Tagara is a single-herb formulation prepared from the rhizome extract of Tagara (Valeriana wallichii). Tagara exhibits sedative effect due to the presence of hesperidin (HN), a natural flavanone glycoside.
Pharmacological Actions
1. Restores circadian rhythm
5-Hydroxytryptamine-5a (5-HT) receptor is distributed throughout the brain. The receptor concentrations are particularly intense in the suprachiasmatic nucleus of the hypothalamus, the site of the biological clock that drives circadian rhythms. Serotonin is well known to modulate sleep wake cycles and circadian rhythms in the human brain through a G-protein-coupled receptor family. Valerian and valerenic acids of V wallichii are new partial agonists of the 5-HT receptor. Release of 5-HT during the sleep-wake cycle initiates a cascade of genomic events in some hypnogenic neurons located in the preoptic area and the neighboring suprachiasmatic nucleus including vasoactive intestinal polypeptide and GABAergic mechanism.
2. Sedative activity
The sedative effect of V wallichii is due to its natural flavanone glycoside 2S(-)-7-rhamnoglucosyl hesperetin or HN.2 The sedative activity of HN is potentiated by simultaneous administration of valerenic acid.³ MA has been proved to have medium to high affinity for the BZD-bs, as a result of which it reduces excitement and produces calmness.
3. Anxiolytic activity
MA isolated from V wallichii has the ability to bring about an anxiolytic effect. MA is a natural flavonoid derivative that serves as a ligand for the BZD-bs of the GABA-A receptor; it has a high affinity for BZD-bs. MA has thus, been able to potentiate the sleep enhancing property of HN.
4. Antidepressant activity
The antidepressant property of V wallichii is due to the activation of GABA-A receptors, which are molecular substrates for the regulation of vigilance and anxiety. Several terpenoid GABA derivatives are known to induce inherent antidepressant action.
Indications
- Disturbed sleep
- Insomnia
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