What Is Ergot? Causes, Symptoms, and Prevention in Biology
Let’s know the meaning of ergot. Ergot is a fungus that grows on rye and, to a lesser extent, other grasses such as wheat.
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Ergot has a fascinating history. A severe reaction to ergot-contaminated food (such as rye bread) known as ergotism, was common during the Middle Ages and was known as St. Anthony's fire. Furthermore, some historians believe that ergot played a role in the 1692 Salem witch hunt. They believe that eating ergot-contaminated food caused some women in Salem to develop strange behaviours and accuse other women of being witches.
Ergot has been used as a medicine despite serious safety concerns. Ergot has many uses, it is used to treat excessive bleeding during menstruation, to expel the placenta after childbirth, and for a variety of other conditions, but there is no good scientific evidence to keep up these claims.
Where is Ergot Obtained From?
Ergot alkaloids are extracted from the ergot fungus Claviceps purpurea, which grows on rye plants. These fungi are responsible for ergot of rye, a fungal disease that affects plants. The sclerotia of ergot fungi contain alkaloids that are used to make LSD, the full form of LSD is Lysergic acid diethylamide drugs that act on the CNS (Central nervous system).
They are natural hallucinogens that alter mood, behaviour, and thoughts in the same way that psychosis does, a condition in which thoughts and emotions are altered to the point where contact with reality is lost.
Ergot Alkaloids and Toxicity of Ergot Alkaloids
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Ergot alkaloids can be defined as a large group of compounds produced by fungi during the growing season that attack a wide variety of grass species, including small grains. Chemically, these compounds are classified as clavine alkaloids, lysergic acids, simple lysergic acid amides, and peptide alkaloids. Ergotamine and ergovaline are two common alkaloids found in ergot.
Toxicity - Ergotism is one of the oldest known mycotoxicoses, with historical evidence of its occurrence. The human epidemics caused by ergot in the Middle Ages known as St. Anthony's fire, with symptoms of gangrene, central nervous and gastrointestinal effects, were one of the most widely publicised events. Animals are affected in the same way that humans have been.
Ergot alkaloids have been linked to agalactia in pigs. Ergot is known to cause the loss of ears and other appendages in animals. Ergotism is classified into two types: gangrenous and convulsive.
The differences could be due to the different types of alkaloids found in ergot, as there can be variations in the amount and types of alkaloids found in ergot (sclerotia). Recent outbreaks have occurred in Ethiopia (1978), where gangrene and limb loss occurred, and in India (1975), where the effects were more nervous in nature, with giddiness, drowsiness, nausea, and vomiting.
Ergot of rye
Ergot of rye is caused by a lower fungus namely Claviceps purpurea that lives as a parasite on rye and, to a lesser extent, other grain species and wild grasses. Infested with this fungus kernels turn into light-brown to violet-brown curved pegs (sclerotia) that protrude from the husk in place of normal grains. The variety used medicinally is rye ergot (Secale cornutum).
Ergot Poisoning
Ergotism is a type of poisoning caused by eating grains infected with the ascomycete fungus Claviceps purpurea. Individual grains are replaced by the infection with dark, hard ergots, which are mixed in with the healthy grain during harvest and milling.
Life Cycle of Ergot
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The following phases represent the life cycle of ergot fungi in general, let’s go through the phases :
Phase 1 - Ascospores are carried to the host by the wind (this mainly takes place in spring)
Phase 2 - The spores attach to the host's pistil surface.
Phase 3 - As they germinate, the hyphae grow into the ovary organ - It is important to note that the hyphae only invades the plant's ovary and does not spread to other parts of the plant. The reason for this is unknown at this time.
Phase 4 - The fungi's conidia phase, the sphacelial stroma, continues to grow and develop in the organ (ovary)
Phase 5 - More spores are produced in the ovary, resulting in what appears to be a thick fluid that can then spread to other plants via a variety of dispersal methods (rain, insects etc)
Ergot Fungus
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Ergot, also known as ergot fungi, is a fungus genus of the genus Claviceps. Claviceps purpurea is the most well-known member of this group. This fungus grows on rye as well as related plants and produces alkaloids that can cause ergotism in humans and other mammals who eat grains contaminated with its fruiting structure.
