While plant toxins are primarily evolved to deter herbivores and pathogens, they can also be toxic to humans. However, not all plant toxins are harmful at low doses; some have been harnessed for medicinal purposes. For example, digitalis, derived from the foxglove plant, is used in heart medications, and quinine from the cinchona tree is used to treat malaria. The dose-response relationship is crucial in toxicology, as the same compound can be therapeutic in small doses and toxic in larger quantities.
