Valerian –  favourable effects on cognitive function

Valerian (Valeriana officinalis) root is well known for its applications in anxiety or insomnia, for which it has been used for thousands of years. Its anti-anxiety (anxiolytic) and sedative effects are mainly attributed to modulation and enhancement of the neurotransmitter GABA (gamma amino butyric acid), which prevents overstimulation of neurons implicated in anxiety and seizure disorders such as epilepsy. Behavioural studies in mice and clinical trials in humans are now expanding our understanding of this notable herb, and revealing other potential applications of relevance to modern day health gaps and needs.

One of these was a behavioural study in aged mice using a water maze performance test, reflective of spatial memory and the ability to cope with stress(1). Administration of valerian or valerenic acid improved the preferential exploration of new objects in a test of object recognition, and enhanced escape latency, swimming speeds, platform crossings, and a spatial preference for the target quadrant. These changes were accompanied by reduced blood levels of the stress-induced adrenal hormone corticosterone, and increased growth of nerve cell precursors (neuroblasts). The results suggest Valerian may help performance in stressful situations and moderate some of the less desirable neurological and physiological changes associated with becoming elderly, such as reduced cognitive function and confidence. This suggests adaptogenic (improved stress-coping ability) and possible nootropic (cognitive enhancing) properties for Valerian.

Other studies reporting anticholinesterase (cholinergic enhancement) activity, thought to be a mechanism of anti-dementia effects, and nerve growth stimulation by various Valerian iridoid and sesquiterpenoid constituents, further support such actions(2, 3).

Potential benefits of Valerian on cognitive function in patients undergoing certain forms of surgery, have also been revealed in a recent clinical trial(4).  Surgery is a stressful event, particularly so for patients with cardiovascular disease undergoing coronary artery bypass surgery. The trial involved 61 patients aged 30-70 years who underwent elective coronary artery bypass graft surgery using cardiopulmonary bypass. Patients received either one valerian capsule containing 530 mg valerian root extract (1,060 mg/daily), or a placebo capsule twice daily for 8 weeks. Cognitive brain function was evaluated prior to surgery then at 10 days and 2 months post surgery, using a test known as “Mini Mental State Examination (MMSE)”.

Following Valerian treatment, the mean MMSE score dropped from 27.03 in the preoperative period to 26.52 at the 10th day, then increased to 27.45 at the 60th day. This return to a normal MMSE was greater than that measured in the placebo group, in which the mean MMSE score fell from 27.37 at  baseline to 24 at day 10, and increased only slightly to 24.83 on the 60th day. This clinical trial provides evidence that Valerian may prevent early postoperative cognitive dysfunction after coronary artery bypass surgery. Given the high burden on the healthcare system and patients of such surgical procedures, further investigations using adjunctive Valerian in this and other forms of surgery, are warranted.

While unlike most sedative drugs Valerian shows little signs of impeding performance or producing an unwanted hangover effect the next day, until recently no study has specifically investigated these potential adverse effects.  Outcomes from a placebo-controlled clinical trial by Californian researchers in which participants received a dose of either 1600mg valerian or placebo then underwent a driving simulator, field sobriety and other tests of visual reactions and performance, are therefore of interest(5). No significant differences were recorded between groups in the simple visual reaction test or sleepiness scales, standardised field sobriety test total and individual test failure rates. This suggests a single dose of 1600mg valerian is unlikely to impair driving performance, in the way that alcohol or sedative drugs are known to do.

Finally, it is noted that Valerian’s reputation as a useful medicine in humans has attracted the attention of U.S. biotechnology researchers recently, who in a quest for new anti-anxiety agents have genetically engineered a strain of the E coli bacteria, to produce substantial quantities of the valerenic acid precursor valerenadiene(6, 7).

 

Refs:

  1. Nam SM et al, Exp Gerontol. 2013;48(11):1369-77
  2. Chen HW et al, 2016;110:142-9.
  3. Dong FW et al, Phytochemistry 2015; 118: 51-60.2015
  4. Hassani S et al, Psychopharmacology (Berl). 2015;232:843-50
  5. Thomas K, Accid Anal Prev 2016; 92:240-244.
  6. Nybo SE et al, J Biotechnol. 2017 Nov 20;262:60-66. doi: 10.1016/j.jbiotec.2017.10.004. Epub 2017 Oct 5.
  7. Ricigliano V et al, Phytochemistry 2016; 125:43-53.
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Why Herbs Should Be the First Choice of Treatment for Acute Anxiety

Anxiety can manifest in a wide range of ways. Apart from the internal emotional fearfulness, symptoms can include irritability, agitation, muscle tension, palpitations, sweating, insomnia, breathlessness, poor concentration, reduced socialisation and ability to undertake everyday activities. It is the most prevalent mental health disorder affecting children and adults, but many more people are dealing with problematic anxiety symptoms without any diagnosis.

In our increasingly changing world, where our daily exposure to stressful stimuli and life challenges can produce a rising barometer of worries, anxiety is often a major impediment to leading a fulfilling and happy life. Like most other health woes, humans have long pursued various practices to help overcome anxiety, the most popular of which is alcohol. Then there are drug medications, which have long been used to relieve anxiety, and remain widely prescribed.

