Antioxidant Activity of Supercritical CO2 Extracts of Helichrysum italicum

The antioxidant activity of supercritical CO2 extracts of H. italicum dried flower heads derived from the commercial drug and from plants grown in different areas of north-east Italy with different culturing conditions was determined. In particular, the characterization of the antioxidant activity was made by the DPPH and b-carotene bleaching test methods. The four kind of H. italicum extracts were also tested for their ability to scavenger superoxide radicals. All extracts showed, although with different importance, an antioxidant activity with all the methods performed. The supercritical extracts obtained from commercial dried H. italicum flower heads and from dried flower heads belonging to wild plants exhibited the highest activity. These results established H. italicum supercritical extracts as important antioxidant solvent-free matrices in alimentary (i.e., dietary, nutraceutical, flavouring) and cosmetic fields, as well as the value of coastal Mediterranean areas to serve as an exploitable source of important plant matrices.