From Seed to Seed:
Plant Science for K-8 Educators

Curare. Curare is manufactured from an alkaloid extracted from Chondodendron tomentosum, a vine native to South America. Curare was commonly used by hunters on their poison arrows; a small amount was sufficient to paralyze many prey animals. Curare interferes with nerve impulses, resulting in temporary paralysis. In low doses, it is a useful muscle relaxant during surgery.

Digitalis and digitoxin. These substances are derived from a familiar garden plant, the foxglove (Digitalis purpurea). Foxglove has been used to treat ailments for more than 3000 years-but because of toxicity at high doses, the treatments often did more harm than good. Only when an English physician investigated the plant's use in folk remedies and began experimenting on his own were its true medicinal properties discovered. This work paved the way toward its use in the treatment of heart disease.

In the case of foxglove, the active ingredients are not alkaloids-but rather the cardiac glycosides digitalis and digitoxin. These substances are useful in the treatment of congestive heart failure. By slowing and strengthening the heartbeat, they improve circulation and facilitate the removal of accumulated fluids from the patient's tissues.