Ingredient spotlight: Passionflower

Every herbalist has their favourite herbs - herbs they turn to every day for specific types of patients, herbs they have a personal relationship with, or just herbs that are generally awesome.

Passionflower (Passiflora incarnata) is a herb I have a lot of time for. Aside from its sleep inducing properties, there are so many other uses for this enchanting plant that make it invaluable in clinical practice.

We’ll talk about the many uses of passionflower, along with its chemistry and some evidence for how it works - but first, let’s start with some background.  

A passionate history

Passionflower is native to North and South America, and was first brought to Europe from Peru by the Spanish conquistadors.

They had learnt from the Aztecs that the plant was used as a sedative for nervousness and insomnia - it was introduced into European medicine and cultivated widely.

They named it ‘flor de la passion’ due to some imagined religious symbolism in the flower which they said represented the crucifixion of Jesus Christ - the end of the period of his life known as The Passion.

The intricate beauty of passionflower speaks to modern herbalists in an entirely different way, of course, and this is much more to do with its interesting chemical make-up and powerful medicinal actions.

What's in a plant?

Looking at the plant, it’s no wonder that passionflower contains hallucinogenic compounds. These are known as ‘indole alkaloids’, though commercial preparations will have fewer of these constituents.

Harmine, an indole alkaloid originally known as ‘telepathine’ (1), induces a contemplative state and mild euphoria, presumed to work through serotonin receptors.

Researchers have differed on whether passionflower’s sedative effects are due to the indole alkaloids or its rich flavonoid content, including apigenin, scopoletin and chrysin, which has been shown to bind to benzodiazepene receptors (2).

Passiflora is also said to contain more of the calming neurotransmitter gamma-amino butyric acid (GABA) than 20 other plants examined (3).

Passionflower in action 

I think of a ‘passionflower person’ as someone who is ‘wound up’, tense and anxious - who finds it difficult to calm down enough to get a good, nourishing sleep.

Several clinical studies have confirmed this calming effect on the nervous system. In a randomised controlled trial of 36 patients over 4 weeks, it was found to be as effective as oxazepam - an anti-anxiety drug - with fewer side effects (4).

Another trial measured the self-reported improvement in stress resistance and quality of life in 154 adults with nervous restlessness (5). The results of the 12-week study were significant, and associated symptoms such as sleep disturbance, fatigue, nausea and palpitations were all improved.

A study assessing passionflower’s sleepy effects has also shown great results - the consumption of passionflower tea yielded short-term subjective sleep benefits for 41 healthy adults with mild fluctuations in sleep quality, over 7 days (6).

Something for everyone

Children with attention deficit hyperactivity disorder (ADHD) can benefit hugely from this plant, as can some people with high blood pressure or a fast or irregular heart rhythm.

The herb has also shown promising results in the field of opiate addiction, helping to alleviate the psychological symptoms associated with withdrawal.

What an amazing plant, right?

References

1. Djamshidian A, Bernschneider-Reif S, Poewe W, Lees AJ. Banisteriopsis caapi, a Forgotten Potential Therapy for Parkinson's Disease?. Mov Disord Clin Pract. 2015;3(1):19–26.

2. Brown E, Hurd NS, McCall S, Ceremuga TE. Evaluation of the anxiolytic effects of chrysin, a Passiflora incarnata extract, in the laboratory rat. AANA J. 2007 Oct;75(5):333-7.

3. Carratù B, Boniglia C, Giammarioli S, Mosca M and Sanzini E (2008) Free Amino Acids in Botanicals and Botanical Preparations. Journal of Food Science, 73: C323-C328.

4. Akhondzadeh S1, 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 Oct;26(5):363-7.

5. Gibbert J, Kreimendahl F, Lebert J, Rychlik R, Trompetter I: Improvement of Stress Resistance and Quality of Life of Adults with Nervous Restlessness after Treatment with a Passion Flower Dry Extract. Complement Med Res 2017;24:83-89.

6. Ngan A, Conduit R. A double-blind, placebo-controlled investigation of the effects of Passiflora incarnata (passionflower) herbal tea on subjective sleep quality. Phytother Res. 2011 Aug;25(8):1153-9.