Ashwagandha
Ashwagandha (Withania somnifera) is an annual evergreen shrub of the nightshade family. It goes by many names, including ginseng and winter cherry, and is native to India, the Middle East and parts of Africa. The name Ashwagandha translates to ‘horse smell’ in Sanskrit, referring to the horsey smell of the root itself, and the medicinal properties that are said to give the strength and vitality of a horse.
Modern research shows that Ashwagandha has potent anxiolytic (anti-anxiety) effects. This may be due to the withanolides found in the extract, which are thought to activate GABA receptors in the brain that help boost resistance to stress. There is substantial evidence that Ashwagandha lowers subjective experience of stress and anxiety. It may also reduce cortisol levels, insomnia, fatigue, and symptoms of depression.
Ashwagandha for Stress & Anxiety Reduction
A Standardized Withania Somnifera Extract Significantly Reduces Stress-Related Parameters in Chronically Stressed Humans: A Double-Blind, Randomized, Placebo-Controlled Study
This 16-month trial was the first study to evaluate the therapeutic benefits of standardized WS extract in human subjects using modern clinical methods. Researchers tested the effects of Ashwagandha on chronically stressed humans and assessed subjects using a modified Hamilton Anxiety Scale. Subjects were split into placebo, or 125 mg QD, 125 mg BID, or 250 mg BID.
Researchers measured biochemical and clinical variables at day 1 and at day 60. They found that the 125 mg QD Ashwagandha group had a significant decrease in the Hamilton Anxiety Scale, serum cortisol, serum C-reactive protein, pulse rate, and blood pressure. Subjects felt less fatigue, flushing, perspiration, loss of appetite, headache and muscle pain, feelings of impending doom, palpitations, dry mouth, sleeplessness, forgetfulness, irritability, and inability to focus.
The results show that Ashwagandha reduces ‘experiential’ feelings of stress and anxiety, as well as many of the more difficult stress-related symptoms.
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
This study in India tested Ashwagandha extract on 64 men and women (ages 18-64) with a history of chronic mental stress. The study aimed to test the safety and efficacy of the extract as a treatment for stress and anxiety. Researchers measured serum cortisol levels and assessed participants’ scores on standard stress-assessment questionnaires.
After 60 days of daily treatment, the Ashwagandha group achieved a significant reduction on all stress-assessment scales, and lower serum cortisol levels. These findings suggest that high-concentration Ashwagandha is a safe, effective way to improve resistance to stress and enhance quality of life.
A Double-blind, Placebo-controlled Evaluation of the Anxiolytic Efficacy Of An Ethanolic Extract Of Withania Somnifera
This study tested the efficacy of ethanolic extract of Ashwagandha in patients (ages 30-64) suffering from anxiety disorders. After six weeks of taking two daily doses of the root extract, subjects experienced improvements in symptoms of anxiety and depression. They concluded that Ashwagandha has beneficial anxiolytic properties, indicating its potential to treat anxiety disorders.
A Randomized Double-Blind Placebo-controlled Study of Ashwagandha on Generalized Anxiety Disorder
This 16-month trial-tested Ashwagandha granules on subjects (ages 16-60) with Generalized Anxiety Disorder (GAD). After 60 days of daily treatment, the 44 patients in the Ashwagandha group showed significant improvement on the Hamiton’s Anxiety Rating Scale, as well as improvement in anxious mood and tension.
Although there was no statistically significant difference in the placebo group, there was a significant improvement in anxious mood and tension in the Ashwagandha group and greater improvement in every symptom. These results show that Ashwagandha does improve feelings of anxiety, and can be effective in the management of GAD.
Chamomile
Chamomile has a rich history of medicinal use, from the ancient Egyptians, who used it to treat the common cold, to the ancient Greeks and Romans. Though there are several strains of chamomile, the most common today are Roman (Chamaemelum nobile) and German (Matricaria recutita), the latter being more commonly used for medical purposes.
Chamomile is mainly used for its calming effect, to relieve stomach issues, to soothe inflammation, and to treat skin conditions. The anti-anxiety effects of chamomile have drawn clinical attention, with recent studies demonstrating its usefulness for reducing stress, insomnia, and symptoms of depression.
The sedative effects of chamomile may be due to the fact that it contains apigenin, which binds to benzodiazepine receptors and boosts GABA A receptors–responsible for calming the body before sleep. Apigenin may also block the MAO enzyme, which increases the availability of monoamines such as serotonin. Chamomile also includes the flavonoid Chrysin, shown to have anti-anxiety effects in animal studies.
