PASSION FLOWER

BACKGROUND

Ingredient Type: Botanical, Extract

Also Known As: Passiflora incarnata L., Passionflower, Maypop, Apricot vine, Maracuja, Water lemon

Passiflora incarnate L., also known as passionflower, is a species of plant found in Brazil, the tropical Americas, Asia, and Australia.  Its fruits and flowers contain several compounds such as tannins, coumarin alkaloids, flavonoids, tyrosine, and glycine.

The passionflower received its name when Christian missionaries arrived in South America during the 16th century.  The early missionaries found a plant which they felt was a good omen for their mission.  They decided to call it the passionflower because it was symbolic of the death of Christ to them (1).

TRADITIONAL USES

Native American tribes, such as the Cherokee, used purple passionflower for food, drink, and for medicinal purposes. In 1612, Captain John Smith stated that Native Americans ate the fruits either raw or boiled to make syrup. A drink was prepared by straining the juice from the fruit.  The roots were used to make an infusion for boils and to “draw out inflammation” of wounds.  Native Americans also made a tea from the roots to help babies in weaning. Different parts of the plant were also used to treat earaches, liver problems, and as a sedative to treat nervous conditions and hysteria (2).

WHAT DOES SCIENCE TELL US?

Passionflower Probably Helps with Relaxation:

A few studies looked at the effectiveness of passionflower in treating anxiety caused by an upcoming medical procedure, such as dental extraction or surgery.  In one study, passiflora and midazolam were compared for treating anxiety for patients undergoing dental extraction.  40 volunteers underwent bilateral extraction of their mandibular third molars and were given 260mg of Passiflora incarnata or midazolam 30 minutes before surgery.  The results of the study showed that passionflower had an anxiolytic effect comparable to midazolam and was safe and effective for conscious sedation for patients undergoing dental extraction (3).

In a randomized, one-sided, blind clinical trial, the effect of passionflower in reducing anxiety before dental procedures in patients with moderate, high and severe anxiety was assessed.  The study found that passionflower was significantly effective in anxiety reduction.  63 patients were divided into 3 groups of 21 in which one group was given passionflower, another was given a placebo, and a third group was given neither placebo nor passionflower.  The results showed a significant reduction in anxiety level for the passionflower group (12.09±2.42 compared to 8.47± 2.58; p-value <0.0001) indicating that administering passionflower as a premedication could be very effective in reducing anxiety (4).

A third study examined the effect of passionflower on anxiety, psychomotor function, sedation, and hemodynamics in patients about to undergo spinal anesthesia.  30 minutes before spinal anesthesia, baseline hemodynamic parameters, State-Trait Anxiety Inventory score, sedation score, and psychomotor function tests were performed.  60 patients aged 25-55 who were scheduled for spinal anesthesia were given either passionflower extract or placebo.  The tests were repeated just before spinal anesthesia was given. The results found that anxiety was reduced before spinal anesthesia without changes in psychomotor function, sedation level or hemodynamics (5).

Another study also looked at the effect of passionflower on anxiety before surgery.  In this study, 60 patients received either oral Passiflora incarnata (500 mg, Passipy IranDarouk) or placebo as premedication 90 minutes before surgery.  Anxiety and sedation were assessed using a numerical rating scale (NRS) 10, 30, 60, and 90 minutes after premedication.  The results showed that the NRS anxiety scores were noticeably lower in the passionflower group than in the placebo group (p<0.001).  The results also showed that there were no significant differences in psychological variables and recovery of psychomotor function was similar in the two groups (6).

Another trial was done to compare the effect of administrating melatonin and passion flower before surgery on the postoperative cognitive disorders of adult patients who were undergoing elective surgery.  52 patients received either 1000mg of Passiflora incarnata or 6mg melatonin as a premedication one hour before surgery.  Pain after surgery was assessed using the visual analog scale (VAS) while anxiety and cognitive dysfunction were analyzed using the Ramsey score and digital substitution test (DSST) respectively.  The results found that there was no statistically significant VAS between the two groups (p>0.05) but the average pain score was higher among the melatonin group than the passiflora group.  In general, they found that passionflower is as effective for reducing anxiety as well as melatonin, but melatonin causes less cognitive impairment (7).

Besides treating anxiety before surgery, a literature review was done that examines the effectiveness of passiflora in treating any anxiety disorder.  For the review, only two studies with a total of 198 participants were eligible for inclusion.  They found that for one study, it was indicated that there was a lack of difference in the efficacy of benzodiazepines compared to passiflora.  They also found that even though the results of one study showed that job performance was improved with passiflora and the other showed a lower rate of drowsiness compared to mexazolam, neither of these results had statistical significance.  The author concluded that random control trials (RCTs) that examine the effectiveness of passiflora for anxiety are too few to allow conclusions to be drawn and suggests that there is a need for more studies with larger samples that compare passiflora to other types of medication including antidepressants (8).

