Neuropharmacological Studies on Ethanol Extracts of Valeriana officinalis L.: Behavioural and Anticonvulsant Properties

An ethanol total extract of the roots of Valeriana officinalis L. in doses equivalent to 0.5–800 mg valerian root/kg b.w.i.p. was tested in male mice for possible neuropharmacological efficacy and in this respect compared with diazepam and haloperidol. The extract did not modify spontaneous motility, nociception or body temperature, and did not produce palpebral ptosis. However, it was anticonvulsant against picrotoxin (but not pentetrazol and harman) with an ED₅₀ between 4.5 and 6 mg/kg and it prolonged thiopental anaesthesia. After fractionation of the crude extract, the antipicrotoxin activity was present mainly in the methylene chloride fraction (ED₅₀=0.25 mg/kg). Pure valerenic acid (12.5 mg/kg b.w.i.p.) also exerted an antipicrotoxin effect.