Neuroprotective constituents of Actaea acuminata (Wall. ex Royle) H. Hara roots

The methanol extract and its ethyl acetate fraction (EAF) of Actaea acuminata (Wall. ex. Royle) H. Hara roots were reported to exhibit significant antianxiety, anticonvulsant and antidepressant activities, and mild sedative activity. But the constituents responsible for these activities have not been isolated. The present study was undertaken to isolate neuroprotective compounds of A. acuminata following bioactivity-guided-fractionation. The column chromatography of EAF and its sub-fractions led to the isolation of four phenolic compounds (bergenin, gallic acid, acetyl bergenin and racemic mixture of diacetyl bergenin), which were characterized by IR and NMR spectral analysis. All the compounds exhibited significant antianxiety and antidepressant activities with respect to control. The gallic acid and bergenin did not show anticonvulsant activity, whereas acetyl bergenin and racemic mixture of diacetyl bergenin exhibited significant anticonvulsant activity. Neuropharmacological activities of A. acuminata are attributed due to polyphenolic compounds. Scientific validation of traditional claims of A. acuminata has opened up roadmap of research for the development of CNS affecting lead molecules.

Keywords: Actaea acuminata; Himalayan Baneberry; anticonvulsant; anxiolytic; sedative.