Polyphenols from Thelesperma megapotamicum and Their Antioxidant and Neuroprotective Activities

Polyphenols are attracting increasing attention in the discovery of useful agents for the treatment of neurodegenerative diseases. Thelesperma megapotamicum (Spreng.) Kuntze belongs to the family Asteraceae, which is known to have a high antioxidant capacity. The phytochemical investigation of T. megapotamicum revealed the presence of 1′-S-isobutyroxyeugenol isobutyrate, (1), lupeol, (2), 1′-S-acetoxyeugenol isobutyrate, (3), stigmasterol, (4), β-sitosterol, (5), eriodictyol, (6), luteolin, (7), and marein, (8), as major secondary metabolites. The neuroprotective activity of this species was studied by evaluating the inhibition in vitro of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and the antioxidant capacity of the sub-extracts and of the major metabolites isolated from them. The AChE and BChE inhibition were determined by Ellman’s method and the antioxidant activity by DPPH assay. The inhibitory activity against BChE and the antioxidant capacity of the polyphenols present in T. megapotamicum highlight this species as a promising source of active metabolites for the development of agents for the treatment of neurodegenerative diseases.