**Question:** Active component of a white oleander

**Core Concept:** White oleander (Nerium oleander) is a plant species that contains various bioactive compounds. The most significant compound responsible for its biological effects is the cardiac glycoside oleandrin.

**Why the Correct Answer is Right:** Oleandrin is a cardiac glycoside, a group of compounds that primarily affect the heart by inhibiting the sodium pump in the sarcoplasmic reticulum of cardiac muscle cells. This leads to a decrease in the uptake of calcium ions, which results in a reduced force of contraction and impaired relaxation of the heart muscle. Oleandrin can cause cardiotoxicity and is potentially lethal when consumed due to its interference with the normal functioning of cardiac cells.

**Why Each Wrong Option is Incorrect:**

A. **Nerium oleander:** This is the common name of the plant, but it does not specifically describe the active component.
B. **Nerium:** Similar to option A, this refers to the plant species but does not highlight the active compound.
C. **Oleander glycosides:** While true that oleander contains glycosides, this option is too broad and does not specify oleandrin as the active component.
D. **Glycosides:** Like option C, this term refers to the presence of glycosides in oleander but does not specify oleandrin as the active component.

**Clinical Pearl:** White oleander has been used traditionally as a medicinal plant, but its consumption can lead to severe cardiac toxicity and even death. It is essential for medical professionals, especially those in rural areas where this plant is abundant, to be aware of its potential dangers and educate patients and communities accordingly.

**Correct Answer:** D. Oleander glycosides

Oleander is a plant species that contains various bioactive compounds, including cardiac glycosides. The active component responsible for its toxic effects is oleandrin, a cardiac glycoside. Oleandrin interferes with the normal functioning of cardiac cells, leading to cardiotoxicity and severe health complications.