Family: Compositae
Genus: Silybum
Species: marianum
(i) General background on the plant
A spiny biennial herb growing to 150 cm with white-veined leaves and purple flowerheads. The fruits are hard skinned achenes 6 to 8 mm long, shiny and brownish in colour. The flowerheads are harvested in full bloom in early summer and the seeds are collected in late summer. The plant is native to the Mediterranean and grows throughout Europe. Milk thistle prefers a sunny position and self-seeds readily. It is rare in the UK.
(ii) Details of quality characters
Mowrey (1988) considered milk thistle seeds to possess anti hepatic activity of a liver-protective herb.
The fruits of S. marianum contain silymarin, a mixture of flavonolignans (1.5-3%), and other compounds such as tyrosine, histamine, essential oil, lipids, sugars, alkaloids, vitamins C, E, and K. Flavonoids in the seeds are now known to be effective as antidotes to severe liver breakdown resulting from ingesting Amanita spp. (Death Cap mushroom), being able to displace phalloidin from membrane receptors.
(iii) Current production and yields.
(iv) Constraints on production
(v) Markets and market potential
S. marianum is a medicinal plant, which has been widely used in traditional European medicine. German research from the 1970s onwards has focused on silymarin contained in the seeds. This exerts a highly protective effect on the liver, maintaining function and preventing damage from compounds that are normally highly toxic. Nowadays silymarin, the purified extract of the fruits of S. marianum and its main constituent silymarin, are used in the treatment of diseases of the liver, for example it has been used successfully to treat hepatitis and liver cirrhosis. It is also used to treat conditions where the liver is under stress for example from infections, excess alcohol or from chemotherapy prescribed to treat cancer.
Milk thistle is the main remedy used in western herbal medicine to protect the liver and its many metabolic activities.
Silymarin also has some cosmetic applications.
(vi) Other information
Since 1975, silymarin and, in particular silybin have been the subjects of numerous biochemical and pharmacological studies which are still ongoing and which have provided the support for the clinical introduction of the active ingredient of S. marianum.
(vii) Contacts
(viii) References
Clapham, A.R., Tutin, T.G and Warburg, E.R. 1993. Excursion flora of the British Isles. Cambridge University press.
Mowrey, D.B. 1988 Guaranteed potency herbs. Next Generation Herbal Medicine. Cormorent Books. USA.
Morazzoni, P. and Bombardelli, E. 1994. Silybum marianum . FITOTRAPIA Vol. LXVI, No. 1, 1995. Italy.