Ultrasonic-assisted extraction and biological activities of traditional Chinese/Mongolian medical herb Artemisia ordosica Krasch. using natural deep eutectic solvents

• NADES showed better extraction performance than traditional organic solvents. • Bet-EG was screened out for extraction polyphenol and flavonoid compounds from AOK. • Bet-EG extract showed better biological activity property than traditional solvents. • The yields of TPC and TFC optimized by RSM were 16.234 and 44.528 mg/g, respectively. To fully exploit the medicinal potential of Artemisia ordosica Krasch. (AOK) in traditional Chinese/Mongolian medicine, we identified betaine-ethylene glycol (Bet-EG), an outstanding high-performance natural deep eutectic solvent (NADES), and applied it in conjunction with ultrasonic-assisted extraction to obtain polyphenolic and flavonoid bioactive constituents. Both one-way and response surface multifactorial approaches were used to investigate the effect of NADES composition and ultrasonic extraction parameters, including time, power, temperature, and liquid–solid ratio of AOK. Box-Behnken experimental design revealed optimal extraction parameters for total phenol content (TPC) and total flavonoid content (TFC): 2.10 h extraction time at 40 °C, with a 154 mL/g solvent/solid ratio, accompanied by water contents of 8.60 wt% and 8.00 wt%, respectively. Under these optimized conditions, the extraction efficiencies of TPC and TFC reached 16.234 ± 0.675 mg GAE/g and 44.528 ± 0.833 mg RE/g, respectively, representing 3.059- and 4.171-fold increases compared to conventional water extraction. The underlying mechanism was successfully modeled and validated through second-order kinetics. Comparative analyses demonstrated Bet-EG’s superior performance over conventional solvents in both polyphenol/flavonoid recovery and bioactivity preservation, specifically regarding antioxidant capacity and mast cell-stabilizing effects. FE-SEM analysis further revealed the solvent’s enhancement effect and influence by Bet-EG through the extraction process. In conclusion, the present study established a straightforward, efficient, sustainable protocol for extracting polyphenols and flavonoids from AOK. This method warrants further investigation for industrial scale-up in the pharmaceutical and cosmetic fields.