Hippeastrum spp.


Botanical Name

Hippeastrum spp.

Synonyms

No documentation

Family

Amaryllidaceae [1]

Vernacular Names

English

Amaryllis, barbados lily, belladonna lily, cape belladonna, naked lady lilly, St. Joseph lily [1], resurrection lily [7]

Spain

Azucena, lirio, tararaco [1], azecena de Mejico [7].

Description

Hippeastrum spp. is a member of the Amarylidaceae family. There are about more than 75 species already described which mostly originated in South America. It is seasonal and perennial bulbous plants. The leaves have three to six leaflets, glossy strap-like, and measure about 10 cm long and 5 cm wide. Each plant is capable to produce one or two inflorescences. The inflorescence generates two to five (mostly four) big trumpet-shaped flowers, with hollow scape and grows up to 55 cm. The flowers are measure about 20 cm in diameter, zygomorphic, vary in colours from pure white to brilliant red with many colours and striped variations in between.  The flowers appear before or at the same time as the leaves emerge. The seeds are flattened with black papery wings. The hybrids of the species is continually being developed, thus the total species in the genus will be expanding [6] [7].

Distribution

This group of plants occured throughout the world as cultivated ornamentals [1].

Plant Use

Hippeastrum spp. are popular as ornamentals [1].

Toxic Parts

Bulbs [1].

Toxin

Lycorine and related phenanthridine alkaloids. Lycorine is a heat stable alkaloid. The bulb contain 0.1-1.0 % of the toxin [1].

Galantamine (galanthamine, galanthne, lycoremine) is one of several liliaceae alkaloids with anticholinesterase inhibitor activity that reverses the central actions of tropane alkaloids (hyosine, atropine). This compound is a phenanthrene alkaloid that has a chemical structure similar to codeine. This compound has substantially greater affinity for human erythrocyte acetyl cholinesterace than plasma acetyl cholinesterase, and the affinity of galantamine is about 10 times greater for human brain acetyl cholinesterase. Lycorine-type liliaceae alkaloids also exhibit acetylcholinesterase activity with 1-O-acetyllycorine being abour 2-fold more potent than galantamine [5].

The mechanism of the galantamine toxicity is that its long acting, selective, reversible, and competitive inhibitor of acetylcholinesterase. Galantamine potentiates nicotinic neurotransmission by allosteric modulation on nicotinic acetyl cholinesterase receptors as well as inhibiting acetylcholinesterase. Galantamine can penetrate the blood-brain barrier and augment cholinergic transmission [5].

Risk Management

For as long as theHippeastrum spp. bulb remains underground, it does not pose any danger to humans or animals. Upon digging it out, there is a danger of it being mistaken for onions [1] [2] [3].

Clinical Findings

Following ingestion of fairly large amounts, symptoms include nausea and persistent vomiting while diarrhoea is usually slight or absent. Ingestion of small amounts does not produce significant symptoms. Plants of these genera also cause both allergic and irritant dermatitis, particularly in florists and growers who are repeatedly exposed to these plants [1] [2] [3] [4]. Other symptoms include parasympathetic effects, such as salivation and blurred vision. Ingestion of lycorine is associated with profuse vomiting [5].

Hippeastrum spp. generally contains several active alkaloids, with the bulb being reported as toxic to humans. Typical symptoms include gastrointestinal upset leading to convulsions and death. The leaves however are nontoxic to mice, but the flowers were toxic to rats. Among the reported cases are the bulb of Hisppeastrum spp. hadcaused gastrointestinal upset with possible trembling, convulsions and death, blameable to the active alkaloid in the family. Meanwhile the bulbs of  H. equestre known to kill humans and animals in 2 to 3 hours, and H. vitata bulb ingested by three children caused one to vomited and fell asleep, but prompt stomach lavage avoided further effects which was due to its alkaloids, hippeastrine, lycorine and others existed in the bulb [3].

Management

Most exposures result in minimal or not toxicity. Intravenous hydration, antiemetics, and electrolyte replacement may be necessary for patients with severe gastrointestinal symptoms, particularly in children [1].

Treatment is supportive. Because gastrointestinal irritation is the major effect of ingestion of these bulbs, the patient should be evaluated for fluid and electrolyte balance as indicated by the clinical presentation. Decontamination measures are unnecessary because of the vomiting associated with poisoning by these bulbs [5].

References

  1. Nelson LS, Shih RD, Balick MJ, Handbook of Poisonous and Injurious Plants. Berlin: Springer-Verlag; 2007. p. 77-78
  2. Lynch JJ. Lippincott’s Manual of Toxicology Wolters Kluwer Health. Philadelphia: Lippincott Williams & Wilkins;  2012. p. 394.
  3. Kinghorn AD. Toxic Plants. New York: Columbia University Press; 1979. p. 118.
  4. Fuller TC. Poisonous Plants of California. Berkely: University of California Press; 1986. p. 268.
  5. Barceloux DG. Medical Toxicology of Natural Substances: Foods, Fungi, Medicinal Herbs, Plants and Venomous Animals. Hoboken, New Jersey: John Wiley & Sons; 2008. p. 713-714 
  6. Bajaj YPS, editor. High-Tech and Micropropagation VI. Berlin: Springer; 1997. p. 3
  7. Knight A. A Guide to Poisonous House and Garden Plants. Jackson, Wyoming: Teton New Media, Incorporated; 2007. p. 137.