Comprehensive Evaluation of Antioxidant Potential of 10 Salvia Species Using High Pressure Methods for the Isolation of Lipophilic and Hydrophilic Plant Fractions

Common sage (Salvia officinalis) is a well-known source of antioxidants and other bioactive compounds, while many other species within the Salvia genus have been poorly studied. The total content of phenolic compounds (TPC) and antioxidant capacity indicators were evaluated for the extracts of 10 Salvia spp. consecutively isolated by supercritical carbon dioxide (SFE-CO2) and pressurized liquid extraction with ethanol and water. Antioxidant properties of solid plant material were evaluated by the direct antioxidant capacity measurement by the so-called QUENCHER method. Total antioxidant capacity values were calculated by integrating the results obtained for all extracts and the whole plant material. TPC and antioxidant capacity of the extracts were greatly dependent on the plant species and extraction solvent. Ethanol extracts possessed significantly higher antioxidant capacity and TPC comparing to the extracts isolated with other solvents. In general, all studied Salvia species demonstrated strong antioxidant capacity; however, the antioxidant potential of such species as S. forsskaolii and S. verticillata was the highest and comparable with that of S. officinalis. The majority of studied Salvia species may be considered as promising sources of functional ingredients to be used in human nutrition for functional food and nutraceutical formulations.