Tối ưu hóa quy trình ly trích cao chiết lá xạ đen (Celastrus hindsii) giàu polyphenol, flavonoid có hoạt tính kháng oxy hóa và kháng đái tháo đường in vitro

The surveys were arranged based on the response surface methodology according to the Box-Behnken model in Design Expert 11.0 software to optimize the extraction conditions to maximize the total polyphenol and flavonoid content from the leaves of the Celastrus hindsii(CH). The study has extracted polyphenols (120.30±1.15 mg GAE/g extract) and flavonoids (302.39±1.78 mg QE/g extract) optimally by immersion method in ethanol 69% (v/v) 6 hours, material/solvent ratio 1/36 (w/v) and extraction temperature at 60°C. The polyphenol-rich and flavonoid-rich extracts were then studied for their antioxidant and antidiabetic activities in vitro. The results showed that, CH leaf extract exhibited potent neutralizing and reducing activities of free radicals in the test: DPPH (EC50=26.73±1.16 µg/mL), NO• (EC50=55.43±0.78 µg/mL), ABTS•+ (EC50=7.79±0.01 µg/mL), RP (EC50=9.03±0.12 µg/mL), FRAP (EC50=9.20±0.30 µg/mL), and TAC (EC50=59.49±2.61 µg/mL). The CH leaf extract also significantly inhibited α-amylase and α-glucosidase enzyme activities with EC50 values of 156.03±0.43 μg/mL, 26.33±0.76 μg/mL, respectively. This study shows that CH leaf extract, rich in polyphenols and flavonoids, is a promising antioxidant and antidiabetic in vitro agent.