What is colchicine?
Colchicine or ethyl trimethyl colchicine is an alkaloid from the autumn crocus, that works good for gout. The substance was previously used in the treatment of cancer. Now only sporadically the derivative democolcine is used for this.
The therapeutic width of colchicine, however, is small (that means that there is only a small difference between an active and a toxic dosage). The lethal (lethal) dose (LD50) amounts to approximately 20 mg for adults.
Also colchicine for Lily (Gloriosa superba) in the climb, even in a higher concentration than in autumn crocus, but the plant is hard to enhance, making a rewarding crop for the production of colchicine is not possible.
Colchicine mechanism of action
The action of colchicine in gout is based on the inhibition of the chemotaxis (attraction) of neutrophils (a type of white blood cell). This allows the inflammation that causes the symptoms of gout can not develop. Colchicine does not prevent the actual cause of gout, namely the deposition of uric acid crystals in the joint. The deposition of these crystals can be prevented by prescribing allopurinol. For this material inhibits the production of uric acid. Colchicine may also impede the functioning of the heart muscle.
Colchicine inhibits also by higher concentration in the polymerization of microtubules bind to tubulin. Tubulin is one of the main constituents of microtubules. The availability of tubulin is a basic prerequisite for mitosedeling. Because of this, colchicine acts as a mitotic poison. Mainly cancer cells are particularly vulnerable, since they are characterized by an increased mitotic activity. The therapeutic value of colchicine against cancer, however, is limited by the toxicity of the substance to normal cells. As a result, colchicine is no longer used as a tool for cancer. This mechanism does explain the low therapeutic index of colchicine.
With renal impairment, the dose should be reduced.
Off-label use
It is used successfully in familial Mediterranean fever. The dose is usually 0.5 mg 3 times daily. It is also been explored with success in the treatment of acute percarditis at a dose of 0.5 mg 2 times a day. It has also been studied successfully as a prophylactic agent against pericarditis
Plant
In plant breeding colchicine is used to artificially doubling the number of chromosomes. It is a so-called mitoseremstof, which prevents cell division at the transition from metaphase to anaphase, causing the formation of the spindle apparatus is blocked, and the chromosomes can not be pulled apart. By treatment with colchicine were tetraploid plants especially in the past been developed. For example tetraploid perennial ryegrass (Lolium perenne), which is used for sowing pasture. But also for the development of ornamental varieties of cut flowers. Hemp (Cannabis sativa) showed application of colchicine to be polyploid and thereby get a much stronger hallucinogenic effect.
History
Colchicine extract was first described as a remedy for gout in the Materia Medica by the pharmacologist Pedanius Dioscorides in the first century after Christ.
Colchicine was first isolated in 1820 by the French chemists PS Pelletier and J. Caventon. In 1883, Simon brought Zeisel clarify the chemical structure.
Still, it took a long time before an officially registered tablet 0.5 mg colchicine arrived in the Netherlands. In the US, the drug was only officially registered in 2009.