Convallatoxin

Convallatoxin is a cardiac glycoside found in plants of the Convallaria genus, most notably Convallaria majalis, commonly known as Lily of the Valley. It is one of several toxic compounds present in these plants, responsible for their poisonous nature. Convallatoxin acts by inhibiting the sodium-potassium ATPase pump in cell membranes. This inhibition leads to an increase in intracellular sodium concentration, which in turn affects calcium influx. The resulting elevation of intracellular calcium strengthens myocardial contraction, similar to the action of digitalis. However, this also makes the heart muscle more susceptible to arrhythmias. Ingestion of plants containing convallatoxin can cause symptoms ranging from gastrointestinal upset such as nausea and vomiting, to more severe cardiovascular effects including bradycardia (slow heart rate), tachycardia (fast heart rate), and potentially fatal arrhythmias. The glycosidic nature of convallatoxin means it is a sugar molecule attached to a steroid nucleus. While the plant has historical uses in traditional medicine, its toxicity necessitates extreme caution and it is not used therapeutically due to the narrow therapeutic window and the availability of safer alternatives. All parts of the Convallaria plant are considered toxic.