Materia Medica

Passiflora incarnata, Passifloraceae.  The common name is passion flower, maypop or apricot vine.

Passiflora was discovered in 1569 by Spanish explorers in Peru. The ten-petal flower was seen as symbolic of the passion of Christ, and was considered as a sign of divine approval of the Spanish conquest.  The Incas brewed a tonic tea of the plant, and the usage soon spread to Europe, where it was used as a tranquilizer and mild sedative.  The American colonists on the Gulf Coast adopted its usage from the local Indians, who used it to soothe their nerves and topically as a poultice, the crushed leaves being used on cuts and bruises. 

The Eclectic physicians considered Passiflora an important remedy for insomnia, restlessness, menstrual discomforts, diarrhea, epilepsy and whooping cough.  They also used the leaf juice externally for burns, scalds, wounds and toothache.  It was recognized in the National Formulary from 1916 to 1936.

There are about 400 species of the genus Passiflora, some noted for their flowers and others for their edible fruit.  It is frequently grown as an ornamental.  Passiflora species are native to tropical and subtropical areas of the Americas.  Passiflora incarnata grow from Virginia to Florida and as far west as Missouri and Texas.  It is a fast-growing, climbing perennial vine that can reach 30 feet.  The flowers are white, tinged with purple and three inches across.  They produce egg-sized yellow or orange edible fruit.

The above ground parts of the plant are used.  It is available as bulk herb, teas, capsules, hydroalcoholic extracts, and is frequently mixed with other relaxant herbs such as valerian and skullcap.

Passiflora is used for its sedative, anxiolytic and antispasmodic effects.  It has not been determined just what the active constituents are, but flavonoids and alkaloids are most often cited as the most probable.   Passiflora has complex action on the central nervous system.¹  It has been found that there is a difference in effect between the alcohol extract and the aqueous extract.  The alcohol extracts proved to be anxiolytic and the aqueous extract more sedative in experiments with mice.²  Early studies indicated that it has musculotropic action.³  The German Commission E recommends it for nervous restlessness.⁴

In vitro experiments have shown Passiflora to be effective in killing a wide variety of molds, yeasts and bacteria.  Group A hemolytic streptococci are quite susceptible and Candida albicans is intermediate in susceptibility.  The antimicrobal activity is quickly lost in the dried plant.⁵

In common usage Passiflora is a popular herb for nervousness, anxiety, reducing pain and inducing sleep.  It is frequently used as an antispasmodic for spasms, epilepsy, menstrual pain, spasmodic coughing and asthma.⁶

The primary constituents of Passiflora are flavonoids, maltol, cyanogenic glycosides and indole alkaloids.  The indole alkaloids are harman, harmin, harmalin, harmol and harmalol, which can be MAO inhibitors, but are present in such small amounts that it is unlikely to have this effect.  The flavonoids (2.5%) consist of vitexin, isovitexin, orientin, isoorientin, apigenin, kampferol, vicenin, lucenin, saponarin and passiflorine (similar to morphine).⁷  It also has phenolic, fatty, linoleic, linolenic, palmitic, oleic and myristic acids, as well as formic and butyric acids, courmarins, phytosterols and essential oil.

The German Commission E recommends 4 to 8 gr. daily or the equivalent preparation.  Hydroalcoholic extracts are used at dosages of 10 to 60 drops.

Do not use during pregnancy due to the uterine stimulating action of the harman alkaloids.  Most reports consider it nontoxic.  It is possible that large doses can cause convulsions, CNS depression and decreased myocardial strength.⁸   The constituent maltol increases sleeping time induced by hexobarbital.⁹