Nerium Oleander

By Minnie W. Shuler, MS

A member of the dogbane family, Oleander is a familiar landscaping shrub especially in Florida.  It is of the genius Apocynaceae and is toxic in all of its parts being one of the most poisonous of commonly grown garden plants.  It is so widely cultivated worldwide that it’s specific region of origin is not identified but it is most often assigned to southwest Asia.  Oleander is potentially deadly to most mammals, and is a particular threat to livestock.  It is, however, not without virtue.  Aside from its beauty, oleander has proven medicinal uses.  It should not be used by an amateur because it is so dangerous but has been used for many years in homeopathic and many herbal systems of medicine.  Topical use shows little if any toxic effect.  During research on the plant an accidental discovery was made.  The plant provided an extract (NAE-8) that helped reduce the effects of aging on the skin.  (Nerium Biotechnology, Inc.)  “We had a eureka moment in our research labs when we stumbled upon what Nerium oleander could do for skin” Dennis Knocke.

Among the toxic compounds of oleander are two cardiac glycosides: oleandrin and oleandrigenin which can be therapeutic but also toxic when ingested in the wrong amounts.  Studies are being made to measure safe levels of dosage of the toxins.  These pre-clinical studies, which also include oral dosing of oleandrin, were conducted in preparation for an investigational drug submission to the U.S. Food and Drug Administration to allow for administration of the oleander extract to patients with cancer.^[18] 

The "cardiac glycosides", are known to increase cardiac contractility and have been traditionally used for treatment of congestive heart failure in China. In correct dosages, they are also used as anti-arrhythmic agents to control atrial fibrillation. Additionally, recent research has determined that small quantities of these glycosides are responsible for stimulating effects on the immune system in cancer patients.^[16]

Despite their potential for what could be serious side-effects, application of Nerium oleander cardiac glycosides applied intramuscularly (IM) and orally to combat cancers is now being investigated.^[18][19][25] The National Cancer Institute has defined oleandrin, one of the principal glycosides in Nerium oleander as "A lipid soluble cardiac glycoside with potential antineoplastic activity."

After evaluating all safety and toxicity data, the U.S. Food and Drug Administration determined that a defined Nerium oleander extract is safe enough to be administered to humans by mouth, and a defined Nerium oleander extract is now being used to treat cancer patients under an FDA-approved Investigational New Drug application.^[18] At this time the Nerium oleander extract has been administered to over 100 people by injection or mouth at total IM doses of from 0.5 mL to 2.25 mL and oral doses of 0.6 to 10.2 mg/day, for treatment of cancer, with no substantial negative side effects.^[18][19]

Historically, Nerium oleander has been reported in ancient texts and folklore for more than 1500 years. Used traditionally by herbalists as a folk remedy for a wide variety of maladies and conditions, including dermatitis, abscesses, eczema, psoriasis, sores, warts, corns, ringworm, scabies, herpes, skin cancer, asthma, dysmenorrheal, epilepsy, malaria, abortifacients, emetics, heart tonics, and tumors. It has been used extensively for medicinal purposes in Mediterranean and Central and Southern Asian countries, although these applications also have their basis in folk medicine and efficacy has not been documented by clinical research. Macerated leaves of oleander have been applied topically for treatment of dermatitis, loss of hair, superficial tumors and syphilis.^[24] A decoction of oleander leaves has been used for the treatment of gingivitis and as a nose drop for children.  One of the more interesting current uses is for venomous snake bite.

Reactions to this plant are as follows: Ingestion can cause both gastrointestinal and cardiac effects. The gastrointestinal effects can consist of nausea and vomiting, excess salivation, abdominal pain, diarrhea that may or may not contain blood, and especially in horses, colic.^[5] Cardiac reactions consist of irregular heart rate, sometimes characterized by a racing heart at first that then slows to below normal further along in the reaction. The heart may also beat erratically with no sign of a specific rhythm. Extremities may become pale and cold due to poor or irregular circulation. Reactions to poisonings from this plant can also affect the central nervous system. These symptoms can include drowsiness, tremors or shaking of the muscles, seizures, collapse, and even coma that can lead to death. Oleander sap can cause skin irritations, severe eye inflammation and irritation, and allergic reactions characterized by dermatitis.^[26]

People have been poisoned by using the woody stems of oleander as skewers to barbeque foods.  If you have small children who like to pick flowers or pets or livestock that might eat the plant, it is not a good choice for your yard.  It is, however, classified as a low flammable and suitable to plant next to the house for fire resistance.