When European settlers first encountered a passion flower, it is arguable that, stunned by so much beauty, they had neither the time nor the inclination to inquire about its healing properties . We know, for example, that the Algonquin tribe granted passionflower the role of tranquilizer in their pharmacopoeia . Other Native Americans used the plant to soothe puffy, irritated eyes, and the root as a general tonic. Long before that, this passion flower was grown in gardens during the time of the great Aztec rulers such as Moctezuma .
A little history
Although introduced to Europe in the 17th century, passionflower is not regarded as anything other than ornamental; we are therefore not surprised that its therapeutic history is relatively recent on the old continent; especially since it was not until 1867 that the sedative action of passionflower was mentioned for the first time by an American doctor named Phares , corroborated by Stapleton in 1904. These pharmacodynamic discoveries therefore have nothing to do with European, although they were imported from North America to Europe, where passionflower was very early welcomed.
What are the main pharmacological properties of the aerial parts of Passiflora?
Passionflower has hypnotic, anxiolytic, anticonvulsant and analgesic activities , in relation to the concomitant and synergistic action of all the components of the plant. These properties, demonstrated in vivo , are indeed beginning to be demonstrated in humans; as shown in a 2001 pilot double-blind randomized controlled trial conducted in 36 patients for 4 weeks, indicating anxiolytic activity of passionflower equivalent to that of oxazepam .
Another double-blind, placebo-controlled study in 2009 notably showed that taking 500 mg of Passiflora incarnata extract 90 minutes before surgery effectively reduces preoperative stress, which is confirmed by another trial carried out in 2012 before spinal anesthesia with of 60 patients aged 25 to 55, a result obtained without changing the parameters of the psychomotor function tests, the level of sedation or the haemodynamic data.
Plant activity is mediated by monoamine oxidase inhibition; stimulation of serotonin production as well as an agonist effect at the y-aminobutyric acid (GABA) receptors. This activity on the gabaergic system would be partly linked to its harmane-type indole alkaloids and its flavonoids (chrysin, homo-orientin, vitexin, isovitexin). These compounds would contribute to the anxiolytic activity of the plant, comparable in vivo to that of diazepam . Extracts of Passiflora incarnata induce GABA currents in hippocampal neurons in vitro , and exhibit anticonvulsant effectsin vivo , variable according to the method of extraction. This activity involves gabaergic benzodiazepine and opioid receptors.
Passiflora incarnata thus improves spatial memory in a dose-dependent manner and reduces anxiety . It actually influences neurotransmission, by reducing the glutamic acid content of the hippocampus and cortical serotonin. It also increases the levels of metabolites and their turnover, which partially confirms the mechanism of action of the plant on GABA receptors.
After an increase in the subject’s motility and exploratory activity during the first 3 hours after taking passionflower, there is then a marked slowing down of general activity with a sedative then hypnotic component , increasing the duration of the sleep and potentiating the effect of sleeping pills. In addition, passionflower lowers body temperature, a favorable condition for entering sleep. This effect is therefore reinforced by the anticonvulsant and antispasmodic action of maltol, present in small quantities in the plant. In vitro and in vivo, passionflower extract positively modulates circadian rhythms by inducing large amplitude rhythms without phase shift in the expression of several genes of the circadian clock.
A double-blind, placebo-controlled study conducted in 2012 in 41 healthy volunteers (18 to 35 years old) followed by polysomnography also evaluated the effects of administration for 7 days of an aqueous extract of Passiflora incarnata on the amount of sleep. It showed significant positive correlations between subjective measures and quantitative polysomnographic measures of sleep (sleepiness and efficiency) compared to placebo.
A 2017 in vivo study showed that P. incarnata significantly increases total sleep time , in relation to an increase in the time subjects spend in slow wave sleep, and a significant decrease in wakefulness. On the other hand, the time spent in REM sleep showed a downward trend, with a reduction in its frequency and its average duration.
