- Slides: 14
Microbial Toxin-BIOC 422 Lecture-16
3 - Fungal Toxins
Fungal toxins I. Mycotoxins: Ø Major mycotoxins • Aflatoxins • Citrinin • Ergot Alkaloids • Fumonisins • Ochratoxin • Patulin https: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 164220/
I. Mycotoxins: Ø Major mycotoxins 2). Ergot Alkaloids Fungal toxins What are Ergot Alkaloids? Ø Ergot alkaloids, in general, are mycotoxins produced by several species of fungi in the genus Claviceps. Ø Ergot fungus contains a number of harmful substances collectively called the ergot alkaloids. What is alkaloids? § Alkaloid is an active nitrogen containing basic compounds of plant origin. § They are produced within various organisms as a secondary metabolite. Secondary metabolites are most commonly produced in plants as a defence system. The alkaloids produced by fungi are often toxic. The plants use alkaloids as defense chemical agents against herbivores and pathogens. The fungi produce alkaloids such as Ergotamine, Ergometrine, Ergonaline and various other Clavine alkaloids, are often toxic. . http: //www. apsnet. org/edcenter/intropp/topics/Mycotoxins/Pages/Ergot. Alkaloids. aspx https: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 164220/
Fungal toxins 2). Ergot Alkaloids What are Ergot Alkaloids? What is Ergot? • Ergot “or ergot fungi” refers to a group of fungi of the genus “Claviceps”. ü The most prominent member of this group is (Claviceps purpurea): ü Claviceps purpurea contaminates rye and wheat >> it produces *alkaloids substances called *ergotamines https: //www. ncbi. nlm. nih. gov/pmc/articles/PMC 164220/ http: //www. apsnet. org/edcenter/intropp/topics/Mycotoxins/Pages/Ergot. Alkaloids. aspx
Fungal toxins 2). Ergot Alkaloids What are Ergot Alkaloids? What is Ergotamine? • Ergotamine is one of the alkaloids that is produced by Claviceps purpurea • It has the biological activity as a vasoconstrictor. . (which means it constricts the blood vessels and thus the blood flow) • Ergotamine, in a proper dose, has been used in medicine: Ø For the treatment of acute migraine attacks. Ø They have also been used and misused to induce abortion. Ø It has been used to prevent post-partum hemorrhage (bleeding after child birth). • In excess, ergotamine can cause>> Ergot poisoning in humans and domestic animals that is known as Ergotism
Fungal toxins 2). Ergot Alkaloids What are Ergot Alkaloids? What is Ergotism? • Ergotism is a severe reaction to ergot-contaminated food • A condition that develops from ergotamines, substances produced due to fungal contamination of grains. ** It is the effect of long-term (chronic) ergot poisoning, traditionally due to the ingestion of the alkaloids produced by the Claviceps purpurea fungus “ergotamines” that infects rye and other cereals, and more recently by the action of a number of ergotmines-based drugs.
Historical Significance Ergotism Because of the burning pain (dry gangrene), it was known as (holy fire) and (hell's fire), and was one of the causes of St. Anthony's fire. http: //www. apsnet. org/edcenter/intropp/topics/Mycotoxins/Pages/Ergot. Alkaloids. aspx
Historical Significance/ Ergotism http: //botit. botany. wisc. edu/toms_fungi/oct 99. html Anthony’s popularity as a saint reached its height in the Middle Ages. The Order of Hospitallers of St. Anthony was founded near Grenoble, France (c. 1100), and this institution became a pilgrimage centre for persons suffering from the disease known as St. Anthony’s fire (or ergotism).
Historical Significance/ Ergotism http: //homepages. rpi. edu/~caporl/home/Notes_files/Satan%20 Loosed. pdf
Fungal toxins 2). Ergot Alkaloids What are Ergot Alkaloids? What is Ergotism? • Before this disease was understood, the ergots were ground up along with rye grains and ingested when the flour was used for baking. • The symptoms can be roughly divided into: i. Convulsive symptoms: include seizures and effects on the central nervous system that range from hallucinations to psychotic episodes. ii. Gangrenous symptoms: are a result of vasoconstriction induced by the alkaloids. Peripheral systems, such as fingers and toes, are typically affected.
2). Ergot Alkaloids Fungal toxins What are Ergot Alkaloids? What is Ergotism? • Ergotism (ergot poisoning) is currently very rare, but was more common in centuries past, as the ergot fungus grows well on grain, particularly rye, which is kept in moist conditions. • The fungus is not destroyed by milling or cooking (although it is destroyed by refining), so cooked whole grain products can also be contaminated. • Persons who ingest ergot suffer similar hallucinogenic effects of LSD “lysergic acid diethylamide”, plus because the dose is typically higher than what is used for recreational purposes, it also results in heightened physical symptoms which often vary greatly depending on the patient. • Such symptoms can result in the death of the patient if the dose is large and the symptoms are severe. • Antidepressants can suppress the effect of the LSD, but the symptoms will disappear in time if the patient is not exposed further.
Fungal toxins 2). Ergot Alkaloids What are Ergot Alkaloids? What is Ergotism? What is the possible side effect of using medicine Ergot-derivative? • There is a high risk of poisoning, and it can be fatal. • Ergot poisoning can progress to gangrene, vision problems, confusion, spasms, convulsions, unconsciousness, and death. • Some people have extra reasons not to use it: ü Pregnancy and breast-feeding: It’s UNSAFE to use ergot. Ergot has many effects that can be harmful during pregnancy and breast-feeding. ü Heart disease: Ergot can narrow blood vessels and make heart disease worse. ü Kidney disease: People with kidney problems are not able to flush ergot out of their bodies well enough. This can cause ergo to build up, and that increases the risk of ergot poisoning. ü Liver disease: People with liver problems are not able to remove ergot from their bodies well enough. This can cause ergo to build up, and that increases the risk of ergot poisoning.