Is oleander really toxic? Understanding its toxicity in one article

Oleander is a well-known ornamental flower, an evergreen erect large shrub of the genus Nerium in the dogbane family (Apocynaceae). It is cultivated in all provinces and regions of China, especially in the south, and is often planted in parks, scenic areas, along roadsides, or around rivers and lakes. Its leaves resemble willow and bamboo, its red flowers blaze brilliantly, surpassing peach blossoms, and its corolla ranges from pink to deep red or white, giving it extremely high ornamental value. Now let us take a look at whether oleander is toxic!

Is oleander really toxic?

The entire oleander plant is highly toxic. Oleander is one of the most toxic plants, containing multiple toxins, some of which are even fatal. Its toxicity is extremely high, and there have been reports of small amounts causing death or near-death. The most abundant toxins among them are the cardiac glycosides oleandrin and neriine. Cardiac glycosides are natural plant or animal toxins that have both positive and toxic effects on the heart. They can be found in every part of the oleander, with the highest concentration in the sap, and can cause numbness on the skin. Moreover, scientists believe that oleander still contains many unknown harmful substances.

Medicinal value of oleander

[Nature and flavor] Bitter in taste, cold in nature, highly toxic.

[Meridian tropism] Heart meridian.

1. Root bark: Oleander root bark has cardiotonic and insecticidal effects, used for heart failure and epilepsy, and applied externally for paronychia and alopecia areata.

2. Leaves: Oleander leaves have cardiotonic, diuretic, expectorant and insecticidal effects, used for heart failure and epilepsy, and applied externally for paronychia, alopecia areata and killing flies.

3. Whole plant: The whole oleander plant has cardiotonic, diuretic, diaphoretic, expectorant, blood-stasis-dissolving, analgesic, detoxifying and rash-promoting effects, used for asthma, epilepsy, heart failure, killing flies and eliminating mosquito larvae.

Pharmacological effects of oleander

1. Cardiotonic effect: The leaves, stems, bark, wood and flowers of oleander all have relatively significant cardiotonic effects, with the leaves having the strongest effect.

2. Diuretic effect: Oleander infusion and alcohol extract show diuretic effects in experimental animals, but weaker than digitalis.

3. Sedative effect: Oleander decoction and alcohol extract have a sedative effect on experimental mice, manifested as reduced spontaneous activity and drowsiness, and can prolong barbiturate sleep time, but have no anticonvulsant effect. Its sedative effect appears after changes in heart rhythm.

4. Insecticidal effect: Oleander bark water extract and gum have insecticidal and molluscicidal effects. When the water extract and ethanol extract of oleander leaves are separated and refined, their toxicity to Lymnaea stagnalis is 14 times greater than the standard molluscicide niclosamide, and also superior to the molluscicides formothion and phorate.

5. Other effects: Oleandrin C has a relatively strong emetic effect and is relatively stable to heat. At low doses it inhibits uterine contraction and dilates blood vessels; at high doses it increases uterine muscle tension and contracts vascular smooth muscle. In addition, the leaves have an inhibitory effect on Ehrlich ascites carcinoma in mice.