In vivo , other anti-nociceptive and behavioral (sedation, anxiolysis) results obtained with P. incarnata confirm that its activity may derive from underlying opioid and gabaergic mechanisms, and could also imply potential cannabimimetic-like action. This work indeed shows that the plant could be useful for treating neuropathic pain .
In vivo , in an animal model of sleep disorders, it was confirmed, in 2019, that vitexin, the main bioactive component of the ethanolic extracts of leaves and fruits of Passiflora incarnata , further improves hyppocampal neurogenesis, with evidence of d an increase in brain-derived neurotrophic factor (BDNF) in the hippocampus and a significant decrease in Tau protein (a marker of Alzheimer’s disease ) compared to the control group. These benefits are complemented by a improved memoryaccording to the water maze test, all without any change in the feeding behavior, body weight, metabolic level and body composition of the animals. These results identify passionflower as a potential therapy to improve memory functions, and prevent Alzheimer’s disease , by acting on the hippocampus.
In 2019, a qualitative, exploratory and observational study conducted in Switzerland analyzed for the first time the experiences of patients, in relation to the use of an ethanolic extract of Passiflora incarnata . The authors identified three distinct types of patient biographical accounts attributed to different experiences while using the herb. In Type 1 stories, users described moving from a performance-oriented focus to calm reprioritization. Patients with type 2 narratives maintained a performance orientation while adopting calm, whereas those delivering type 3 narratives maintained a performance orientation, and suffered from persistent illness.
The trisubstituted benzoflavone (BZF fraction) from passionflower has shown significantly encouraging results in reversing the tolerance and dependence of several addiction-prone psychotropic drugs, including morphine, nicotine, ethanol, diazepam and delta-9- tetrahydrocannabinol .
Aids in benzodiazepine withdrawal: Not only does the BSF fraction of passionflower not produce addiction on its own, but it attenuates dependence on benzodiazepines, as has been shown in vivo .
Assistance with alcohol withdrawal: In vivo , a 2017 study notably showed that alcohol-treated groups showed increased nociceptive thresholds after alcohol withdrawal, which was reversed by Passiflora incarnata , when measurement by the hot plate test. In addition; alcoholism treatment increased levels of brain-derived neurotrophic factor (BDNF) and interleukin-10 in the prefrontal cortex, which P. incarnata did not reverse. These results indicate that the plant could be a potential treatment for alcohol withdrawal syndrome.
The peripheral activity of passionflower also contributes to relaxation and the induction of restful sleep.
Passionflower is a muscle antispasmodic. It induces an increase in the amplitude of the contractions, a decrease in their frequency as well as a drop in general tone. Moreover, it potentiates the effects of papaverine, and antagonizes pilocarpine.
On the cardiovascular system:
Passionflower also has a calming action on the heart .
On the respiratory system:
An increase in respiratory amplitude and frequency is therefore observed . In a placebo-controlled study conducted for 4 weeks; administration of passionflower bark extract significantly reduced asthmatic symptoms.
Are there any precautions for use concerning Passionflower?
- According to the EMA; the use of passionflower is not recommended for pregnant or breastfeeding women and for children under 12, because of the presence of alkaloids .
Precautions for use:
- Like any sedative plant, depending on the dosage and the sensitivity of the person; passionflower could cause a decrease in alertness, and be dangerous when using machines or driving vehicles.
- The advice of a doctor or health care professional is therefore advised if used under 12 years of age or if symptoms worsen while using passionflower.
Drugs interactions :
- Passionflower could increase the sedative effect of plants and synthetic drugs such as anxiolytics or antidepressants, as well as the activity of anticoagulants. Medical advice is advised in case of association.
- Possible pharmacological interactions with benzodiazepines (lorazepam).
- Passionflower extracts containing the flavonoids orientin, apigenin, vitexin, could interact with organic anion transport polypeptides OATP2B1 and OATP1A2 and thus affect the absorption of certain hormones (estrone-3, pregnenolone, dehydroepiandrosterone sulfates) .
