Chronic oral administration of ginseng extract results in behavioral change but has no effects in mice models of affective and anxiety disorders

Ginseng is a popular 'tonic' herb in Chinese traditional medicine with diverse biological activity. The core of ginseng's therapeutic abilities is thought to be its neuroprotective actions in increasing cellular resilience. These actions coincide with novel theories of affective and anxiety disorders and raise the possibility that ginseng may serve as medication for these common and devastating diseases. The present study was designed to explore the possible effects of chronic ginseng extract, administered in a clinically relevant schedule (similar to antidepressants) in animal models of affective and anxiety disorders. Groups of mice received chronic oral treatment with ginseng extract (500 mg/kg/day for 3 weeks) and were tested in a large open field, in the emergence test for anxiolytic activity, the forced swim test for antidepressant activity and the amphetamine hyperactivity test for mood stabilizing activity. Chronic ginseng had a significant effect on reducing spontaneous locomotor activity in the open field test but not on the distribution of activity and had no influence on the performance of mice in any of the specific models. Although the extract used in this study contained significant levels of ginsenosides, detailed analysis of the brain levels of the active ingredients of ginseng may be needed to make a far reaching conclusion. However, the doses and schedule of administration of ginseng used in the present study induced some behavioral changes but did not influence affective- and anxiety-like measures. Copyright (c) 2006 John Wiley & Sons, Ltd.