Antioxidant and cytoprotective compounds from Berberis vulgaris (barberry).

Activity-guided fractionation of an EtOAc-soluble partition of the MeOH extract from the root bark of Berberis vulgaris L. (barberry), using a hydroxyl radical-scavenging assay, led to the isolation and identification of three phenolic compounds of a previously known structure, N-(p-trans-coumaroyl)tyramine, cannabisin G and (+/-)-lyoniresinol. Of these, cannabisin G and (+/-)-lyoniresinol exhibited antioxidant activity in this bioassay. Furthermore, it was found that cannabisin G showed cytoprotective activity in cultured MCF-7 cells modulated by hydrogen peroxide.