Bioactive extracts from Mediterranean agro-waste obtained by subcritical water: Chemical profiling and cellular anti-inflammatory effects

This study optimized subcritical water extraction (SWE) to recover bioactive compounds from Mediterranean agro-industrial by-products: citrus peels, artichoke bracts, and date pits. Extraction parameters were optimized using response surface methodology to maximize phenolic content and antioxidant capacity. The resulting extracts were characterized by their total phenolic and flavonoid contents, and phenolic profiles analyzed by HPLC. Despite compositional differences, all SWE extracts exhibited high phenolic contents (>126 mg GAE/g) and strong antioxidant activity as evaluated by DPPH (>132 mg TE/g). The antioxidant potential observed in chemical assays was complemented by the ability of the extracts to significantly reduce ROS and NO production in LPS-stimulated RAW 264.7 macrophages. These results highlight an efficient and integrated strategy to valorize Mediterranean by-products using an optimized green technology SWE to produce extracts with promising antioxidant and anti-inflammatory properties.