Ergot of Rye is a plant disease that is caused by the fungus Claviceps purpurea. The so-called ergot that replaces the grain of the rye is a dark, purplish sclerotium (Figs. 1a-b), from which the sexual stage (Fig. 2a-b), of the lifecycle will form after over wintering.
The sexual stage consists of stroma in which the asci and ascospores are produced. Although the ergot is far different in appearance than the true grain, its occurrence was so common that it was thought to be part of the rye plant, until the 1850’s, when the true nature of the ergot was understood.
Although the common name indicates that this fungus is a disease of rye, it also can infect several other grains, with rye being the most common host for this species. It is the ergot stage of the fungus that contains a storehouse of various compounds that have been useful as pharmaceutical drugs as well as mycotoxins that can be fatal when consumed. The proportion of the compounds produced will vary within the species. Thus, the victim that has lived through ergot poisoning once may experience different symptoms if they were unfortunate enough to consume ergot for a second time. This species was also the original source from which LSD was first isolated. It is believed that symptoms of ergotism have been recorded since the middle ages and possibly even as far back as ancient Greece.
There are approximately 35 species of Claviceps, with most occurring on grasses. All species form the sclerotium that is described above, and will form the same types of compounds. Although some research have been carried out in these other species, the bulk of our knowledge and most of our research has been concerned with Ergot of Rye.
Today, we will go over the consequences of consumption of the ergot stage of Claviceps purpurea and describe some of the impact that it has had.
Symptoms Caused By Consumption of Ergot of Rye
Poisoning attributed to Ergot of Rye is referred to as ergotism. Although this fungus is recognized as one species, there are two sets of symptoms that can be found in cases where serious poisoning as occurred: convulsive and gangrenous ergotism.
Convulsive ergotism is characterized by nervous dysfunction, where the victim is twisting and contorting their body in pain, trembling and shaking, and wryneck, a more or less fixed twisting of the neck, which seems to simulate convulsions or fits. In some cases, this is accompanied by muscle spasms, confusions, delusions and hallucinations, as well as a number of other symptoms.
In gangrenous ergotism, the victim may lose parts of their extremities, such as toes, fingers, ear lobes or in more serious cases, arms and legs may be lost. This type of ergotism causes gangrene to occur by constricting the blood vessels leading to the extremities. Because of the decrease in blood flow, infections occur in the extremities, accompanied by burning pain. Once gangrene has occurred, the fingers, toes, etc. become mummified, and will eventually fall off as a result of infection. If the infected extremities are not removed, infection can spread further up the extremity that has been infected. Gangrenous ergotism is common in grazing, farm animals. This link shows pictures of a cow in which the gangrenous ergotism has occurred in the ear and hooves.
Today, we will cover some examples of gangrenous and convulsive ergotism and the impact that it has had in different places and times.
Discovering The Cause of Ergotism
The Cultivation of Secale cereale (Rye) and the Origin of Ergotism
The occurrence of Claviceps purpurea must have began with the cultivation of rye since it was far more common on that host than in other grains. Rye was a weed grain and occurred wherever wheat was cultivated. Often it became the dominant plant when wheat fields were abandoned. Thus, in a way, where ever civilization became established, rye would follow it there. However, it was not cultivated for food until some time, in the early Middle Ages (around the 5th. Century), in what is now eastern Europe and western Russia. It was in the Rhine Valley, in 857 A.D., that the first major outbreak of gangrenous ergotism was documented. It was at this time that the symptoms (but not the knowledge of what caused the symptoms) from consumption of ergot was called Holy Fire. “Fire” because of the burning sensations, in the extremities, that were experienced by the victims of gangrenous ergotism, and “Holy” because of the belief that this was a punishment from God. The victims’ toes, fingers, arms and legs often became blackened as a result of gangrene, and would eventually die from the infections in these extremities. In addition, the victims often suffered from convulsive ergotism, as well, from the psychoactive properties that may occur in the ergo. Numerous epidemics of ergotism followed, with thousands dying as a result of the continual consumption of infected rye, with the most susceptible victims often being children.
In 1039, an outbreak of ergotism occurred in France. During this outbreak, however, a hospital was erected in order to care for the victims of ergotism, by Gaston de la Valloire. De la Valloire dedicated this hospital to St. Anthony, and through this gesture Holy Fire came to called St. Anthony’s Fire. Monks would eventually start the order of St. Anthony and over 370 hospitals would be built for those ailing from Holy Fire, in the name of St. Anthony. Each hospital was symbolically painted red to inform the illiterate that aide was available to help alleviate their pain. Those who came often did find relief from ergotism. This was probably due to the absence of rye bread from the victims’ diet during their care in the hospital. However, those inflicted by ergotism, and healed, were likely to be inflicted again since the cause of this strange disease was unknown.
