Optimization of ultrasonic assisted extraction and biological activity of total flavonoids from Ligusticum chuanxiong Hort. using response surface methodology

The purpose of this research is to study the optimization of the extraction process of total flavonoids from Ligusticum chuanxiong and its biological activity. The flavonoid components of Chuanxiong (LCTF) were extracted by ultrasonic assisted method and optimized by response surface methodology to determine the best extraction process. The obtained total flavonoid extracts were purified by AB-8 macroporous resin, and their hypoglycaemic levels and antioxidant levels were determined. The optimal conditions were as follows: ethanol concentration of 72%, extraction time of 61 min, liquid-solid ratio of 28 mL/g, extraction temperature of 40 celcius and ultrasonic power of 320 W. The yield was (3.07 +/- 0.03) mg/g, compared with (2.22 +/- 0.05) mg/g obtained by conventional water extraction. The purity of total flavonoids of Ligusticum chuanxiong after purification (LCPTF) was 6.36%, which was 2.3 times higher than that of LCTF. The IC50 values of LCPTF for alpha-glucosidase, alpha-amylase, DPPH and ABTS assays were 0.024 mg/mL, 0.677 mg/mL, 0.232 mg/mL and 0.317 mg/mL, respectively. and the overall inhibition rates were positively correlated with the concentrations. The total flavonoids of Ligusticum chuanxiong exhibited high levels of inhibition of alpha-glucosidase, alpha-amylase, DPPH radicals and ABTS radicals, and the activity levels were further increased after purification, which had certain reference significance for the development and application of products related to the total flavonoids of Ligusticum chuanxiong.