Optimization of ultrasound enzyme-assisted trehalose lipid extraction of Coptis alkaloids and evaluation of its anti-inflammatory effects

Coptidis Rhizoma (CR), a traditional Chinese medicine, has extensive pharmacological activity because it is rich in isoquinoline alkaloids. Nonetheless, the limited solubility of these alkaloids presents a significant challenge, hindering the full realization of CR's therapeutic potential through conventional extraction methods. To address this issue and enhance the solubility of the target compounds while optimizing extraction efficiency, this study employed an environmentally sustainable extraction technique, Ultrasound-Enzyme-Trehalose Lipid (UET), to synergistically extract five key alkaloids from CR. Based on the results of single-factor experiments, Box-Behnken design (BBD) was employed to optimize the selected model variables. The optimal extraction conditions were determined: extraction pH of 4.3, extraction temperature of 40 ℃, solid-liquid ratio of 1:27 g/mL, and ultrasonication time of 48 min. UET extracts were compared with other extracts, and it was proved that UET extracts had higher alkaloid extraction rate, comprehensive evaluation value (CEV) and lower energy consumption and CO₂ emission. Then scanning electron microscopy (SEM), dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to explore the extraction mechanism of UET extraction. In addition, UET extraction has more excellent anti-inflammatory activity. The establishment of UET method of CR provides a method reference for green and efficient extraction of alkaloid components from natural drugs.