Botanical Name

Thevitia peruviana (Pers.) K.Schum [4]

Synonyms

Cascabela thevetia (Linn.) Lippold, Cerbera thevetia Linn., Cerbera peruviana  Pers., Cascabela peruviana (Pers.) Raf, Thevetia linearis Raf,Thevetia neriifolia Juss. ex Steud, Ahouai thevetia (L.) Moza, Thevetia thevetia (L.) Millspaugh. [4]

Family

Apocynaceae

Vernacular Names

Description

Thevetia peruviana is a member of the Apocynaceae family. It is a shrub or small tree that can reach a height of 8 m. The branchlets have gray bark and white latex. The leaves are arranged spirally, simple, entire and almost sessile. The blade is linear-lanceolate 6 – 15 cm x 0.5 -1 cm with the base decurrent into the short petiole and apex that is long-acuminate. It is leathery with lateral veins obscure. Inflorescence is terminal or axillary cyme. The flowers are few with small linear bracts. They are bisexual, regular, faintly fragrant. The sepals are ovate, 1 cm lomg, acute and spreading. The corolla tube is trumpet-shaped. The fruits are fleshy drupes. They turn yellow then black upon ripening. [1] [2]

Distribution

It is native of Tropical America and West Indies. Today it is distributed widely as an ornamental plant. [3]

Plant Use

Eventhough it is known to be poisonous, but this does not hinder people from using it beneficially. The oil extracted from the seeds are used in treating burns and infected wounds. The bark, leaves, roots and seed forms part of various formulations for bladder stones, oedema, fevers, insomnia, haemorrhoids, malaria and even snakebites. A long time ago the Malays used juice of the leaves mixed with meat as bait to kill nuisance tigers.  [2]

Toxic Parts

Whole plant including the latex. The seed kernel contains the highest concentration of the toxins. [1] [2] 

Toxin

At least 8 different cardiac glycosides of the cardenolide type.  The poison affects the cardiovascular system and the gastrointestinal tract. Thevetin is the bitter principle with potent cardiac action similar to digitalis and 1/8 the strength of ouabain. It also affects the smooth muscles of the intestinge, bladder, uterus and vascular walls. Other cardiac glycosides isolated from the plant include thevetoxin, neriifolin, peruvoside and ruvoside. They have similar effects as thevetin on the smooth muscles of the intestine, bladder, uterus and blood vessels and heart. [1] [2] [3]

Risk Management

Serious effects of poisoning from ingestion of parts of this plant should be a deterrent for use of this plant in any landscape project. It has been reported that the fruits had been taken is suicidal attempts in certain society of the tropics.[1] [2] [3]

Clinical Findings

Initial symptoms of ingestion of the seeds or leaves are dryness, numbness and burning in the mouth, and throat, followed by abdominal pain, vomiting, and diarrhoea. Subsequent to this, there is dilatation of the pupils, dizziness, slow and irregular heartbeat with high blood pressure. Death may ensue due to heart failure. There may be a delay of up to 24 hours for symptoms to appear. Lethal dose in children is 1 – 2 seeds while in adults more than 8 seeds can prove fatal. The sap can cause skin irritation with blistering.  [1] [2] [3]

Management

Immediate treatment include gastric lavage and giving activated charcoal to the patient. The cardiac function should be frequently monitored through ECG and serum potassium level. Electrolyte monitoring and replacement may be needed. The use of atropine, lidocaine or even propranolol may be required based on levels of toxicity to the heart.  The use of anti-digoxin-specific Fab antibody fragments had been advocated, however, cost is a limiting factor for this form of therapy. [1] [2] [3]

Read More

  1)  Botanical Info

References

1. Schmelzer GH, Fakim AG. Plant Resources of Tropical Africa – Medicinal Plants 1 – PROTA pg.607 – 607
2. Nellis DW. Poisonous Plants & Animals of Florida and the Caribbean, Pineapple Press, Sarasota, 1997 pg. 146 – 147.
3. Burrows GE., Tyri RJ., Toxic Plants of North America, John Wiley & Sons, Oxford 2001 pg. 106 – 107.
4. Hanelt P. Mansfeld’s Encyclopedia of Agricultural and Horticultural Crops, Springer, Berlin 2001, pg. 1745