From Plant to Skin: Exploring Alnus glutinosa Extracts for Cosmeceutical Applications

This study explores the photoprotective and antioxidant potential of cosmetic emulsions formulated with Alnus glutinosa (black alder) extracts. Extraction of bioactive compounds was performed using Soxhlet, ultrasound-assisted, and microwave-assisted techniques with ethanol and water as solvents. The phytochemical profiles of the resulting extracts were characterized via UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and liquid chromatography-high-resolution mass spectrometry (LC-HRMS). The extracts were incorporated into oil-in-water emulsions and assessed for antioxidant activity using the DPPH radical scavenging assay, pH and viscosity stability, and color L*a*b* values. Among the extraction methods, ethanol-based Soxhlet extraction yielded the highest concentration of bioactive compounds and demonstrated superior antioxidant and photoprotective efficacy. This is the first report that evaluates the antioxidant properties of A. glutinosa-enriched emulsions, supporting their application as multifunctional, plant-derived cosmeceuticals for skin protection.