189(199903/04)7:2<45::AID-NT34>3.0.CO;2-H.PMID10495465.
