Natural deep eutectic solvents-mediated extraction of rosmarinic acid from Lamiaceae plants: Enhanced extractability and anti-inflammatory potential

Species from the Lamiaceae family (mint, sage, savory, rosemary, etc.) are widely used as culinary spices and teas and are recognized as a rich source of bioactive phytochemicals, especially rosmarinic acid (RA). In recent years, there is a tendency to reduce the use of solvents and processes that may be toxic and harmful to the environment. This study investigates the potential of the use of eco-friendly natural deep eutectic solvents (NADES) and ultrasound-mediated approach in the extraction of rosmarinic acid from Lamiaceae species. The chromatographic analysis demonstrated the promising ability of choline chloride-based NADES as RA extraction solvents. The majority of the prepared ready-to-use NADES extracts protect the erythrocyte membrane from lyses and showed pronounced antioxidant activity. Principal component analysis (PCA) showed that the DPPH and FRAP activities of extracts were related to RA, while other extracted compounds were responsible for ORAC and antihemolytic activity. Interestingly, pure NADES reduced the level of inflammatory mediator PGE2 in lipopolysaccharide (LPS)-stimulated monocytes. A solubility study of pure RA indicates that NADES may serve as an alternative to organic solvents.