Digitalis purpurea pharmacological forms, extracts of this plant did not frequently cause intoxication because they induced nausea and vomiting within minutes of ingestion, preventing the patient from consuming more. The main toxins in "Digitalis" spp. are the two chemically similar cardiac glycosides: digitoxin and digoxin. Like other cardiac glycosides, these toxins exert their effects by inhibiting the ATPase activity of a complex of transmembrane proteins that form the sodium potassium ATPase pump, (Na/K-ATPase). Inhibition of the Na/K-ATPase in turn causes a rise not only in intracellular Na, but also in calcium, which in turn results in increased force of myocardial muscle contractions.
Drug discovery products have often been used as the starting point for drug discovery. Until the Renaissance, the vast majority of drugs in Western medicine were plant-derived extracts. This has resulted in a pool of information about the potential of plant species as important sources of starting materials for drug discovery. Botanical knowledge about different metabolites and hormones that are produced in different anatomical parts of the plant (e.g. roots, leaves, and flowers) are crucial for correctly identifying bioactive and pharmacological plant properties. Identifying new drugs and getting them approved for market has proved to be a stringent process due to regulations