CJ, PhD – Brain Blogger http://brainblogger.com Health and Science Blog Covering Brain Topics Wed, 30 May 2018 15:00:03 +0000 en-US hourly 1 https://wordpress.org/?v=4.9.6 Medicinal Plants and the Brain – Ginkgo, Lemon Balm, and Rhodiola http://brainblogger.com/2018/02/21/medicinal-plants-and-the-brain-ginkgo-lemon-balm-and-rhodiola/ http://brainblogger.com/2018/02/21/medicinal-plants-and-the-brain-ginkgo-lemon-balm-and-rhodiola/#respond Wed, 21 Feb 2018 13:00:02 +0000 http://brainblogger.com/?p=23373 This is the second article in the series on the influence of medicinal plants on the brain. I am describing plants where we have at least one positive double-blind, placebo-controlled trial in humans that supports their medicinal use in brain-related disorders. The last article described St. John’s wort, ashwagandha, and American skullcap, and we can certainly see there is a promising trend towards scientific support for the use of these ancient medicinal herbs.


Ginkgo is a slow growing deciduous tree that grows up to 125-foot-tall and can survive for up to 1000 years. Ginkgo is the oldest surviving tree on Earth as the species dates back to the Jurassic era some 200 million years ago. It has changed remarkably little morphologically since then. It also happens to be one of the best researched medicinal plants with several high-profile publications. A study published in JAMA in 1997 concluded that treatment with ginkgo leaf extract of patients with dementia was safe and capable of improving or stabilizing cognitive performance and social functioning. Another well-controlled study published in 2006 confirmed this result as gingko was found comparable to donepezil in clinical efficacy for dementia treatment. However, a later JAMA study released in 2008 demonstrated ginkgo does not act to prevent dementia occurring in the first place. Ginkgo has also been found effective in the treatment of anxiety, although it is better known as a circulatory stimulant and nootropic (cognitive enhancer). Ginkgo, like the widely used anti-depressant and nervine tonic St. John’s wort, is an example of a medicinal plant success story.

Lemon balm

Lemon balm is another medicinal plant with an ancient history of use by the Romans, ancient Greeks, and Arabs for its medicinal properties. The 11th century Arab physician, Avicenna, wrote, ‘Balm causeth the mind and heart to become merry’. In the middle ages, Europeans used the herb to reduce anxiety and it also became known as something of a cure-all. It is unclear how well founded their belief in lemon balm was as in modern times it is mainly known as an anxiolytic (reduces anxiety), nootropic, anti-depressant, and carminative (reduces excess gas). Double-blind placebo-controlled human studies have shown positive results for lemon balm extracts in the improvement of mood, reduction of anxiety, and improvement of cognitive abilities. These preliminary human trials suggest much of its more recent traditional use is justified.


Rhodiola rosea may have been used as long ago as the Vikings to reduce fatigue and enhance the capacity to work. In an old Icelandic text from 1783, it is described as a herb to enhance the intellect and restore weak nerves. For many centuries Rhodiola was used by folk herbalists in Russia and Scandinavia as a whole-body tonic. There is strong scientific support for the reduction of fatigue with positive results in three well-controlled clinical trials. There is an additional study that found an improvement in mood in the treatment of mild to moderate depression.

Rhodiola is viewed as an adaptogen by modern herbalists, having the dual properties of relaxing and stimulating the nervous system to some degree. Adaptogens can be further grouped depending on how stimulating they are, Rhodiola is more on the stimulating side so should be taken in the morning to avoid insomnia. Ashwagandha, as described in the previous article, is a more calming adaptogen with a greater capacity to support sleep.

Alexander Panossian, the world’s foremost scientific authority on adaptogens, has published a recent review in 2017 describing the mechanism by which adaptogens are thought to work. Our current understanding is they prime the stress response system, namely the sympatho-adrenal or hypothalamic-pituitary-adrenal axes of the endocrine system, in a gentle manner that prepares the body for future stressors or adapting to chronic ones (e.g., major depression). It is thought that the modulation of stress hormones like cortisol and heat shock proteins like HSP70 is central to this mechanism.

A final cautionary note is that adaptogens should not replace good sleep and lifestyle habits. Although they are very mild relative to illegal alternatives, using them inappropriately as stimulants to replace poor sleep habits, in a similar manner to coffee, can eventually lead to burnout. It will be interesting to see how many additional traditional medicinal properties of the adaptogens will be confirmed by modern medical science.