Another study supports that passionflower can be used for treating generalized anxiety disorder.  A double-blind, randomized trial compared the effectiveness of passionflower extract with oxazepam for the treatment of generalized anxiety disorder (GAD).  36 out-patients diagnosed with GAD were divided randomly into two groups of 18.  One group was designated as the passiflora extract 45 drops per day plus placebo tablet group and the other was the oxazepam 30 mg/day plus placebo drops group.  The trial was done for 4 weeks and found that passionflower was effective in reducing anxiety with a lower incidence of impairment of job performance (9).

Passionflower Possibly Improves Sleep Quality:

Studies show promise that passionflower could be used as a sleep aid.  One study was done to assess the effectiveness of passion flower as a sleep aid to reduce sleep disturbances.  41 participants were given either passionflower or a placebo tea.  The results showed that a low dose consumption of passionflower tea resulted in sleep benefits for adults whose sleep quality mildly fluctuated (p<0.01) (10).

A randomized controlled trial was done to assess the effectiveness and safety of NSF-3, a polyherbal sedative-hypnotic formulation that contained passionflower along with Valeriana officialis and Humulus lupulus as a treatment for primary insomnia as compared to zolpidem.  91 persons were recruited and 39 persons in each group finished the study.  They were either given one tablet of NSF-3 or 10mg of zolpidem at bedtime for two weeks.  The results showed improvement in total sleep quality in both groups but there was no statistical difference found between the two groups.  They found that the formulation was a safe, short-term alternative but more research needs to be done to assess long-term benefits and safety (11).

Passionflower Possibly Aid with Drug Withdrawal Symptoms:

A double-blind, randomized control trial was done to assess the management of withdrawal symptoms.  65 opiate addicts were assigned randomly to different groups to be treated either with passiflora extract plus clonidine tablet or clonidine tablet plus placebo drop in a 14-day trial.  The results showed that both were equally effective for treating withdrawal symptoms but the passiflora plus clonidine group was superior for managing mental symptoms.  More research with larger studies would need to be done to confirm these findings (12).

Passionflower Possibly Helps Support Concentration in Children and Adolescents:

A study was done to assess the effect of passionflower on ADHD among children and adolescents.  34 children with ADHD received either 0.04 mg/kg/day passionflower or 1 mg/kg/day methylphenidate twice daily for 8 weeks.  The results showed that there were no significant differences between the two groups on the Parent and Teacher Rating Scale score during the trial and both groups benefitted greatly based on the assessment by both teachers and parents.  Decreased appetite and anxiety/nervousness was also observed more in the methylphenidate group than in the passionflower group (13).

SAFETY

Interactions:

Major

• Since it has calming effects, passionflower may increase the effects of sedative medication (14).  A case study looked at a patient who self-medicated with both Valeriana officinalis L. and Passiflora incarnata L. while taking prescribed lorazepam (15).  He was reported to have handshaking, dizziness, throbbing, and muscular fatigue 32 hours before clinical diagnosis.  The active principles of both Valeriana officinalis L. and Passiflora incarnata L. may increase the inhibitory action of benzodiazepines, which bind to the GABA receptors and may result in severe secondary effects (15).
• Passionflower may also increase the amount of time it takes for blood to clot.  When used with anticoagulants and antiplatelets, it could increase the risk of bleeding (14).  It may also interact with Monamine oxidase inhibitors, an older class of antidepressants, by increasing their effects and their side effects which may potentially be dangerous (14).

Moderate

• Passionflower may interact with other herbal supplements.  A study reported that passionflower significantly enhances the anti-depressive therapeutic effects of St. John’s Wort (Hypericum perforatum) compared to when it is used alone (16).

Side-Effects:

• One case study reported that a woman had severe nausea, vomiting, drowsiness, prolonged QTc intervals (heart rate intervals), and episodes of non-sustained ventricular tachycardia after self-medicating with passionflower (17).
• Another article reported five pregnant women with depression and/or anxiety who self-medicated with passiflora during pregnancy.  Among those five women, one pregnancy resulted in neonatal death, two had premature rupture of membranes, two infants had meconium aspiration syndrome, and one infant had persistent pulmonary hypertension.  There is a lack of data on the effects of passionflower during pregnancy, so pregnant women exposed to Passiflora incarnata should be monitored (18).

