Evaluation of the effects of Astragalus mongholicus Bunge saponin extract on central nervous system functions

Ethnopharmacological relevance: In traditional medicine, Astragalus mongholicus (AM) has been used forthe treatment of general weakness, chronic illness, and to increase overall vitality.

Aim of the study: The present study investigated possible effects of the saponinfraction of AM on the centralnervous system. Moreover, its effects on locomotor activity, anxiety, and hippocampal morphology werestudied.

Material and methods: AM extract was tested for its effects on locomotor activity using the Moti-Test, forsituational anxiety in the elevated plus maze, and for anticonvulsant activity against acute pentylenetetrazole (PTZ)-induced seizures and in the PTZ kindling model.

Results: It was shown that AM (50, 100, 200 mg/kg) did not interfere with locomotor activity and situational anxiety as measured in the elevated plus maze. In these doses, AM significantly suppressedpentylenetetrazole (PTZ)-induced seizures (p < 0.05). Its anticonvulsant efficacy was also evident againstrepeated PTZ seizures (p < 0.05). This suggests potential therapeutic usefulness. After subchronic application, the number of cells in hippocampal CA1 was reduced, whilst the cell number in CA3 and hilusremained unaffected.

Conclusions: Doses of AM extract which did not interfere with locomotor acticity and situational anxietyappear to be useful in the treatment of convulsive disorders. The mechanisms underlying this effect onhippocampal morphology are not yet understood.