Pharmacognosy - 5.15 Oxytocics
Oxytocics
Oxytocics are drugs or substances that stimulate uterine contractions, often used to induce or augment labor, as well as to control bleeding after delivery. The most well-known oxytocic is oxytocin, a hormone that also plays a role in milk ejection. Other oxytocics include ergot alkaloids and prostaglandins.
Ergot
Synonym:
Ergot; Rye Ergot; Secale cornutum; Spurred rye; Ergot of rye; Ergota.
Biological Source:
Ergot is the dried sclerotium [hard dark resting body] of a fungus, Claviceps purpurea.
Family:
Clavicipitaceae [क्लॅव्हिसिपिटेसी].
Chemical Constituents:
A large number of indole alkaloids have been isolated from the Ergot. The most important alkaloids are ergonovine and ergotamine. On the basis of solubility in water the alkaloids are divided into two groups:
- Water-soluble ergometrine (or ergonovine) group:
- Ergometrine, Ergometrinine
- Water-insoluble (ergotamine and ergotoxine) groups:
- Ergotamine group: Ergotamine, Ergotaminine, Ergosine, Ergosinine
- Ergotoxine group: Ergocristine, Ergocristinine, Ergocryptine, Ergocryptinine, Ergocornine, Ertgocorninine
Chemically, ergot alkaloids are indole alkaloids that are peptide derivatives of lysergic acid.
Uses:
- Ergot is oxytocic, vasoconstrictor and abortifacient and used to assist delivery and to reduce post-partum haemorrhage [severe vaginal bleeding after childbirth.].
- Expelling the placenta after childbirth.
- Ergotamine is indicated as therapy to abort or prevent vascular headache (migraine).
Life cycle of Ergot
Ergot is a fungal growth. The life cycle of ergot contains three stages:
- Ascospore stage
- Asexual stage/Honey dew stage
- Sexual stage
1. Ascospore stage:
The sclerotia produced in late summer and fall on the ground. In damp condition these sclerotia germinate to produce small purple colour stalks(stroma), which on further growth form a flattened spherical head at the top. These head contain several flask shape cavities which are known as perithecia.
2. Asexual stage/Honey dew stage:
Each perithecium contains several elongated asci. Each ascus contains eight elongated thread like ascospores. These ascospores dispersed by air current. The dispersed ascospores entangled with the feathery stigmas of host and produce mycelia which penetrate the ovary. The mycelia give rise to conidia, produce from the surface of the ovary. The honey dew is sweet in taste and attract the insects. Along with honey dew, conidia are carried from one place to another by insects.
3. Sexual stage:
Hyphae penetrate deeply into the ovary and develop into a mass covering the entire ovary which results in the formation of elongated sclerotium. Sclerotium develops further and fall on the ground, and next cycle begins.