Valerenic acid
Valerenic acid is a sesquiterpenoid constituent of the essential oil of the Valerian plant.
Valerian is used as a herbal sedative which may be helpful in the treatment of insomnia. It is likely that several components of the plant contribute to the effect. Valerenic acid is thought to be at least partly responsible for the sedative effects.
Valerenic acid acts as a subtype-selective GABAA receptor positive allosteric modulator via a binding site in the transmembrane domain at the β+α− interface. At receptors expressed in Xenopus oocytes it was shown that only assemblies incorporating β2 or β3 subunits were stimulated by valerenic acid. Modulation of ion channel action was not significantly dependent on incorporation of α1, α2, α3 or α5 subunits.
At the 5-HT5A receptor valerenic acid acts as a partial agonist. This serotonin receptor subtype is distributed in the suprachiasmatic nucleus, a tiny brain region implicated in the sleep-wake cycle.
A study in 2006 found valerian extract as well as valerenic acid to inhibit NF-κB, a protein complex that controls the transcription of DNA, in HeLa cells. This was measured with the IL-6 / Luc assay as a measurement tool. The study mentioned that such inhibition may be connected to the reported anti-inflammatory action of the valerian plant.
