Passifloraceae (Plant Family)
Indigenous to the tropical regions of North America, passionflower is now
cultivated throughout Europe. This plant was supposedly given the name
passionflower because its corona resembles the crown of thorns worn by Christ
during the crucifixion.
The dried flowering and fruiting tops of passionflower are used in
traditional herbal remedies for nervousness, insomnia, and convulsion. During
the early twentieth century, this plant was a popular sedative and calmative,
and was listed in the United States National Formulary between 1916 to 1936. In
1978, the U.S. FDA banned the use of passionflower in OTC preparations, citing
the lack of valid evidence to support its safety or efficacy in the treatment of
nervousness or insomnia.
A survey conducted in 1986 indicated that passionflower was utilized more
frequently in Britain than any other ingredient in herbal sedatives. In Germany,
Commission E has approved the use of this herb as a tranquilizer. Commission E's
decision was based on evidence showing that passionflower reduced mobility in
laboratory animals. A number of sedative-hypnotic pharmaceutical preparations
sold in Europe, including a sedative chewing gum, contain passionflower extract.
Scientific research confirms that passionflower has an in vivo
motility-inhibiting effect. However, the active principles responsible for this
effect have not been unequivocally established. Passionflower contains
C-glycoside flavonoid constituents and small quantities (up to 0.01%) of
harmala-type indole alkaloids. The sedative effects are presumably not due to
these compounds, however, since harmala-type alkaloids tend to act as stimulants
rather than depressants.
Passionflower is a perennial climbing vine with herbaceous shoots and a
sturdy woody stem that grows to a length of nearly 10 m. The three-lobed leaves
are alternate, petiolate, and finely serrated. The flowers are
characteristically yellow or flesh-colored, with tinges of purple and a sweet
fragrance. Each flower has five petals varying in color from white to pale red.
Inside the petals is a secondary corolla composed of four thread wreaths. These
form rays that surround the axis of the flower. The ripe fruit is an
orange-colored, multi-seeded, ovoid berry containing an edible, sweetish yellow
Part Used/Pharmaceutical Designation
- Other: above-ground (aerial) parts;
Flavonoids (up to 2.5%): C-glycosylflavones (isovitexin-2"-glucoside,
schaftoside, isoschaftoside, isoorientin, isoorientin-2"-glucoside, vicenin-2,
lucenin-2), apigenin, luteolin glycosides (e.g., orientin, homoorientin,
lucenin); kaempferol, quercetin, rutin. Cyanogenic glycosides: gynocardine (less
than 0.1%). Indole-type alkaloids (up to 0.01%): harman, harmaline, harmalol,
harmine, harmol (putative constituent). Other constituents: maltol (0.05%),
ethylmaltol, passicol (a polyacetylene), fatty acids, formic acid, butyric acid,
sitosterol stigmasterol, gum, volatile oil (trace). Root contains coumarins
(scopoletin and umbelliferone).
Passionflower commercial preparations are made from the fresh or dried aerial
parts. Both whole and cut raw plant material are used in teas and infusions. For
optimal results, flowering shoots, growing 10 to 15 cm above the ground, are
harvested after the first fruits have matured and then either air-dried or
hay-dried. Some (but not all) experts recommend collecting the shoots two times
each year to coincide with maximum quantity of flavonoids. The content of harman
alkaloids also fluctuates, and plant material containing more than 0.01% harman
alkaloids should be avoided.
Traditional uses: used internally as sedative, mild hypnotic, antispasmodic,
and anodyne (analgesic) for nervous agitation, insomnia, hysteria, diarrhea,
dysentery, neuralgia, generalized seizures, nervous tachycardia, spasmodic
asthma, dysmennorhea; used externally for hemorrhoids. Also incorporated into
Conditions: nervousness, insomnia
Clinical applications: nervous restlessness and agitation, insomnia,
nervous gastrointestinal conditions
In in vitro studies, passicol, one of the main active constituents in
passionflower, showed antimicrobial action against several pathogens, including
bacteria such as hemolytic Streptococci and Staphylococcus aureus,
yeasts such as Candida albicans, and molds.
Several experiments have clearly demonstrated that passionflower has
psychotropic activity. In in vivo studies, passionflower extract and some of its
constituents significantly prolonged sleeping time and decreased
locomotor activity. An in vivo investigation evaluated the effects
of lyophilised hydroalcoholic and aqueous extracts of passionflower as well as
its active principles on behavioral parameters in mice. While the hydroalcoholic
extract exhibited anxiolytic (anti-anxiety) effects, the aqueous extract showed
sedative action. The aqueous extract also extended sleeping time in mice
previously given a sub-hypnotic dose of pentobarbital.
