Anxiolytic-Antidepressant Activity of Withania Somnifera

Anxiolytic-antidepressant activity of Withania somnifera glycowithanolides: an experimental study.
Bhattacharya SK1, Bhattacharya A, Sairam K, Ghosal S.
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Abstract
The roots of Withania somnifera (WS) are used extensively in Ayurveda, the classical Indian system of medicine, and WS is categorized as a rasayana, which are used to promote physical and mental health, to provide defence against disease and adverse environmental factors and to arrest the aging process. WS has been used to stabilize mood in patients with behavioural disturbances. The present study investigated the anxiolytic and antidepressant actions of the bioactive glycowithanolides (WSG), isolated from WS roots, in rats. WSG (20 and 50 mg/kg) was administered orally once daily for 5 days and the results were compared by those elicited by the benzodiazepine lorazepam (0.5 mg/kg, i.p.) for anxiolytic studies, and by the tricyclic anti-depressant, imipramine (10 mg/kg, i.p.), for the antidepressant investigations. Both these standard drugs were administered once, 30 min prior to the tests. WSG induced an anxiolytic effect, comparable to that produced by lorazepam, in the elevated plus-maze, social interaction and feeding latency in an unfamiliar environment, tests. Further, both WSG and lorazepam, reduced rat brain levels of tribulin, an endocoid marker of clinical anxiety, when the levels were increased following administration of the anxiogenic agent, pentylenetetrazole. WSG also exhibited an antidepressant effect, comparable with that induced by imipramine, in the forced swim-induced 'behavioural despair' and 'learned helplessness' tests. The investigations support the use of WS as a mood stabilizer in clinical conditions of anxiety and depression in Ayurveda.


https://www.ncbi.nlm.nih.gov/pubmed/11194174

https://www.researchgate.net/public...ifera_glycowithanolides_An_experimental_study

 

GABA is one of your neurotransmitters (like the more well known Dopamine and Serotonin).

GABA is one of the most widely accepted mediators of anxiety disorders.

In fact, a class of drugs (Benzodiazepine), work by enhancing the effect of GABA at the GABA receptor. These include drugs such as Xanax, Clonazepam, Valium, Ativan. These drugs are usually used for anxiety, insomnia and panic disorders.



When Withania somnifera interacts with GABA receptors, it binds to the receptors and produces the intended response.

Withania somnifera seems to work in a similar manner as drugs that target GABA receptors


Withania somnifera appears to be involved in signalling through the GABAA receptor, as its beneficial influences on sleep are abolished with GABAA antagonists and potentiated by GABAA agonists and the ability of Withania somniferato enhance GABAA signalling via diazepam has been noted elsewhere with 5µg of the methanolic extract and 100-200mg/kg oral Withania somnifera (mice). Acting through the GABAA receptors also underlies the ability of 400ng/mL of the methanolic extract to release GnRH.

This enhancement of GABAA signalling is similar to that seen with Scutellaria baicalensis, and while Withania somnifera has been noted to hinder GABA binding to the receptor (5mcg causing 20% inhibition, 1mg causing 100% inhibition) it enhances flunitrazepam binding (to the benzodiazepine binding site).

Withania somnifera appears to enhance signalling through GABAA receptors in a similar manner as Scutellaria baicalensis, which seem to underlie the sleep enhancement and possibly anxiolytic effects of Withania somnifera.