Ergot alkaloids are considered to be metabolites and produced by various members of the genus Clavicipitaceae. These contain the characteristic four membered ergoline rings which are also considered as precursor to Lysergic acid or even its derivatives. The list includes clavinet alkaloids, amides of lysergic acid and ergo-peptines. Various ergot alkaloid producing fungi produces different subsets of alkaloids and are very well known for their toxicity, especially ergotamine and ergovaline. These molecules are incorporated with lysergic acid.
The ergot alkaloids are associated with endophyte infected grass and the perennial rye grass in some parts of the world. Moreover, animals grazing these fields having the grass with alkaloid toxicities results in increased occurrence of ergot alkaloid levels in animal body tissues. Grasses can also become infected with claviceps where alkaloids are responsible for the ergotism.
The chemistry which deals with the alkaloids always looks into the part where these sub species are checked for their chemical structure and specific characteristics. The ergot alkaloids originate from a type of fungus which grows on rye. Although they contain several active pharmacological substances like histamine, tyramine, ergosterol and acetylcholine but the main basic chemical groups of ergot alkaloids are ergotamine, ergotoxine and ergonovine group.
All these have one thing in common and that is the presence of lysergic acid. The ergotoxine and ergotamine groups fall under the amino acid alkaloid and this is mainly due to the presence of amide nitrogen which contains the amino acid product of condensation. The ergonovine and alkaloids like di hydro-ergotamine possess a saturation of the double bond present at carbon 9 and carbon 10. This property helps in reducing the smooth muscle contracting action and also enhances the vaso – dilating properties.
The medicinal properties of ergot are mainly due to the presence of alkaloids. These were isolated the first time by Tanret in 1875 from ergotinine crystallisee. The first chemically pure ergot alkaloid, ergotamine was isolated in 1918. By now we have around 40 alkaloids isolated from ergot fungus. The ergot alkaloids are basically divided into two groups.
- Amide derivative of lysergic acid
- Clavine alkaloids
The lysergic acid amides can be further divided into two groups as simple amides and cyclic amides. Among the simple lysergic amides, the ergometrine is the most important alkaloids which is used for therapeutic purpose. The medically important peptide alkaloids ergotamine and ergotoxine group. The wide variation of alkaloids are now extensively used in medicine. However the total contribution of alkaloids in pharmacy industry is less than 1%.
Ergot consist of the dried claviceps which is a type of fungus which grows in rye plant. The ergot usage is dated back to 11th century and is also held responsible for the cause of medieval gangrene. The gangrene condition clearly showed the ingestion of ergot infected rye products.
The modern usage of ergot and its scientific use is restricted to its alkaloid action and especially the oxytocin action of ergot. The naturally occurring ergot alkaloid are derived from a tetracyclic structure of quinine – indol named the ergoline. These can be subdivided into two classes of the basis of the chemical structure. One is lysergic acid forms along with their precursor while the other is the Clavine alkaloids having ring structure of ergoline but lack carboxyl. These have no medicinal value.
Oxytocic or the ergot alkaloid helps in stimulate uterine contractions and since uterine walls are vascular in nature the muscles extend in all direction. These extend vertically, obliquely and horizontally as well. Oxyticin is the hormone secreted by posterior pituitary gland which causes uterine contraction and labor. The ergot alkaloid increase the frequency and force of uterine contractions.
The prostaglandins are natural hormones involved in regulating myometrium and natural induction of labor and stimulation. The synthetic oxytocin which helps in stimulation of smooth muscle can help in lactation and vasopressor effects.
While ergot alkaloid related incidence are not very common in humans but occasional pharmaco overdose do happen. More broad aspects of ergot alkaloid derived problems continues to remain as the specific physical properties of livestock systems. The impact of ergot alkaloid has now taken a global footprints. And moreover, it also effects a lot on agriculture sector and related industries. If the fungi which helps in synthesizing ergot alkaloid was known in medieval period then the knowledge of the cure was also known as far as 1100 BC. The primary aspect limiting progress which is attributed to ergot alkaloid interactions comes from the fact that these are also linked to alkaloid production.
The plant alkaloid which is symbiotic with the immediate surroundings and the overall environment influence can affect the production of alkaloid. In addition to plant fungus environmental interactions, there is another kind of interactions as well which goes on with the grazing animals. These also raises the alkaloid productions. The consumption of ergot alkaloid contaminated food gives rise to interactions in gut with the microbes present and finally affect the entire food chain.
The biological activity of ergot alkaloid absorbed in the body of the concerned animal is defined by structural similarity of these compounds to the amines which are present in biogenic units.
The ergot alkaloid interacts with
- serotonergic receptors
- adrenergic receptors
- dopaminergic receptors
If pure form and standards are applied the validation of extraction and its analysis ensures reliable results. A multi discipline approach is very much needed to solve most ergot alkaloid related issues.
There are many ergot alkaloids and their synthetic derivatives which are used mainly for their endocrine inducing actions are ergonovine, methyl ergonovine and bromo criptine.
Ergots are characteristically hard and pigmented dark. The medicinal use of ergot alkaloids is quite old and as per record ergots were used even during Mesopotamia reign.
The ergot alkaloids contain a wide spectrum of interesting pharmacological activities and are considered as prime source of various forms of drugs.
Most common ergot alkaloids uses are as follows:
- Post-partum haemorrhage prevention: ergometrine and methyl ergometrine
- Migraine treatment and various other forms of headache by using methyl lysergide
- Formulation of the di hydro derivatives of the ergo toxin is used for treating hypertension of aged patients.
- Hallucinating agents like LSD which are also derived from these materials
- The ergot alkaloids are showing good prospect in treating Parkinson disease
- This is also considered as an good treatment agent for breast cancer