How to take Passionflower and at what dosage?
- As a dietary supplement, in the form of extract standardized fresh plant , of solids , of powder , in capsules.
- Standardized fresh plant fluid extract : 5 to 10 ml per dose in water.
- Integral suspension of fresh plant : 5 to 10 ml 1 to 3 times / day in water.
- Honeyed glycerine fluid extract : 5 ml 2 to 3 times a day in water.
- Mother tincture : 20 to 30 drops 1 to 3 times a day in water or an infusion.
- Infusion : 1 to 2 teaspoons of drug for 150 ml for 10 min, 1 cup 1 to 3 times a day.
Medical bibliographic sources and clinical trials :
Lutomski J. et al., The importance of the passionflower in medicine, Pharm Unserer Zeit., 1981
Grundmann O. et al. Anxiolytic activity of a phytochemically characterized Passiflora in car nata extract is mediated via the GABAergic system ; Planta Med., 2008
Dhawan K. et al., Anxiolytic activity of aerial and underground parts of Passiflora incarnate, Fitoterapia, 2001
Dhawan K. et al., Passiflora : a review update, J Ethnopharmacol., 2004
Miyasaka L.S. et al., Passiflora for anxiety disorder, Cochrane Database of Systematic Reviews, 2007
Guerrero F.A. et al. Effect of a medicinal plant (Passiflora in car nata L) on sleep, Sleep science (Sao Paulo, Brazil), 2017
Toda K. et al. Passionflower Extract Induces High-amplitude Rythms; without Phase Shifts in the Expression of Sevral Circadian Clock Genes in vitro and in vivo; Int J Biomed Sci., 2017
Aman U. et al., Passiflora incarnata attenuation of neuropathic allodynia and vulvodynia apropos GABA-ergic and opioodergic antinociceptive and behavioural mechanisms; BMC complementary and alternative medicine, 2016
Elsas S.M. et al., Passiflora incarnata L. (Passionflower) extracts elicit GABA currents in hippocampal neurons in vitro; and show anxiogenic and anticonvulsivant effects in vivo, varying with extraction method; Phytomedicine, 2010
Miroddi M. et al. Passiflora in car nata L.: ethnopharmacology, clinical application, safety and evaluation of clinical trials, J Ethnopharmacol., 2013
Appel K. et al., Modulation of the y-aminobutyric acid (GABA) system by Passiflora incarnata L., Phytother Res., 2011
Paladini A.C. et al., Flaconoids and the central nervous system: from forgotten factors ti potent anxiolytic comprounds, J Pharmacol., 1999
Akhondzadeh S., Naghavi H.R., Vazirian M. et al., Passion flower in the treatment of generalized anxiety; A pilot double-blind randomized controlled trial with oxazepam, J Clin Pharm Ther, 2001
Dhawan K., Drug/substance reversal effects of a novel trisbstituted benzoflavone moiety (BZF) isolated from Passiflora in car nata Linn. A brief perspective, Addict Biol., 2003
Movafegh A. et al., Preoperative oral Passiflora incarnata reduces anxiety in ambulatory surgery patients: a double-blind, placebo-controlled study; Anesth Analg., 2008
Watson R.R. et al. Nutr Oral administration of the purple passion fruit peel extract reduces wheeze car. And cough and improves shortness of breath in adults with asthma; Res., 2008
Canalla C. et al., Patients’ experiences attributed to the use of Passiflora incarnata: A qulitative phenomenological study, J Ethnopharmacol., 2019
Aslanagun P. et al., Pssiflora incarnata Linneaus as an anxiolytic before spinal anesthesia, J Anesth., 2012
Ngan A. et al. A double-blind, placebo-controlled investigation of the effects of Passiflora in car nata (passionflower) herbal tea on subjective sleep quality; Phytother Res., 2011