Barbiturates were the first of these, sedative and anticonvulsant drugs which became popular particularly with sleep-deprived young mothers in the middle of last century, but which lead to the overdose deaths of thousands of people, including Elvis Presley and Marilyn Monroe. The next day ‘hangover effect’ from barbiturates was also always a problem, and development of a new chemical group of anxiolytic (anti-anxiety) and sedative drugs known as the benzodiazepines, lead to these superceding the barbiturates for the treatment of anxiety and insomnia. Benzodiazepines seem to act predominantly through stimulating GABA (gamma amino butyric acid) receptors in the central nervous system, and the commercialisation of Valium® (diazepam) by Roche in 1963 marked the start of a period during which this and other benzodiazepine drugs such as lorazepam, alprazolam and clonazepam began to be widely prescribed by GP’s and psychiatrists for anxiety and sleep difficulties. Between 1969 and 1982 Valium® was the most prescribed drug in the U.S., during which time Roche’s share price soared.

While safer than barbiturates, and effective as a ‘quick fix’ for anxious feelings or insomnia, safety concerns for benzodiazepines soon emerged. Feelings of fatigue, or a hangover the following day when taken as sleeping tablets, and a wide range of other side effects are all too common experiences. Most significant of these is the development of tolerance when they are used for more than a short period of time. As anyone who has been through it will testify, withdrawing from long term benzodiazepine use is a hugely stressful, unpleasant and often very protracted experience.

Feelings of depression can both contribute to or arise from excessive anxiety, and it is not uncommon for feelings of low mood and a low tolerance to stress, to be experienced together with anxiety. Apart from GABA, neurotransmitters such as serotonin, adrenaline and dopamine are intrinsically involved in influencing our emotions and mood, interacting together in complex ways that scientists still have little understanding of. It is therefore not surprising that many SSRI’s (selective serotonin reuptake inhibitor) drugs, used primarily as antidepressants, can have an anxiolytic effect in some people, and in many countries, these are often prescribed instead of or together with benzodiazepines, for anxiety conditions.

While sometimes effective as anxiolytics and less likely to produce adverse effects than most older generation tricyclic antidepressants, some find that SSRI’s can cause or increase anxiety feelings, or experience any one or more of a wide range of unpleasant side effects including insomnia, weight gain, emotional numbing or sexual dysfunction.

Another class of non-benzodiazepine sleeping tablets, the so-called  ‘Z-drugs’ such as zopiclone and zolpidem, have become popular in recent years, and while initially thought to be less habit-forming than benzodiazepines, they can also be very difficult to withdraw from after more than short-term use.

A large number of herbs have been traditionally used for nervous conditions and their anxiolytic effects, several of which have been shown in clinical trials to be beneficial as anxiety treatments. These include Chamomile, Skullcap, Passionflower, Valerian, Kava, Lemon balm and Withania.  Despite the number of well-designed trials undertaken to date being relatively low, and results sometimes variable depending on the particular herbal product(s) and dosages used, results are encouraging and in all cases show a better safety profile than for comparable anxiolytic drugs.

Of these, Kava (Piper methysticum), is the most studied, and is a non-addictive anxiolytic with great potential to treat anxiety. Its effectiveness in treating anxiety has been affirmed through several clinical trials and meta-analysis(1-3). While case reports of liver toxicity associated with kava usage lead to its restriction in some countries at the end of last century, use of the wrong plant part as raw material, or use in combination with alcohol or various drugs, were likely contributory factors. Also the frequency of such adverse events reports was substantially less than that for paracetamol, a commonly used analgesic.

Aerial parts of the herb Passionflower (Passiflora incarnata), have also been taken for anxiety for many centuries, and in a trial involving 36 outpatients with generalized anxiety disorder, it was as effective as the benzodiazepine drug oxazepam, but unlike oxazepam caused no impairment of job performance(4).

Roots of the herb Withania (Withania somnifera, Ashwagandha), have a subtle but powerful nervous system and adrenal tonic action, which insulates the nervous system from stress, and enables the adrenal glands to be better prepared to respond appropriately to stressful stimuli. A large number of scientific papers now support its applications for stress-associated anxiety conditions, including several recent human clinical trials(5,6).

While further studies involving greater participant numbers and longer term treatment are needed to identify optimal dosages and phytochemical makeup of the treatments involved, the fact that most herbal anxiolytic agents are safe and have the same or only a slightly higher incidence of adverse effects to placebo, is clear. It is therefore logical that before reverting to drug medications, more likely to produce unwanted adverse effects and in some cases long term dependency, herbal anxiolytics should be tried, in anxiety conditions.

Refs:

  1. Sarris J, Aust NZ J Psychiatry 2011; 45(1):27-35.
  2. Sarris J, J Clin Psychopharmacol 2013; 33(5):643-648.
  3. Savage K et al, Trials 2015; 16:493.
  4. Akhondzadeh S et al, J Clin Pharm Ther 2001; 26(5):363-367.
  5. Chandrasekhar K et al, Indian J Psychol Med 2012; 34(3):255-262.
  6. Pratte MA et al, J Altern Complement Med 2014; 20(12):901-908