Daffodil (Narcissus pseudonarcissus) – Botany, Therapeutic Uses, Constituents, Pharmaco, Adverse Effects

It has been known for centuries that portions of the daffodil plant, the bulb in particular, affect central nervous system function. However, because it causes nausea and vomiting, daffodil is generally not taken orally. With the relatively recent discovery that a daffodil constituent is useful in the management of Alzheimer’s disease, this plant is an example of one that yields an agent useful for modifying central nervous system function even though the herb historically has not been used for that purpose. The clinical utility of daffodil also illustrates the value of alkaloids, a class of compounds produced by many plants. In fact, more alkaloids have been developed as prescription medications, or employed recreationally for their central nervous system effects, than flavonoids, the other major class of plant products. The discovery that daffodil produces a potent compound that can beneficially affect central nervous system function also demonstrates that plants are still a valuable source of new therapeutics.

The clinically active component of daffodil is the alkaloid galantamine, also known as galanthamine. Alkaloids are produced by plants, fungi, bacteria, and animals. The biochemical pathways for synthesizing these agents evolved to protect the plant from predators, as these compounds are often toxic. Thanks to its alkaloids, daffodil thrives as a species because its taste is unappealing and its consumption is potentially lethal to insects and others that may be interested in making it part of their diet. The alkaloid content of daffodil, and of other plant species, is generally quite small. However, because of their pharmacokinetic and pharmacodynamic properties, many alkaloids can, following oral consumption, readily accumulate in the brain where they interact with neurotransmitter systems. Because of their potencies, only small quantities are needed to have a significant behavioral effect. This explains why daffodils are so commonly and consistently seen sprouting in the same area of the lawn each year, whereas the appearance of other plants varies as a function of the local population of rabbits and other predators.

Plant alkaloids are a rich source of prescription and recreational drugs. Numbered among this chemical class are caffeine, nicotine, morphine, cocaine, quinine, and atropine. Mescaline, which is derived from a cactus, and psilocybin, which is produced by certain mushrooms, are hallucinogenic alkaloids that humans have used for centuries for religious and recreational purposes. This partial list of behaviorally active alkaloids illustrates the therapeutic potential of such compounds. Further evidence is provided by written records indicating that plants containing biologically active alkaloids have for more than 4,000 years been used as herbal remedies and poisons. The discovery that a common plant, such as daffodil, produces a clinically useful alkaloid is therefore not surprising. The fact that it took several millennia to appreciate its medicinal value is testimony to the difficulties sometimes associated with identifying a biologically active plant product with the chemical properties needed to be a useful drug.

The origin of the narcissus designation for this genus is a matter of dispute. Some claim the name derives from Narcissus, a character in Greek mythology. According to legend, because of his vanity and pride Narcissus showed only disdain for others. To punish him for such behavior, Nemesis, the Greek goddess of retribution, conspired to have Narcissus see his own reflection in a pond. He immediately fell hopelessly in love with what he saw. He was so transfixed with himself that he remained staring at the image until, according to one version, he died from starvation. It is said that narcissus plants first sprouted on the spot where he died. Others contend the plant name comes from the Greek word narcoun, which means to benumb. Narcoun is also the root for the term narcotic. According to this concept, the plant was called narcissus because consumption of the bulb depresses central nervous system function, not because of any relationship to Narcissus. There is more agreement on the origin of the word daffodil, the common name for Narcissus pseudonarcissus. It is thought that daffodil is a corrupted version of the Greek word asphodel, a flowery plant in the lily family. Regardless of its etymology, narcissus has been, and remains, a popular plant because of the beauty of its flower and ease of cultivation. Therapeutic value can now be added to this list of positive attributes.