Ultrasound-Assisted Sustainable Extraction of Berberine from Coptis chinensis Franch. Using Temperature-Responsive Deep Eutectic Solvents

Abstract The development of deep eutectic solvents (DESs) that can be readily and sustainably recycled is expected to reduce costs and enhance the environmental friendliness of extracting plant-derived active ingredients. Here, a novel temperature-responsive DES prepared from propylene carbonate and n-butanol was employed as the extractant for ultrasound-assisted extraction of berberine from Coptis chinensis Franch. The prepared temperature-responsive DES did not require the addition of acids, bases, or salts. Phase separation between DES and water was achieved under mild conditions simply by adjusting the temperature. At 45 °C, DES and water formed a single phase and were used for berberine extraction. Upon decreasing the temperature to 25 °C, the DES phase separated from the aqueous phase, enabling recovery of DES and berberine. The relatively low critical solution temperature (45 °C) of DES enabled mild extraction conditions, minimizing the thermal degradation of active components. The recovered DES was reused for subsequent extractions; after five cycles, the yield showed no decrease, while berberine recovery remained above 80%. Moreover, the biological activity of the berberine extract was assessed, revealing its efficacy in suppressing the lipopolysaccharide-induced inflammatory response in RAW264.7 cells and inhibiting the proliferation of gastric cancer cells. Furthermore, network pharmacology analysis suggested that berberine may exert antigastric cancer activity by regulating the cell cycle. Overall, this study presents a green and sustainable strategy for berberine extraction and provides a promising basis for its potential application in gastric cancer therapy.