Castleman, Michael. “The new healing herbs.” Bantam Book, New York (2001): 465-471. ISBN: 1605298891

Darbinyan, V., et al. “Clinical trial of Rhodiola rosea L. extract SHR-5 in the treatment of mild to moderate depression.” Nordic journal of psychiatry 61.5 (2007): 343-348. DOI:10.1055/s-2007-986750

Darbinyan, V., et al. “Rhodiola rosea in stress induced fatigue—a double-blind cross-over study of a standardized extract SHR-5 with a repeated low-dose regimen on the mental performance of healthy physicians during night duty.” Phytomedicine 7.5 (2000): 365-371. DOI:10.1016/s0944-7113(00)80055-0

Dastmalchi, Keyvan, et al. “Chemical composition and in vitro antioxidative activity of a lemon balm (Melissa officinalis L.) extract.” LWT-Food Science and Technology 41.3 (2008): 391-400. DOI:10.1016/j.lwt.2007.03.007

DeKosky, Steven T., et al. “Ginkgo biloba for prevention of dementia: a randomized controlled trial.” Jama 300.19 (2008): 2253-2262. DOI:10.1001/jama.2008.683

Kennedy, David O., et al. “Anxiolytic effects of a combination of Melissa ofcinalis and Valeriana ofcinalis during laboratory induced stress.” Phytotherapy research 20.2 (2006): 96-102. DOI:10.1002/ptr.1787

Kennedy, David O., Wendy Little, and Andrew B. Scholey. “Attenuation of laboratory-induced stress in humans after acute administration of Melissa officinalis (Lemon Balm).” Psychosomatic medicine 66.4 (2004): 607-613. DOI:10.1097/01.psy.0000132877.72833.71

Kuhn, Merrily A., and David Winston. Herbal therapy and supplements: a scientific and traditional approach. Lippincott Williams & Wilkins, 2000. ISBN:9781582554624

Le Bars, Pierre L., et al. “A placebo-controlled, double-blind, randomized trial of an extract of Ginkgo biloba for dementia.” Jama 278.16 (1997): 1327-1332. DOI:10.1001/jama.1997.03550160047037

Mazza M., et al. “Ginkgo biloba and donepezil: a comparison in the treatment of Alzheimer’s dementia in a randomized placebo?controlled double?blind study.” European Journal of Neurology 13.9 (2006): 981-985. DOI:10.1111/j.1468-1331.2006.01409.x

Panossian, A., G. Wikman, and J. Sarris. “Rosenroot (Rhodiola rosea): traditional use, chemical composition, pharmacology and clinical efficacy.” Phytomedicine 17.7 (2010): 481-493. DOI:10.1016/j.phymed.2010.02.002

Panossian, Alexander. “Understanding adaptogenic activity: specificity of the pharmacological action of adaptogens and other phytochemicals.” Annals of the New York Academy of Sciences (2017). DOI:10.1111/nyas.13399

Shevtsov, V. A., et al. “A randomized trial of two different doses of a SHR-5 Rhodiola rosea extract versus placebo and control of capacity for mental work.” Phytomedicine 10.2 (2003): 95-105. DOI:10.1078/094471103321659780

Spasov, A. A., et al. “A double-blind, placebo-controlled pilot study of the stimulating and adaptogenic effect of Rhodiola rosea SHR-5 extract on the fatigue of students caused by stress during an examination period with a repeated low-dose regimen.” Phytomedicine 7.2 (2000): 85-89. DOI:10.1016/s0944-7113(00)80078-1

Woelk, H., et al. “Ginkgo biloba special extract EGb 761 in generalized anxiety disorder and adjustment disorder with anxious mood: A randomized, double-blind, placebo-controlled trial.” Journal of psychiatric research 41.6 (2007): 472-480. DOI:10.1016/j.jpsychires.2006.05.004

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Medicinal Plants and the Brain — St. John’s Wort, Skullcap, and Ashwagandha http://brainblogger.com/2017/11/17/the-influence-of-medicinal-plants-on-the-brain-part-i/ http://brainblogger.com/2017/11/17/the-influence-of-medicinal-plants-on-the-brain-part-i/#respond Fri, 17 Nov 2017 16:30:04 +0000 http://brainblogger.com/?p=23131 Medicinal plants still comprise a nebulous cloud in biomedical science. We know they have been used since the dawn of man, but there are precious few good quality scientific studies that support their use. Unlike pharmaceutical drugs, plant medicines consist of many different molecules that interact together in the body to have a variety of, poorly understood, pharmacological effects. Despite variably successful attempts to identify single molecules in plants for drug development, we should acknowledge that the whole is greater than a single part. There is an increasing number of clinical studies which strongly imply that root, leaf, and flower extracts of medicinal plants can influence the brain and are effective at treating cognitive disorders. This article series will examine plants where we have double-blind, placebo-controlled studies to support their medicinal influence on the human brain.

