Abstract

The aim of this research was to develop a new extraction method combining hydrophobic deep eutectic solvent (HDES)-based microemulsion systems with microwave-assisted extraction (MAE) technology to enhance the extraction efficiency of isoangustone A (IsoA) from the leaves of the Thai medicinal plant Derris scandens (Roxb.) Benth. (Fabaceae). The research optimized the extraction parameters, characterized the microemulsion formulations, and evaluated the anti-inflammatory potential of the preparations in vitro. The HDES (menthol:lactic acid, 1:2 mol ratio)-microemulsion formulation demonstrated enhanced extraction efficiency over conventional ethanol-based methods. This formulation achieved a yield of IsoA of 6.52 μg/mg, surpassing the 5.76 μg/mg yield obtained through ethanol extraction. Response Surface Methodology (RSM) modeling enabled precise optimization of the extraction parameters, reaching 91.2 % predictive accuracy. Physicochemical characterization revealed that HDES-based microemulsions maintained 23.1-50.7 nm size, facilitating an enhanced bioavailability profile. The incorporation of D. scandens leaf extracts into the HDES (menthol:lactic acid, 2:1 mol ratio)-based microemulsion provided optimal inhibition of LPS-induced NO production in RAW264.7 macrophages, with IC<inf>50</inf> values (9.07±2.26 μg/mL) substantially lower than the DMSO-solubilized counterparts (53.7±3.8 μg/mL) demonstrating enhanced cell penetration resulting in improved extraction. This integrated approach represents a significant advancement in sustainable extraction technology, offering enhanced recovery of bioactive compounds while preserving their biological properties for further assessment.