Antioxidant Profiles of Vitis vinifera L. and Salvia triloba L. Leaves Using High-Energy Extraction Methodologies

The profiles of Vitis vinifera L. and Salvia triloba L. leaf extracts have been studied via photometric assays on the basis of their total phenolic and flavonoid content as well as of their radical scavenging and antioxidant activities. Ultrasound-assisted (UAE) and pressurized liquid extractions (PLE) were implemented for producing polar fractions from the plants, using different methanol-water and glycerol-water mixtures for UAE and PLE, respectively. Aqueous methanol was proved an effective solvent for the UAE of total phenolics and flavonoids as well as for increased radical scavenging and antioxidant activities. As for PLE, plain water was proved a more efficient solvent than hydroglycerolic mixtures. Overall, irrespective of the solvent(s) used, UAE extracts showed higher values compared with the PLE extracts for all the photometric determinations and for both plant species. Moreover, Salvia UAE and PLE extracts presented higher total phenolic and flavonoid contents, accompanied by higher radical scavenging and antioxidant activities, compared with Vitis extracts. The correlations among photometric results were also studied, indicating the categories of compounds that relate to the antioxidant and/or radical scavenging activities of the extracts. Mixtures of the examined extracts could be exploited as the basis of novel phytotherapeutic products in the cosmetic sector.