St. John’s wort is a commonly known plant that is native to Europe and yields bright yellow flowers. Its name comes from flowering around St. John’s day on the 24th June. St. John’s wort has been used as long ago as the ancient Greeks, and the physician Dioscorides (40–90AD) used it in the treatment of sciatica. However, St. John’s wort has become known as less of a treatment for nerve pain and more so for depression, with multiple double-blind, placebo-controlled trials confirming its antidepressant properties. Authors typically compare St. John’s wort with mainstream anti-depressant drugs and find it has a preferable side effects profile. It is not without its downsides however, as excessive use has been linked to serotonin syndrome, sun sensitivity, and easy skin burning, and more generally with increased pharmaceutical drug metabolism by the liver. This means St. John’s wort may not be suitable for applications alongside other pharmaceutical drugs, and it is contraindicated with serotonin reuptake inhibitors.

American skullcap is a member of the mint family that is native to North America and grows wild in meadows and swamps. It was used by the Native Americans as a sedative and America’s 19th century physicians, the Eclectics, widely used the herb for complaints involving an overactive nervous system such as insomnia, anxiety, and epilepsy. A human double-blind, placebo-controlled study supports skullcap’s application against anxiety, and a mood elevating effect has also been noted. Herbalist’s view both St. John’s wort and American skullcap as ‘nervine tonics’, meaning that they act upon the nervous system medicinally and are also considered to have a long-term renewing effect. While, this claim is yet to be verified by scientific studies, it certainly warrants further investigation.

Ashwagandha, the root of which is a popular home remedy in India, is a plant native to India that is mentioned in the traditional Ayurvedic medical text, the Charaka Samhita, approximately 2000 years ago. Here it is recommended as a tonic for emancipation, reproductive ability, and longevity. In Ayurveda, it is classified as a ‘rasayana herb’, a class of plant that are considered to restore and support long-term health and that overlaps to some degree with the Western definition of a ‘tonic herb’. Two double-blind, placebo-controlled human studies support ashwagandha’s role in the reduction of anxiety. It’s wide-ranging medicinal properties are supported by two additional well-controlled, human clinical studies on osteoarthritis and subclinical hypothyroidism. The emerging picture is that ashwagandha possesses a wide range of medicinal properties that will likely be better understood in the future. Ashwagandha has been well-tolerated across clinical trials, with a side effect profile similar to placebo.


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Brock C, Whitehouse J, Tewfik I, and Towell T. (2014). American Skullcap (Scutellaria lateriflora): A Randomised, Double-Blind Placebo-Controlled Crossover Study of its Effects on Mood in Healthy Volunteers. Phytotherapy Research, 28(5), 692-698. DOI: 10.1002/ptr.5044

Castleman, Michael. “The new healing herbs.” Bantam Book, New York (2001): 465-471. ISBN: 1605298891

Chandrasekhar K, Kapoor J, and Anishetty S. A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian Journal of Psychological Medicine 34.3 (2012): 255. DOI: 10.4103/0253-7176.106022

Dannawi M. Possible serotonin syndrome after combination of buspirone and St John’s Wort. Journal of Psychopharmacology 16.4 (2002): 401-401. DOI: 10.1177/026988110201600420

Hoffman, David. Holistic herbal. Element Books, 1988. ISBN: 1852300248

Laakmann G, Schüle C, Baghai T, and Kieser M. St. John’s wort in mild to moderate depression: the relevance of hyperforin for the clinical efficacy. Pharmacopsychiatry 31.S 1 (1998): 54-59. DOI: 10.1055/s-2007-979346

Markowitz JS, Donovan JL, DeVane CL, Taylor RM, Ruan Y, Wang JS, and Chavin KD. Effect of St John’s wort on drug metabolism by induction of cytochrome P450 3A4 enzyme. Jama 290.11 (2003): 1500-1504. DOI: 10.1001/jama.290.11.1500

Ramakanth GS, Uday Kumar C, Kishan PV, and Usharani P. A randomized, double blind placebo controlled study of efficacy and tolerability of Withaina somnifera extracts in knee joint pain. Journal of Ayurveda and integrative medicine 7.3 (2016): 151-157. DOI: 10.1016/j.jaim.2016.05.003

Scudder, John. Specific Medication and Specific Medicines, 1870. ISBN:

Sharma AK, Basu I, and Singh S1. Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial. The Journal of Alternative and Complementary Medicine (2017). DOI: 10.1089/acm.2017.0183

Szegedi A, Kohnen R, Dienel A, and Kieser M. Acute treatment of moderate to severe depression with hypericum extract WS 5570 (St John’s wort): randomised controlled double blind non-inferiority trial versus paroxetine. Bmj 330.7490 (2005): 503. DOI: 10.1136/bmj.38356.655266.82

Woelk, Helmut. Comparison of St John’s wort and imipramine for treating depression: randomised controlled trial. Bmj 321.7260 (2000): 536-539. PMCID: PMC27467

Wolfson P and Hoffmann DL. An investigation into the efficacy of Scutellaria lateriflora in healthy volunteers. Alternative therapies in health and medicine 9.2 (2003): 74. PMID: 12652886

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