Nerium Oleander: The Beautiful Poisonous Flower
Overview
There are many different types of flowers with different characteristics across the globe. Whether wide, elongated or tiny, the different types of flowers are appreciated for their beauty, scent or what they represent for given cultures or societies etc. Nerium oleander, commonly known as Oleander, is one of the many plants in existent that produces some of the most beautiful flowers with colors ranging from white and cream to red.
Oleander
Other colors of the flowers
Pink
Lilac
Purple
Yellow
Nerium oleander
Nerium oleander is an evergreen shrub that remains gree in color throughout the year. As such, it is able to retain its foliage during warm climates compared to other deciduous plants. Classified under the family Apocynaceae, Nerium oleander can be found warm tropical and subtropical regions across the globe. For instance, they can be found in many parts of Southern United States, India, China and Australia among a few other countries. Although they grow well in environments that provide partial shade and well-drained soil, they are able to survive such harsh conditions as high salt content, strong winds, and poor soil quality. Because of their ability to survive harsh conditions, their beauty and the fact that they have a rapid growth rate, oleander plants are often used as ornamental plants in many parks, roadsides and parks.
Some of the characteristics of oleander include
Evergreen
Funnel-shaped flowers (with five petals)
Narrow, dark green leaves with a distinct midrib
The produce a clear gummy sap
Flowers are less than 2 inches in diameter
Flower
Toxic
Even when completely dry, ingestion of any part of the plant has been shown to result in digitoxin-like effects. This toxicity is caused by a variety of cardiac glycosides such as folinerin, oleandrin, rosagenin, and neriin. Apart from affecting the cardiovascular system, the toxins also affect the nervous system following ingestion. Apart from human beings, digitoxin-like effects have also been identified in such animals as cows (and other mammals) causing death within two days. The toxins, however, have been shown to have little effects on rodents and birds.
Oleandrin and neriin
Oleandrin
Oleandrin is one of the most common cardiac glycosides of oleander. Like other cardiac glycosides, oleandrin inhibits Na⁺ /K⁺ -ATPase, an enzyme that is typically found in the plasma membrane. This inhibition causes an increase in the concentration of intercellular calcium ions, which in turn results in a positive inotropic effect. While this impact may benefit some of the patients suffering from myocardial dysfunction (or poor heart rate) the toxin has been associated with various cardiac effects. By affecting normal cardiac activity, the toxin can cause an individual to experience a fatal heart attack. In cases where an individual may have ingested large amounts of any part of the plant, a high concentration of the toxin may severy affect cardiac activity ultimately causing death.
Neriin (nerrine)
Like Oleandrin, nerrin is a potent cardiac glycoside present in all parts of the plant. By inhibiting the activity of the Na+ − K+ pump (Na+ − K+ ATPase), the toxin can cause such dysrhythmias as a second or third-degree heart block/cardiac arrest several minutes after ingestion. Because of the toxin’s potency, it has been used in some cultures during hunting. In such cases, the substance is applied to the tips of hunting arrows for better results. Apart from ingesting any part of the plant (leaves, flowers, stem), smoke released from burning the plant also has similar effects on both human beings and some animals. As a result, toxicity effects have been observed among people who have used parts of the plant to roast fish and other smaller animals (meat).
Foliage
Clinical presentation of toxicity
Diarrhea
Sweating
General weakness
Severe gastroenteritis
Nausea and vomiting
Uses and application
While oleander can have negative health consequences on human beings and other mammals, it has a number of economic and medicinal importance. For instance, ground leaves and bark parts of the plant are used as insecticides and rat poison. In many regions where the plant is found, this application prevents rats and other insects from damaging crops and other foods in storage. On the other hand, the flowering part of the plant is used to produce a dye while the leaves are used to make rubber. However, given that the amount of latex obtained from the leaves is very little, the leaves are not used to produce large amounts of rubber.
The leaves and flowers of oleander have the following biological activities
Antioxidant activities
Diaphoretic
Cardiotonic
Anti-inflammatory
Antimicrobial
Anticancer activity
Larvicidal activity
Additional reading
Saabiya Farooqui and Tulika Tyagi. (2017). Nerium Oleander: Its Application in Basic and Applied Science: A Review.
Garima Zibbu and Amla Batra. (2010). A Review on Chemistry and Pharmacological activity of Nerium oleander L. Journal of Chemical and Pharmaceutical Research.
Links
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3841991/
https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/oleandrin
https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/cardenolides
https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/nerium
© 2019 Patrick
Comments
AUTHORHi Peggy, Thank you for sharing. I've never really come across the plant, so it's all from reading on my part. I read that toxicity is dependent on the amount ingested and type of animal. I will expand on clinical application of the plant soon.
Thank you for sharing.
These types of oleanders grow beautifully in our area and are seen frequently in home gardens as well as along highways where they are planted. Interesting information to know about the anti-cancer benefits as well as the other uses. As to the toxicity, we never had any problems with our dogs chewing on the oleanders and getting sick. Supposedly the bitter taste would dissuade them from doing so, at least that is what I read from one source.
