Which item is included as a major plant toxicity category?

• A. Grayanotoxins
• B. Antibiotics
• C. Pesticides
• D. Heavy metals

Answer: (B)

Toxins that come from plants form distinct groups, and grayanotoxins are a classic example of a major plant-derived toxin category. These compounds occur in certain Rhododendron-related plants and can contaminate honey; they alter voltage-gated sodium channels, keeping them open and disrupting normal nerve and heart conduction. That mechanism underlies the characteristic GI upset and cardiovascular signs seen with exposure, making grayanotoxins a well-established plant toxin category. Antibiotics are not plant-produced toxin classes, and pesticides or heavy metals are toxicants with broader origins and aren’t defined as a primary plant-toxin category.