Herbal Nerd Society Exclusive Article
Passionflower (Passiflora incarnata) is an herb commonly used for its anxiolytic (anxiety/panic reducing) effects. This native North American vine has many other medicinal uses such as wound care due to its astringent qualities. Although this article focuses on Passiflora incarnata, there are close to 550 other passiflora species and a handful, such as Passiflora edulis, are studied as well. Its most common use is due to it calming effect on the nervous system. There is much research yet to be done on the constituents of passionflower but the recent studies are very promising.
There are a variety of chemical compounds in passionflower that have commanded the attention of biochemists. Harmoline, maltol, 2-phenylethanol, chrysin, vitexin, coumerin, and umbelliferone are among the key players in this herb’s list of anxiolytic agents. There is speculation that even as each of these compounds has a steadying effect on the nervous system, it is the fact that they work in slightly different ways that lends most dramatically to it’s medicinal value as an anxiety reducer.
Passionflower has been used consistently in much of Europe as a sedative. The United States used to sell it as an over-the-counter (OTC) sedative in pharmacies until 1978 when the FDA relegated it to Category II list siting lack of evidence for efficacy. Although it is taken as single plant remedy, it is most often ingested as part of a formula. It is important to note that as more information about the constituents (ie. chrysin) listed above are revealed, the odds that passionflower will reappear on the FDA’s list of approved OTC herbs increases.
Of all the constituents being studied, chrysin commands the most attention thus far. This bioflavonoid was being examined for possible neurotoxicity and instead was discovered to be neuroprotective. As a anxiolytic treatment, chrysin is noted for its ability to reduce inflammation of the nerves which is considered one of the primary ways to reduce symptoms of Generalized Anxiety Disorders (GADs).
Passionflower’s collection of bioflavonoids bind to benzodiazepine receptors sites and acts as an agonist for gamma-aminobutyric acid (GABA) activity. Simply put, our nervous systems have channels that open and close to allow the passage of ions into the neuron. An estimated 40% of them are GABA receptors. When these receptors bind to GABA, it changes shape and opens its channel so that negatively charged chloride ions can pass through this portal thus reducing agitation (anxiety) in the neuron. Other chemicals like benzodiazepine and the bioflavonoids in passionflower also bind to the GABA receptor. This is how passionflower earns its title as an anxiolytic agent.
Counter-Indications for Passionflower
Passionflower, as mentioned above, is primarily used to as a sedative to promote sleep and reduce anxiety. Taking passionflower along with sedative medications might cause too much sleepiness. Do not take passionflower if you are pregnant or breast feeding without first consulting with a qualified healthcare practitioner.
Further Research
NCBI – Neuroprotective Effects of Chrysin: From Chemistry to Medicine
NCBI – GABA Receptor Physiology and Pharmacology
