A Valepotriate Fraction of Valeriana glechomifolia Shows Sedative and Anxiolytic Properties and Impairs Recognition But Not Aversive Memory in Mice

Plants of the genus Valeriana (Valerianaceae) are used in traditional medicine as a mild sedative, antispasmodic and tranquilizer in many countries. This study was undertaken to explore the neurobehavioral effects of systemic administration of a valepotriate extract fraction of known quantitative composition of Valeriana glechomifolia (endemic of southern Brazil) in mice. Adult animals were treated with a single intraperitoneal injection of valepotriate fraction (VF) in the concentrations of 1, 3 or 10 mg kg(−1), or with vehicle in the pre-training period before each behavioral test. During the exploration of an open field, mice treated with 10 mg kg(−1) of VF showed reduced locomotion and exploratory behavior. Although overall habituation sessions for locomotion and exploratory behavior among vehicle control and doses of VF were not affected, comparison between open-field and habituation sessions within each treatment showed that VF administration at 1 and 10 mg kg(−1) impaired habituation. In the elevated plus-maze test, mice treated with VF (10 mg kg(−1)) showed a significant increase in the percentage of time spent in the open arms without significant effects in the number of total arm entries. VF at 3 mg kg(−1) produced an impairment of novel-object recognition memory. In contrast, VF did not affect fear-related memory assessed in an inhibitory avoidance task. The results indicate that VF can have sedative effects and affect behavioral parameters related to recognition memory.