REFERENCES

1. Passion Flower. http://plantsinmotion.bio.indiana.edu/plantmotion/flowers/passionflower/passion.html. Accessed June 22, 2018.
2. “Purple Passionflower.” Plant Guide, plants.usda.gov/plantguide/pdf/cs_pain6.pdf. Accessed June 7, 2018.
3. Dantas L-P, de Oliveira-Ribeiro A, de Almeida-Souza L-M, Groppo F-C. Effects of passiflora incarnata and midazolam for control of anxiety in patients undergoing dental extraction. Med Oral Patol Oral Cir Bucal. 2017;22(1):e95-e101.
4. Kaviani N, Tavakoli M, Tabanmehr M, Havaei R. The efficacy of passiflora incarnata linnaeus in reducing dental anxiety in patients undergoing periodontal treatment. J Dent (Shiraz, Iran). 2013;14(2):68-72.
5. Aslanargun P, Cuvas O, Dikmen B, Aslan E, Yuksel MU. Passiflora incarnata Linneaus as an anxiolytic before spinal anesthesia. J Anesth. 2012;26(1):39-44. doi:10.1007/s00540-011-1265-6
6. Movafegh A, Alizadeh R, Hajimohamadi F, Esfehani F, Nejatfar M. Preoperative Oral Passiflora Incarnata Reduces Anxiety in Ambulatory Surgery Patients: A Double-Blind, Placebo-Controlled Study. Anesth Analg. 2008;106(6):1728-1732. doi:10.1213/ane.0b013e318172c3f9
7. Rokhtabnak F, Ghodraty MR, Kholdebarin A, et al. Comparing the Effect of Preoperative Administration of Melatonin andPassiflora incarnataon Postoperative Cognitive Disorders in Adult Patients Undergoing Elective Surgery. Anesthesiol pain Med. 2017;7(1):e41238. doi:10.5812/aapm.41238
8. Miyasaka LS, Atallah ÁN, Soares B. Passiflora for anxiety disorder. Cochrane Database Syst Rev. 2007;(1):CD004518. doi:10.1002/14651858.CD004518.pub2
9. Akhondzadeh S, Naghavi HR, Vazirian M, Shayeganpour A, Rashidi H, Khani M. Passionflower in the treatment of generalized anxiety: a pilot double-blind randomized controlled trial with oxazepam. J Clin Pharm Ther. 2001;26(5):363-367.
10. Ngan A, Conduit R. A Double-blind, Placebo-controlled Investigation of the Effects of Passiflora incarnata (Passionflower) Herbal Tea on Subjective Sleep Quality. Phyther Res. 2011;25(8):1153-1159. doi:10.1002/ptr.3400
11. Maroo N, Hazra A, Das T. Efficacy and safety of a polyherbal sedative-hypnotic formulation NSF-3 in primary insomnia in comparison to zolpidem: A randomized controlled trial. Indian J Pharmacol. 2013;45(1):34. doi:10.4103/0253-7613.106432
12. Akhondzadeh S, Kashani L, Mobaseri M, Hosseini SH, Nikzad S, Khani M. Passionflower in the treatment of opiates withdrawal: a double-blind randomized controlled trial. J Clin Pharm Ther. 2001;26(5):369-373.
13. Akhondzadeh S, Mohammadi MR, Momeni F. Passiflora incarnata in the treatment of attention-deficit hyperactivity disorder in children and adolescents. Therapy. 2005;2(4):609-614. doi:10.1586/14750708.2.4.609
14. School UOMMC. Passionflower | University of Maryland Medical Center. https://www.umm.edu/health/medical/altmed/herb/passionflower. Accessed March 8, 2018.
15. Carrasco MC, Vallejo JR, Pardo-de-Santayana M, Peral D, Martín MÃ, Altimiras J. Interactions of Valeriana officinalis L. and Passiflora incarnata L. in a patient treated with lorazepam. Phyther Res. 2009;23(12):1795-1796. doi:10.1002/ptr.2847
16. Fiebich BL, Knörle R, Appel K, Kammler T, Weiss G. Pharmacological studies in an herbal drug combination of St. John’s Wort (Hypericum perforatum) and passion flower (Passiflora incarnata): In vitro and in vivo evidence of synergy between Hypericum and Passiflora in antidepressant pharmacological models. Fitoterapia. 2011;82(3):474-480. doi:10.1016/j.fitote.2010.12.006
17. Fisher AA, Purcell P, Le Couteur DG. Toxicity of Passiflora incarnata L. J Toxicol Clin Toxicol. 2000;38(1):63-66.
18. Ozturk Z, Kalayci CC. Pregnancy outcomes in psychiatric patients treated with passiflora incarnata. Complement Ther Med. 2018;36:30-32. doi:10.1016/j.ctim.2017.11.008

See the European Medicines Agency public summary for Passiflorae herba, the National Center for Complementary and Integrative Health entry for passionflower, the Penn State Hershey Health Information Library entry for passionflower, the Michigan Medicine Health Library entry for passion flower, or the RXList entry for passion flower for more information.