Anti-stress effect of astragaloside IV in immobilized mice

Abstract

Ethnopharmacological relevanceAstragaloside IV, a major component extracted from the roots of Astragalus membranaceus (AM), possesses anti-inflammatory, anti-oxidative, anti-fibrotic, anti-infarction and immunoregulatory effects. To clarify anti-stress effect of AM, anxiolytic and anti-inflammatory effects of 80% ethanol extract of AM and astragaloside IV were investigated in immobilization stress model. Materials and methodsThe mice were orally administered with AM (50, 200, and 500mg/kg), astragaloside IV (5, 10, and 20mg/kg) and buspirone, a positive drug, 1h before immobilization treated for 2h. For anxiolytic activity assay, EPM test was performed in mice. For anti-inflammatory activity assay, serum levels of corticosterone, IL-6 and TNF-α were measured using ELISA kits. ResultsAM extract and astragaloside IV increased dose-dependently time spent on open arms and open arm entries in the EPM test. Anxiolytic effects of AM extract (500mg/kg) and astragaloside IV (20mg/kg) were comparable to those of buspirone (1mg/kg). Their anxiolytic effects were blocked by WAY-100635 (0.5mg/kg, i.p.), a 5-HT1A receptor antagonist (p<0.01), but not by flumazenil (3mg/kg, i.p.) and bicuculline (0.5mg/kg, i.p.), GABAA receptor antagonists. AM extract and astragaloside IV also reduced serum levels of corticosterone, IL-6 and TNF-α dose-dependently. ConclusionsAM, particularly astragaloside IV, may ameliorate immobilized stress-induced anxiety and inflammation.