Castor Oil Plant ( Ricinus communis ). Prepared by: Dy , Alejandro Labasan , Kristin III-BSCT. Ricinus communis. Castor Oil Plant. Kingdom: Plantae Order: Malpighiales Family: Euphorbiaceae Genus: Ricinus Species: R. communis. Castor Oil Plant.
Species: R. communis
Castor seed is the source of castor oil, which has a wide variety of uses.
The seeds contain between 40% and 60% oil that is rich in triglycerides, mainly ricinolein.
The seed contains ricin, a toxin, which is also present in lower concentrations throughout the plant
The name Ricinus is a Latin word for tick
The common name "castor oil" probably comes from its use as a replacement for castoreum, a perfume base made from the dried perineal glands of the beaver
It has another common name, palm of Christ, or Palma Christi, that derives from castor oil's reputed ability to heal wounds and cure ailments.
The fruit is a spiny, greenish (to reddish-purple) capsule containing large, oval, shiny, bean-like, highly poisonous seeds with variable brownish mottling.
Castor seeds have a warty appendage called the caruncle, which is a type of elaiosome.
The caruncle promotes the dispersal of the seed by ants (myrmecochory).
Ricin is poisonous if inhaled, injected, or ingested, acting as a toxin by the inhibition of protein synthesis. It is resistant, but not impervious, to digestion by peptidases.
By ingestion, the pathology of ricin is largely restricted to the gastrointestinal tract where it may cause mucosal injuries; with appropriate treatment, most patients will make a full recovery.
It can be in the form of a powder, a mist, or a pellet, or it can be dissolved in water or weak acid
According to the 2007 edition of the Guinness Book of World Records, this plant is the most poisonous in the world
Ricin is classified as a type 2 ribosome inactivating protein (RIP)
Whereas Type 1 RIPs consist of a single enzymatic protein chain; Type 2 RIPs, also known as holotoxins, are heterodimericglycoproteins.
Type 2 RIPs consist of an A chain that is functionally equivalent to a Type 1 RIP, covalently connected by a single disulfide bond to a B chain that is catalytically inactive, but serves to mediate entry of the A-B protein complex into the cytosol
Both Type 1 and Type 2 RIPs are functionally active against ribosomes in vitro, however only Type 2 RIPs display cytoxicity due to the lectin properties of the B chain. In order to display its ribosome inactivating function, the ricin disulfide bond must be reductively cleaved.
Ricin A Chain (RTA) is an N-glycoside hydrolase composed of 267 amino acids. It has three structural domains with approximately 50% of the polypeptide arranged into alpha-helices and beta-sheets. The three domains form a pronounced cleft that is the active site of RTA.
Ricin B Chain (RTB) is a lectin composed of 262 amino acids that is able to bind terminal galactose residues on cell surfaces. RTB form a bilobal, barbell-like structure lacking alpha-helices or beta-sheets where individual lobes contain three subdomains. At least one of these three subdomains in each homologous lobe possesses a sugar-binding pocket that gives RTB its functional character.
Many plants such as barley have the A chain but not the B chain. People do not get sick from eating large amounts of such products, as ricin A is of extremely low toxicity as long as the B chain is not present.
The major symptoms of ricin poisoning depend on the route of exposure and the dose received, though many organs may be affected in severe cases
Initial symptoms of ricin poisoning by inhalation may occur within 8 hours of exposure. Following ingestion of ricin, initial symptoms typically occur in less than 6 hours
Inhalation: Within a few hours of inhaling significant amounts of ricin, the likely symptoms would be respiratory distress, fever, cough, nausea, and tightness in the chest. Heavy sweating may follow as well as fluid building up in the lungs (pulmonary edema). This would make breathing even more difficult, and the skin might turn blue. Finally, low blood pressure and respiratory failure may occur, leading to death.
Ingestion: If someone swallows a significant amount of ricin, he or she would vomitting and diarrhea that may become bloody. Severe dehydration may be the result, followed by low blood pressure.
Other signs or symptoms may include seizures, hallucinations, and blood in the urine. Within several days, the person's liver, spleen, and kidneys might stop working, and the person could die.
Skin and eye exposure: Ricin in the powder or mist form can cause redness and pain of the skin and the eyes.
Death from ricin poisoning could take place within 36 to 72 hours of exposure, depending on the route of exposure (inhalation, ingestion, or injection) and the dose received. If death has not occurred in 3 to 5 days, the victim usually recovers.
No Treatment Available
In 1978, Georgi Markov, a Bulgarian writer and journalist who was living in London, died after he was attacked by a man with an umbrella. The umbrella had been rigged to inject a poison ricin pellet under Markov's skin
Some reports have indicated that ricin may have been used in the Iran-Iraq war during the 1980s and that quantities of ricin were found in Al Qaeda caves in Afghanistan.