What is the main toxic principle found in oleander?

Oleander contains cardiac glycosides as its main toxic principle. Cardiac glycosides are a group of compounds that have a profound effect on the cardiovascular system. They are known to inhibit the sodium-potassium ATPase enzyme, leading to an increase in intracellular calcium levels in cardiac cells. This mechanism enhances the contractility of the heart muscle but can also be toxic, leading to arrhythmias and potentially fatal outcomes if ingested in sufficient quantities.

The lethal effects of oleander are primarily due to these cardiac glycosides, which can cause symptoms such as vomiting, diarrhea, abdominal pain, and disturbances in heart rhythm. The severity of toxicity can depend on the dose ingested and the amount of cardiac glycosides that the body absorbs. Understanding this toxic principle is crucial for veterinarians and pet owners, especially since oleander is a common ornamental plant and can pose a risk to pets if ingested.