LAUSR

Abstract The aerial parts of rock hyssop (Hyssopus officinalis subsp. aristatus (Godr.) Nyman), well-known for bearing essential oil-producing glands, are also rich in phenol and polyphenol compounds. These latter, still rarely studied in rock hyssop and other hyssop species, markedly differ based on the plant collection site. In fact, their biosynthesis, maximized in the wild, is finely regulated by multiple abiotic and biotic factors. In this context, to reach an accurate and deep understanding of the polyphenol constitution of a homemade-like preparation (HOEE) from rock hyssop growing wild in Southern Italy, analyses, based on ultra-high pressure liquid chromatography coupled with high-resolution mass spectrometry (UHPLC HRMS), were carried out. HOEE mainly consisted of hydroxycinnamoyl derivatives (57.2%), among which some different and never reported coumarin and lignan compounds. Dicaffeoyl quinic acids were the main chlorogenic compounds, whereas flavonoid glycosides and methoxyflavonoids were the less abundant compounds. The preliminary assessment of HOEE antiradical properties through differen t-test tube assays provided a solid basis for originally exploring its antioxidant activity towards differentiated Caco-2 cells. Experimental evidence on genoprotective activity of hyssop aerial parts, herein testified for the first time, raised the potential of their using as a functional food for oxidative stress-induced diseases prevention.