Ergot Disease
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Ergot is known to be a fungal disease caused by fungi in the Claviceps genus. This genus' species are unique in that they only infect the host plant's ovaries; no other parts of the plant are infected. Claviceps is made up of about 40 different species, with C. purpurea and Tulasnella being the most dangerous.
FAQs on Ergot: Toxicity, Life Cycle, and Effects
1. What is ergot and what is its biological source?
Ergot is the dried sclerotium (a compact mass of fungal mycelium) of the fungus Claviceps purpurea. This fungus belongs to the Ascomycetes class and is a parasite that primarily grows on the flowers of rye and other cereal grains like wheat and barley. The dark, hard sclerotium replaces the grain kernel of the host plant.
2. What are the main medicinal uses of ergot alkaloids?
Ergot alkaloids, when purified and used in controlled doses, have significant medicinal applications. Key uses include:
- Ergotamine: Used to treat acute migraine attacks due to its ability to constrict blood vessels in the brain.
- Ergometrine (or Ergonovine): Used in obstetrics to control postpartum haemorrhage (bleeding after childbirth) by causing uterine contractions.
- Bromocriptine: A semi-synthetic derivative used to treat Parkinson's disease, pituitary tumours, and type 2 diabetes.
3. What is ergotism and what are its primary symptoms?
Ergotism, historically known as St. Anthony's Fire, is a disease caused by consuming grains contaminated with ergot fungus. The toxic alkaloids cause two main types of symptoms:
- Gangrenous Ergotism: This is caused by the vasoconstrictive effects of the alkaloids, which reduce blood flow to the extremities. It leads to a painful burning sensation, swelling, and can result in the loss of limbs due to gangrene.
- Convulsive Ergotism: This affects the central nervous system, causing symptoms like painful muscle spasms, seizures, diarrhoea, and psychiatric disturbances such as mania or psychosis.
4. How can the alkaloids in ergot cause both medicinal effects and toxic poisoning?
The dual effect of ergot alkaloids is primarily a matter of dosage, purity, and specific action. In medicine, specific alkaloids are isolated and administered in precise, low doses to target certain receptors (e.g., serotonin or dopamine receptors) for a therapeutic effect, like constricting cranial blood vessels for migraines. Toxic poisoning, or ergotism, occurs from consuming a mixture of alkaloids in high, uncontrolled doses from contaminated food. This leads to a systemic, widespread effect on the body, causing severe vasoconstriction (gangrene) and central nervous system overstimulation (convulsions) rather than a targeted medicinal benefit.
5. Is ergot itself a hallucinogen?
Ergot itself is not considered a hallucinogen and is highly toxic. However, it contains the chemical foundation for one of the most powerful hallucinogens. The fungus produces alkaloids like ergotamine, from which lysergic acid can be extracted. This lysergic acid is the direct precursor used in the laboratory to synthesise the potent psychedelic drug Lysergic Acid Diethylamide (LSD). Additionally, one of the symptoms of convulsive ergotism can be hallucinations.
6. How is the fungus Claviceps purpurea related to the drug LSD?
The relationship is direct and chemical. The fungus Claviceps purpurea naturally produces a variety of ergot alkaloids. One of the core chemical structures within these alkaloids is lysergic acid. In 1938, chemist Albert Hofmann synthesised Lysergic Acid Diethylamide (LSD) by chemically modifying this naturally occurring lysergic acid. Therefore, the ergot fungus is the original biological source for the key precursor required to manufacture LSD.
7. From a biological perspective, why does the fungus produce toxic ergot alkaloids?
The production of ergot alkaloids is a highly effective evolutionary survival strategy for the fungus. These compounds act as a potent chemical defence mechanism. Their toxicity deters herbivores, such as insects and grazing animals, from eating the fungal sclerotia. By preventing its consumption, the fungus ensures that its overwintering structure (the sclerotium) survives intact and can germinate in the following spring to infect new host plants, thus completing its life cycle.
8. Which crops are most commonly affected by ergot, and how can contamination be identified in a field?
The crop most famously and severely affected by ergot is rye. However, other cereal grains and grasses can also be hosts, including wheat, barley, oats, and triticale. Contamination is identified visually in the flowering heads of the grain. The fungus replaces a developing grain kernel with its own sclerotium, which appears as a hard, dark purple to black, often curved or horn-shaped structure that is typically larger than the actual grain.
