5. Foxglove: Heart Helper
The woolly foxglove plant produces digoxin, a cardiac glycoside that strengthens heart contractions. This medicine treats heart failure and controls irregular heartbeats in atrial fibrillation patients. Its narrow therapeutic window requires careful dosing to prevent toxicity. Doctors have used foxglove derivatives since the 18th century when William Withering documented its benefits for dropsy, or edema. Modern purification techniques now ensure consistent potency in pharmaceutical preparations.