Valerian (herb) particular binding site. Hydrophilic extractions of the herb commonly sold over the counter, however, probably do not contain significant amounts of isovaltrate. Valerenic acid in valerian stimulates serotonin receptors as a partial agonist, including 5-HT which is implicated in the sleep-wake cycle. The chief constituent of valerian is a yellowish-green to brownish-yellow oil present in the dried root, varying in content from 0.5 to 2.0%. This variation in quantity may be determined by location; a dry, stony soil yields a root richer in oil than moist, fertile soil. The volatile oils that form the active ingredient are pungent, somewhat reminiscent
Valerian (emperor) and being soon after made prisoner, grew old in ignominious slavery among the Parthians." An early Christian source, Lactantius, thought to be virulently anti-Persian, thanks to the occasional persecution of Christians by some Sasanian monarchs, maintained that, for some time prior to his death, Valerian was subjected to the greatest insults by his captors, such as being used as a human footstool by Shapur when mounting his horse. According to this version of events, after a long period of such treatment, Valerian offered Shapur a huge ransom for his release. In reply, according to one version, Shapur was said to