Effect of pretreatment and extraction method to obtain bioactive compounds from Casearia sylvestris leaves

This study aimed to determine the most effective combination of leaf pre-treatment, solvent, and non-conventional extraction technique to maximize the recovery of phenolic compounds and antioxidant activity from Casearia sylvestris. Two pre-treatment methods, oven drying and freeze-drying, were tested in combination with water and ethanol 40 % as solvents using maceration. The highest total phenolic content (TPC) and antioxidant activity (AA) were obtained with freeze-dried leaves and ethanol 40 % (56.24 ± 0.96 mgGAE/g and 78.85 ± 0.48%, respectively). These conditions were used to assess different non-conventional extraction methods, including ultrasound-assisted extraction and sonication at room temperature and 80 °C. Ultrasound-assisted extraction at 80 °C provided the highest TPC (70.45 ± 1.49 mgGAE/g) without compromising AA. Statistical analysis of results demonstrated that freeze-drying significantly preserves bioactive compounds, and ultrasound-assisted extraction enhances their recovery. The combination of freeze-dried leaves, ethanol 40%, and ultrasound at elevated temperature proved to be the most efficient and sustainable strategy in this study for obtaining phenolic-rich extracts from C. sylvestris. Next step of this research intend to use the extract with higher TPC and AA in a formulation of liquid spray dressing indicated for wound healing.