Although there is no doubt that ergotism occurred in the Middle Ages, medicine was at a very primitive state at this time, and some of the symptoms that we associate with ergotism can be due to other illnesses. Thus, the outbreaks of ergotism couldn’t always be confirmed. However, it seems rather certain that by the 8th. and 9th. centuries, in the kingdom of the Franks, ergotism was present and would continue to be present in this area for the next eight hundred years. From the year 900 AD, when records evidently became common in what is now France and Germany, to around 1300 AD, there were severe epidemics of ergotism over large areas every five to ten years.
What is now France was the center of many of these severe epidemics because rye was the staple crop of the poor, and the cool, wet climate was conducive for the development of ergot. Ergot infection of rye was more likely during these wet periods because the rye flower remained opened longer, which provided more opportunity for the fungus to infect the flower. The regular rye grain and the hard, purplish black, grain-like ergot produced by the fungus were harvested and ground together during milling. The flour produced was then contaminated with the toxic alkaloids of the fungus. In 944 AD, in southern France, 40,000 people died of ergotism. Because the cause was unknown, no cure was available (you don’t have to known the cause of a disease to cure it, but it sure helps; also knowing the cause of a disease does not mean an immediate cure will be found). Until people realized that the consumption of ergot was the cause of the disease, there was no rational way by which treatment could proceed.
It was not until 1670 that a French physician, Dr. Thuillier, put forth the concept that it was not an infectious disease, but one was due to the consumption of rye infected with ergot that was responsible for the outbreaks of St. Anthony’s Fire.
Historical Events In Which Ergotism Was Involved
The plague of Holy Fire (gangrenous ergotism) was also responsible for some of the geographical boundary of Europe today. France suffered many waves of ergotism throughout its history beginning around the eight and ninth century and continuing for the next 800 years. During the one hundred years between 800-900 A.D., The Holy Roman Empire, which was formed by Pope Leo III, was one of those areas affected by Holy Fire. This was a part of Europe that was populated by the Franks and during this period thousands of peasants ate bread made from the infected grain and thousands died as a result of Holy Fire.
At the same time, from Scandinavia, a race of people, the Northmen (Vikings) invaded the Holy Roman Empire. With their superior size and fighting ability, and of course the fact that a large population of the Franks had just suffered from ergot poisoning, they easily defeated the Franks who lived along the coastal regions. Before this time, the Vikings had already settled permanently on the northwest coast of France and had already exerted pressure on the Holy Roman Empire with their numerous raids. Because of the constant successful raids in this area, Charles the Third was forced to abdicate the throne of the Holy Roman Empire by 887 and this led to the split of the Holy Roman Empire into two kingdoms. The kingdom of the West Franks became France and the kingdom of the East Franks became Germany. Through it all the Northmen were unaffected by the ergotism because Rye was not their staple food. By 911, the Northmen’s hold on the northwest coast of France was complete, and the king of France ceded to them what would become Normandy. The people that settled Normandy adopted the French religion, language and culture, and would eventually become assimilated by France. Today, Normandy is a part of France, but its recognition as a region is still recognized.
Without question the Northmen were warriors of superior size and fighting skill, but it is impossible to say how successful their invasion, against the Franks, would have been if the wave of ergotism had not occurred at this same time. However, it is difficult to imagine that with much of the Frank population sick with ergotism that they were able to put up much of a fight regardless of the fighting prowess of the invading army.
The Present Impact of Ergot
Through careful screening out of the ergot stage, ergotism is now rare. To clean Rye seeds, a floatation method has been devised. A solution of approximately 30% potassium chloride is poured over the Rye seeds and stirred. The ergot stage is buoyant and will float to the top and can be skimmed off and the seeds planted. To minimize the amount of ergot formation, after Rye has been harvested, the field is deeply ploughed so that the ergot will not germinate. A different crop can then be rotated the following year that is not susceptible to ergot, which will break the cycle of any ergot that may have survived the previous year’s ploughing. Unfortunately, there has never been a variety of Rye that has been developed that is resistant to ergot.
Current Uses of Ergot
There are medicinal products that have been extracted from Ergot. Some of the more common example include ergotamine, which is prescribed for various causes of headaches, including migraines. Ergonovine is used to control postpartum hemorrhage and cause contraction of the uterus. The knowledge that the ergot could be used for the latter was known since the 17th. Century when mid-wives prepared extracts of ergots for this purpose. In 1935, Albert Hofmann was able to synthesize ergonovine in the lab, at Sandoz Laboratories. The most well known is LSD, which was originally prescribed for psychiatric disorders, but was eventually made illegal due to abuse.
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