Green Extraction of Greek Propolis Using Natural Deep Eutectic Solvents (NADES) and Incorporation of the NADES-Extracts in Cosmetic Formulation

What if the key to greener cosmetics lies in a natural resin collected by bees? Greek propolis, extracted with eco-friendly solvents, just proved it can power a cream with antioxidants—without the harsh chemicals.

Propolis, the bee-made resin, is a treasure trove of bioactive compounds, but traditional extraction often relies on organic solvents that are anything but green. This study flips the script: it combines ultrasound-assisted extraction with Natural Deep Eutectic Solvents (NADES)—a class of eco-friendly liquids made from natural ingredients like amino acids and organic acids. The goal? A cleaner, smarter way to unlock propolis's potential for cosmetics.

Five NADES were tested, and one stood out: L-proline/D,L-lactic acid. This solvent produced extracts with the highest total phenolic content and significantly stronger antioxidant activity than the others. The team then optimized the extraction using Experimental Design, tweaking time, propolis-to-solvent ratio, and water content to get the best yield.

When compared to a conventional hydroethanolic extract, the NADES-extract matched or even surpassed it in key phytochemicals like apigenin and naringenin, as shown by LC/MS/MS analysis. The usual catch—that NADES make it hard to isolate dry extracts—turned out to be a feature, not a bug. The NADES itself adds value, and the optimized extract was successfully incorporated into a cosmetic cream, with its antioxidant activity and organoleptic properties confirmed.

Key Points

• NADES L-proline/D,L-lactic acid gave highest antioxidant activity.
• Ultrasound-assisted NADES extraction is a green alternative.
• NADES-extract matched or beat conventional in key phytochemicals.