Jequirity bean, castor oil plant & Co. – exotic souvenirs can contain poisonous plant seeds

Beautiful and dangerous at the same time – this description applies to numerous poisonous plant seeds. Thanks to their colourfully appealing look, some seeds are also used as decora-tive elements in the manufacture of jewellery or decoration of musical instruments and toys. Such products can be found at bazaars and souvenir markets in some countries that are also popular with German tourists. By searching for a nice memento, holidaymakers are often unaware of the health risk that can come from these seeds.

One example is the jequirity bean, which has many other names depending on the country. Its seeds contain abrin – one of the most potent phytotoxins in the world. With 75 μg (mi-crograms), even a single seed contains enough abrin to induce severe poisoning in an adult. In children, a dose between 75 μg and 150 μg can lead to death, while in infants the lethal dose is significantly lower. Severe gastritis accompanied with vomiting, diarrhoea and cramps, kidney and circulatory failure with considerable dehydration, paralysis of the central nervous system and even death can occur after a few hours to two days.

If the seed is swallowed whole, the risk of poisoning is low due to the sturdy outer shell. If the shell is damaged, however, because it is pierced for jewellery making or mistakenly chewed in the mouth, the phytotoxin can be released. There is also a risk that people can mistake the seeds of the jequirity bean for other edible seeds. For example, a German tourist brought a colourful pepper mixture from Tunisia which turned out to contain jequirity beans.

Another example of poisonous plant constituents is the castor oil plant. Because of its col-oured leaves, it is often to be found in parks and gardens as a decorative ornamental plant. The problem here is that all parts of the plant,also known as “miracle tree” or “palm of Christ”, contain the strong poison ricin, for which the indications of poisoning are similar to those of abrin. The bean-shaped seeds of the plant are located in the spherical, prickly fruits and con-tain high levels of ricin. They are also used in jewellery manufacturing and can accidentally be mistaken for nuts, especially by children.

The lethal dose after oral intake is estimated to be in the range of 1mg/kg bw (milligrams per kilogram of body weight, which equates to around five to ten castor bean seeds) to 20 mg/kg bw. The intake of only a few (three to five) chewed castor bean seeds can cause fatal poi-soning in children.

The range of decorative “natural beads” from the fruits of legumes is extensive and also ap-plies to the seeds of other plants such as Ormosia, coral tree, Rhynchosia, mescal bean or the red sandalwood tree. For some plants, there is currently hardly any information on the toxic effects of the constituents contained (e.g. alkaloids).

For this reason, the German Federal Institute for Risk Assessment (BfR) advises tourists in particular to pay special attention when buying products decorated with plant seeds in exotic countries, or which they mistakenly believe to contain edible components, as in the case of the pepper mixture.

Link: https://www.bfr.bund.de/cm/349/jequirity-bean-castor-oil-plant-%26-co-exotic-souvenirs-can-contain-poisonous-plant-seeds.pdf