There exists a host of plant compounds that are being studied for their properties to aid in these mental and emotional disturbances. In the plant, there is usually one predominant active ingredient, however, there can also be an abundance of ingredients creating what is presumed to be a synergistic effect. For example, valerian has over 150 of these active ingredients. Originally developed in plants as a means of defense, these compounds are generally recognized as safe however there are some that may be toxic in large doses, such as kava kava or Saint John's Wort (not my favorite, by the way!).
In vitro or lab studies are used to determine the mechanism of action, or pharmacological properties of these extracts or compounds, while clinical trials are used to determine the actual effectiveness in humans. These trials may or may not be conducted in a suitable way to determine the appropriate efficacy or guidelines for recommendations, however with greater number of trials, the likelihood that a systematic review or meta-analysis with the highest quality of evidence may be used to determine the efficacy based on the pooled data of replicable studies. These types of studies are not as common in complimentary or integrative medicine, however, they are indeed increasing and with some good results. Plant extracts are pharmacologically more relevant and can be standardized, thus increasing the quality of the evidence. However, tincture form or plant form are equally as effective in most circumstances.
Here is a list of the most commonly suggested and commercially available products with the basic mechanism of action:
Passionflower (Passiflora incarnata) : Interacts with opioid and GABA-benzodiazepine receptors
Skullcap (Scutellaria lateriflora): Binds to GABA-benzodiazepine receptors; contains GABA
Lemonbalm (Melissa officininalis): Inhibits GABA transaminase (the degradation)
Valerian (Valeriana officinalis): increases GABA release and inhibits GABA breakdown; binds to BDZ receptors
Bacopa (Bacopa monniera): anxiolytic effects not completely understood, enhances mental activity and memory, modulates neurotransmitter function
Gotu kola (Centella asiatica): Stimulates conversion of glutamic acid to GABA
Rhodiola rosea: Inhibits enzymatic breakdown of serotonin, dopamine, and norepinephrine, communication between innate and adaptive immune system, cAMP mediated pathways in heart cells,
Hops (Humulus lupulus): stimulated GABA production, inhibits central nervous sytem
Kava kava (Piper methysticum) : Binds to GABA receptors; inhibits norepinephrine uptake
Safran (Crocus sativa): Inhibits reuptake of serotonin, dopamine, and norepinephrine
Lavender (Lavendula spp.): mechanism unknown, anti-depressant and anxyolitic
This is but a basic description of the properties found in these plants and there are also other well studied plants to consider such as Withania somnifera, Eleutherococcus senticosus, Panax ginseng, Panax notoginseng, Nepeta menthanoides, Ginkgo biloba, Aveena sativa, among others such as turmeric and ginger. A full scientific appraisal is beyond the scope of this blog post however I would be happy to discuss the clinical trials if that is of interest, especially for efficacy, side effects, dosages, and duration.
FUN FACT! Did you know that safran is a native plant to Montreal and is the first flower to bloom in the spring! You will usually find it blooming on its own close to a home :)
Disclaimer: this post is not intended to diagnosis or treat a medical condition, please see your health care provider if you suspect you may benefit from plants and their extracts.
Sarris J. 2018. Herbal medicines in the treatment of psychiatric disorders: 10-year updated review. Phytoter. Res. 32(7):1147-1162.
Panossian A et al. 2014. Mechanism of action of Rhodiola, salidroside, tyrosol and triandrin in isolated neuroglial cells: an interactive pathway analysis of the downstream effects using RNA microarray data. Phytomedicine. 21(11):1325-48
Franco et al. 2012. The sedative effects of hops (Humulus lupulus), a component of beer, on the activity/rest rhythm. Acta Physiol Hung. 99(2): 133-9.
Head KA and Kelly GS. 2009. Nutrients and botanicals for treatment of stress: adrenal fatigue, neurotransmitter imbalance, anxiety, and restless sleep. Altern Med Rev. 14(2):114-40.