Optimization of ultrasonic-assisted extraction and biological activities of total polyphenols from Toona sinensis using response surface methodology

The ultrasound-assisted extraction process of total polyphenols from Toona sinensis (T sinensis) was optimized, and the biological activities of the extracted total polyphenols were studied in vitro. A Box-Behnken design of response surface methodology was employed to further optimize ultrasonic-assisted extraction (UAE) conditions for T sinensis total polyphenols (TSTP). The results showed that optimized extraction conditions were ultrasonic power of 200 W, liquid-solid ratio of 50 mL/g, ultrasonic temperature of 60 degrees C, and ultrasonic time of 22 min. Under these conditions, the mean experimental value of extraction yield (8.13%) was achieved, which was about 49.44% higher than that of distilled water leaching extraction. As compared to TSTP, TSTP after purification (TSPTP) had higher purity of 57.70%, which was nearly 45.33% higher than that of TSTP (12.37%). TSPTP had higher alpha-glucosidase and alpha-amylase inhibitory activities as well as DPPH. and ABTS. +/- scavenging activities with an IC50 value of 0.201, 0.041, 0.27, and 0.07 mg/mL. TSPTP extracted from T sinensis can be used as a multifunctional bioactive ingredient in the formulation of hypoglycemic drugs and antioxidants.