Cholinesterases inhibitory and antioxidant activities of Harpagophytum procumbens from in vitro systems

A previous report showed that extracts of cell suspension and transformed root cultures of Harpagophytum procumbens (commonly known as Devil's claw), an African plant with high medicinal value, exhibit strong antiinflammatory characteristics. The present work tests the ability of extracts, phenylethanoid-containing fractions and the major phenylethanoid glycoside isolated from the Devil's claw cultures, to inhibit acetylcholinesterase and butyrylcholinesterase, and the antioxidant activity in iron-related systems (e.g. ferric-reducing antioxidant power and ferrous ion-chelating capacity). The results indicated that the phenylethanoid fractions may be attractive for various commercial purposes since they displayed significant cholinesterase inhibitory activity (even higher than that of pure galanthamine in the case of butyrylcholinesterase inhibition assay). Crude methanolic extracts from cell and hairy root cultures of Devil's claw exhibited strong ferrous ion-chelating capacity (1.5-2 times higher than pure butylated hydroxyanisole, used as positive standard).