Kontakt 2011, 13(3):345-355 | DOI: 10.32725/kont.2011.040

Veratrum alkaloids: biology, chemistry, pharmacology and toxicologyBiomedicine - Review

Zdeňka Navrátilová^1,*, Jiří Patočka²

¹ Univerzita Karlova v Praze, Přírodovědecká fakulta, katedra botaniky

² Jihočeská univerzita v Českých Budějovicích, Zdravotně sociální fakulta, katedra radiologie a toxikologie

There are more than 200 Veratrum alkaloids that occur in plants of the genus Veratrum L. (Melanthiaceae), which includes a number of American, European and Asian hellebores (particularly the Veratrum viride Ait. and Veratrum album L.). The alkaloids are present in the rhizome and roots and in lower amounts also in seeds and other parts of the plant. The Veratrum alkaloids exert considerable cardiovascular and neuromuscular effects and also affect the respiratory system. They increase the cholinergic tone and decrease the adrenergic tone with relevant side effects, and in higher doses, they inhibit breathing and induce cardiac arrhythmia. Veratrum alkaloids have strong hypotensive effects, but only esterified alkaloids (of cerveratrine type) have been used in specific cases as agents reducing the blood pressure. Their high toxicity and adverse effects, particularly feeling sick and vomiting, made the treatment difficult and their use was thus discontinued even in spite of their attractive vasodilating effects. They were mostly stepwise replaced with medicines having lower undesirable effects. The plants of the genus Veratrum are currently being used as components of homeopathic products only.
Hellebores have long been known as very poisonous plants causing vomiting, chest pain, faints with weak pulse, cramps and death. They are also known as strong teratogenic substances; the sheep fed on them frequently delivered lambs with central eye. This congenital anomaly, in which the sheep has one eye only, is caused by one of veratrine alkaloids, 11-deoxojervine (cyclopamine), a unique natural product with fascinating history. Cyclopamine was the first discovered inhibitor of hedgehog signalling, which is currently considered as a key regulator in the embryonal period, where it controls processes such as the cell proliferation, differentiation and organ development. There is a possibility that understanding of the role of the hedgehog signalling pathway in the pathogenesis of the tumour development will result in a progress in new treatment procedures.

Keywords: Veratrum alkaloids; biology; chemistry; pharmacology; toxicology; hedgehog signalling

Received: July 11, 2011; Accepted: September 5, 2011; Published: September 29, 2011  Show citation