Colchicine is an anti-inflammatory medication used to treat Gout and Behçet's diseaseplugin-autotooltip__plain plugin-autotooltip_bigBehçet's disease

"Behçet’s Syndrome (also known as Behçet’s Disease or, simply, Behçet’s) is a chronic condition resulting from disturbances in the body’s immune system. This system, which normally protects the body against infections by producing controlled inflammation, becomes over-active and results in unpredictable outbreaks of unwanted and exaggerated inflammation. This extra inflammation particularly affects blood vessels of all sizes, including arteries and veins. As a result, symptoms…. Sold under the brand names Colcrys, Mitigare, Gloperba and many others.

It was originally isolated from a herbal remedy - the Autumn Crocus plant - in use for at least 3,000 years to reduce joint swelling.

There are currently more than 2 million prescriptions per year in the US alone, and it's now a generic medicine in the UK.

There are at least seven different theories currently under investigation to try to show how it works - none of which has been accepted as a full explanation. It's suggested that it might :

• inhibit microtubule polymerization by binding to its constitutive protein, tubulin
• inhibit mitosis, as availability of tubulin is essential to mitosis,
• inhibit activation and migration of neutrophils to sites of inflammation
• interfere with the inflammasome complex found in neutrophils and monocytes that mediate interleukin-1β activation, a component of inflammation
• inhibit superoxide anion production in response to urate crystals
• interrupt mast cell and lysosome degranulation
• inhibit release of glycoproteins that promote chemotaxis from synovial cells and neutrophils

Source : Wikipedia

A full explanation may include any of the above - perhaps in combination(s). Or there may be an as yet undiscovered mechanism of action.