Chamomile to treat Stress & Anxiety
Long-term chamomile (Matricaria chamomilla L.) treatment for generalized anxiety disorder: A randomized clinical trial
This study investigated the use of long-term chamomile to prevent symptom relapse of Generalized Anxiety Disorder (GAD). In phase 1, 179 outpatients with mild-to-severe GAD received 12 weeks of open-label therapy with chamomile extract. Phase 2 included those who responded to chamomile treatment. Participants were randomized to receive either 26 weeks of further chamomile therapy or placebo.
Of the 179 subjects, 51.9% responded to treatment and continued with Phase 2. During the follow-up, those in the chamomile group maintained significantly lower GAD symptoms than placebo, with significant reductions in body weight and mean arterial blood pressure. Researchers concluded that long-term chamomile is safe and significantly reduces moderate-to-severe GAD symptoms.
A Randomized, Double-Blind, Placebo-Controlled Trial of Oral Matricaria recutita (Chamomile) Extract Therapy for Generalized Anxiety Disorder
This study tested the efficacy and tolerability of chamomile extract therapy in patients with mild-to-moderate GAD. 57 outpatients were randomized to receive either double-blind chamomile extract or placebo therapy for 8 weeks. Researchers measured the difference in change over time in Hamilton Anxiety Rating (HAM-A) scores, changes in the Beck Anxiety Inventory, psychological wellbeing, and Clinical Global Impression Severity scores.
The study found a significantly greater reduction in total HAM-A scores in the chamomile group. They observed a positive change in all outcome measures and concluded that chamomile may reduce symptoms of anxiety in patients with mild-to-moderate GAD.
Chamomile (Matricaria recutita) May Have Antidepressant Activity in Anxious Depressed Humans – An Exploratory Study
This randomized, double-blind, placebo-controlled study, investigated the antidepressant action of oral chamomile extract in patients with co-morbid anxiety and symptoms of depression. 57 patients received either chamomile extract or placebo therapy. Researchers measured clinically meaningful changes over time in the Hamilton Depression Rating (HAM-D). The results showed a significantly greater reduction in mean total HAM-D scores and HAM-D core depression score for chamomile compared to placebo in all subjects. The study concluded that chamomile may have considerable antidepressant activity, as well as the already confirmed anti-anxiety activity.
Mimosa Bark
Mimosa Bark (He Huan Pi) has a long history of use in Traditional Chinese Medicine. In China, the bark is known as ‘collective happiness bark’, indicating its traditional use for lifting the mood and calming the body. Its earliest recorded medicinal use stretches back to the 2nd century. Researchers have been investigating the main ingredient of Mimosa Bark, Albizzia Julibrissin Durazz, as a potential therapy for anxiety and stress as its active ingredient, A.julibrissin, contains calming flavonoids and has been reported to lower stress levels through the HPA axis and monoamine neurotransmitters.
Monoamine Neurotransmitters
Animal studies show that A.julibrissin is able to regulate monoamine neurotransmitters (serotonin, dopamine, and norepinephrine) and their metabolites in stress-induced rats, alleviating behaviors driven by stress and fear. A.julibrissin was found to have anxiolytic (anti-anxiety) effects due to its ability to activate the 5-HT1A receptor. This is a subtype of the serotonin receptor which appears to be vital in managing anxiety and panic.
The HPA Axis
A.julibrissin has been found to work through the hypothalamic-pituitary-adrenal (HPA) axis, which is activated when the brain reacts to stress. Under stress, the hippocampus (one of the pathways that control this HPA axis) can inhibit the influence of hypothalamic CRF-containing neurons, which play a vital role in fear and emotional memory. Since chronic stress has been found to increase CRF levels, this is the target for many anxiolytic (anti-anxiety) medications. In an animal study on stress-induced rats, A.julibrissin was found to decrease CRF levels and cortisol levels.
Flavonol Glycosides
Quercetin and Isoquecitirn are two flavonol glycosides found within A.julibrissin. Flavonols are a subclass of flavonoids, which exert anti-inflammatory effects that protect cells from oxidative damage. Oxidative stress can lead to the development of depression and anxiety, and inflammation and stress are closely linked, as inflammation is a natural response to stress.
Quercetin has been found in studies to exert anxiolytic and cognitive enhancing effects and impact depressive-like and anxiety-like responses induced by stress. Isoquencitirin has been found to produce a sedative-like response in animal studies.