Maltol is a pyrone derivative isolated from an alkaloid fraction of
passionflower. Japanese researchers reported that maltol produced depression and
other sedative effects in mice. In other animal studies, a high dose of maltol
and ethylmaltol exhibited anticonvulsant effects while a low dose of these same
compounds reduced spontaneous motor activity. Both maltol and ethylmaltol had
sedative action on the CNS and both potentiated sleeping time induced by
hexobarbitone. However, other investigators did not attribute these effects to
either the flavonoid or alkaloids in passionflower. It is also thought that
maltol and ethylmaltol may mask the CNS stimulant effects of the harman
Expert opinion on the chemical constituents responsible for the sedative
action of passionflower is divided. Even though maltol appears to be a likely
candidate, some researchers have called for further studies confirming the
pharmacological effects of specific active constituents. In addition, clinical
investigations on the effects of passionflower on humans are urgently needed.
|Dosage Ranges and Duration of
- Infusion: 2 to 5 g dried herb tid
- Fluid extract (1:1 in 25% alcohol): 0.5 to 1.0 ml tid
- Tincture (1:5 in 45% alcohol): 0.5 to 2.0 ml tid
No side effects reported. The value for acute toxicity of passionflower fluid
extract (I.P.) was greater than 900 mg/kg in mice. Toxic cyanogenic glycosides
have been isolated from related Passiflora species, but not for
Although passionflower extracts and preparation are generally devoid of
contraindications, only limited toxicity data are available. Excessive oral
intake may induce sedative effects and potentiate existing MAOI therapy. For
this reason, passionflower should not be consumed in quantities higher than
recommended doses. This herb should be completely avoided during pregnancy and
lactation since harman and harmaline have been shown to have in vivo
uterine-stimulant action in some studies.
Oral administration of an aqueous extract of passiflora incarnata (160 mg/kg)
following intraperitoneal dosing with pentobarbital (50 mg/kg) significantly
prolonged the sleeping time induced by the pentobarbital in rats (Speroni and
|Regulatory and Compendial
In 1978, the U.S. FDA banned passionflower as an ingredient in OTC sedative
preparations. In Britain, passionflower is on the General Sale List (GSL), and
in Germany, it is authorized by Commission E for use in remedies. The Council of
Europe approves passionflower as a natural source of food flavoring (category
N3) that can be added to foodstuffs. However, the Council also notes that the
potential toxicity of passionflower cannot be fully assessed because current
information is insufficient.
Aoyagi N, Kimura R, Murata T. Studies on Passiflora incarnata dry
extract. I. Isolation of maltol and pharmacological action of maltol and ethyl
maltol. Chem Pharm Bull. 1974;22:1008-1013.
Blumenthal M, ed. The Complete German Commission E Monographs. Boston,
Mass: Integrative Medicine Communications; 1998: 179-180.
Dorland's Illustrated Medical Dictionary. 25th ed. Philadelphia, Pa:
WB Saunders; 1974.
Grieve M. A Modern Herbal. Vol. II. New York, NY: Dover;
Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines.
Montvale, NJ: Medical Economics Company; 1998:1015-1016.
Kimura R, et al. Central depressant effects of maltol analogs in mice.
Chem Pharm Bull. 1980;28:2570-2579.
Mabberley DJ. The Plant-Book: A Portable Dictionary of the Higher
Plants. England: Cambridge University Press; 1987:434.
Minghetti A. Neuropharmacological activity of extracts from Passiflora
incarnata. Planta Med. 1988;54:488-91.
Newall C, Anderson L, Phillipson J. Herbal Medicines: A Guide for
Health-care Professionals. London, England: Pharmaceutical Press; 1996:
Nicholls JM, et al. Passicol, an antibacterial and antifungal agent produced
by Passiflora plant species: qualitative and quantitative range of
activity. Antimicrob Agents Chemother. 1973;3:110-117.
Soulimani R, Younos C, Jarmouni S, Bousta D, Misslin R, Mortier F.
Behavioural effects of Passiflora incarnata L. and its indole alkaloid
and flavonoid derivatives and maltol in the mouse. J Ethnopharmacol.
Speroni E, Minghetti A. Neuropharmacological activity of extracts from
Passiflora incarnata. Planta Medica. 1988;54:488-491.
Tyler V. Herbs of Choice: The Therapeutic Use of
Phytomedicinals. Binghamton, NY: Pharmaceutical Products Press; 1994:119.
Tyler V. The Honest Herbal: A Sensible Guide to the Use of Herbs and
Related Remedies. 3rd ed. New York, NY: Pharmaceutical Products Press;
Copyright © 2000 Integrative Medicine
CommunicationsThis publication contains
information relating to general principles
of medical care that should not in any event be construed as specific
instructions for individual patients. The publisher does not accept any
responsibility for the accuracy of the information or the consequences arising
from the application, use, or misuse of any of the information contained herein,
including any injury and/or damage to any person or property as a matter of
product liability, negligence, or otherwise. No warranty, expressed or implied,
is made in regard to the contents of this material. No claims or endorsements
are made for any drugs or compounds currently marketed or in investigative use.
The reader is advised to check product information (including package inserts)
for changes and new information regarding dosage, precautions, warnings,
interactions, and contraindications before administering any drug, herb, or
supplement discussed herein.