Optimization of Bioactive Phenolics Extraction and Cosmeceutical Activity of Eco-Friendly Polypropylene-Glycol–Lactic-Acid-Based Extracts of Olive Leaf

Olive leaves are a treasure trove of skin-loving phenolics—and now, scientists have found a green way to unlock them without harsh solvents.

Olive leaves are packed with phenolic compounds that benefit skin health and appearance. But extracting them usually involves toxic solvents and energy-hungry evaporation. A new study flips the script: researchers developed an eco-friendly extraction method using a blend of polypropylene glycol (PPG), lactic acid (LA), and water—all safe, bio-based ingredients.

They optimized the process by tweaking solvent composition, extraction time, and technique, comparing magnetic stirring with ultrasound-assisted extraction. Using HPLC and spectrophotometry, they measured key phenolics like oleuropein and verbascoside. Three extracts were then tested for antioxidant and skin-related enzyme inhibition.

The results were impressive: all extracts strongly inhibited elastase, collagenase, tyrosinase, and lipoxygenase—enzymes linked to aging, pigmentation, and inflammation. The star performer was the extract richest in phenolics, obtained via magnetic stirring for 20 minutes with 0.8 g of leaves in 10 mL of a PPG/LA/water mixture (28.6/63.6/7.8, w/w/w). A close second used the same conditions but with 0.42 g of leaves.

Crucially, the solvent mixture itself contributed to the enzyme-inhibitory activity, meaning the extracts could be used directly in cosmetic products—saving time and energy by skipping solvent evaporation. This is a win for both skin and planet.

Key Points

• Eco-friendly PPG/LA/water solvent extracts olive leaf phenolics effectively.
• Optimal extract inhibited elastase, collagenase, tyrosinase, and lipoxygenase.
• Extracts usable directly in cosmetics, saving energy and time.