Sustainable extraction of polyphenol rich herbal blends using tunable natural deep eutectic solvents with antimicrobial evaluation and AGREEprep greenness assessment

The growing demand for natural and safe cosmetic ingredients has driven the exploration of multi-plant blends combined with green extraction technologies. In this study, Middle Eastern medicinal plants including Rhus coriaria , Coffea arabica , Peganum harmala , Origanum majorana , Moringa oleifera , Commiphora myrrha , Punica granatum , Carthamus tinctorius , Salvia officinalis , and Silybum marianum were extracted using citric acid- and lactic acid-based natural deep eutectic solvents (NADES). Eight NADES formulations were prepared and characterized for viscosity, pH, density, and conductivity prior to extraction. Phytochemical analyses, including total phenolic content (TPC), total flavonoid content (TFC), and high-performance liquid chromatography with diode-array detection (HPLC–DAD) profiling, demonstrated efficient recovery of polyphenols, particularly chlorogenic acid, with extraction efficiency influenced by NADES composition and hydrogen-bonding interactions. The antimicrobial activity of the extracts was evaluated against Staphylococcus aureus , Pseudomonas aeruginosa , and Candida albicans , showing bactericidal effects at low concentrations, with selected NADES systems exhibiting the lowest minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values. The antimicrobial effects are suggested to arise from a combined contribution of extracted phytochemicals and the physicochemical characteristics of NADES. The AGREEprep assessment (score = 0.64) supports the relative greenness of the extraction process compared to conventional approaches. Overall, this work presents a sustainable approach for extracting bioactive compounds from multi-plant systems using NADES, with potential applications in the development of environmentally conscious cosmetic formulations.