The optimization of ultrasonic-microwave assisted synergistic extraction of Lotus plumule extract rich in flavonoids and its hypoglycemic activity

Abstract Lotus ( Nelumbo nucifera Gaertn), a kind of perennial aquatic plant, is widely cultivated and consumed by people in Asian countries. plumule flavonoids (LPF) have been recognized as hypoglycemic agent. LPF was optimally obtained using novel ultrasonic-microwave assisted synergistic extraction (UMSE) method response surface methodology (RSM) on the basis results single-factor experiments. Furthermore, activity investigated measuring body weight, fasting blood glucose (FBG) level, oral tolerance test (OGTT) analyzing physiological indexes streptozotocin-diabetic mice model. The optimum conditions consisted microwave power 355 W, ultrasonic 423 time 15 min, solid-liquid ratio 1:40, ultrasound/interval 1/0, ethanol concentration 70% with maximum yield 2.62%. supplementation significantly decreased FBG, OGTT, serum total cholesterol (TC), triglycerides (TG), insulin levels, indicating antidiabetic LPF. This research verified that UMSE technique highly efficient to extract extent from L. exhibited activity, which showed broad development application prospects.