Optimization of Microwave Extraction of Total Flavonoids from Moringa Leaves by Response Surface Methodology. The ethanol concentration, microwave power, extraction time and liquid-to-material ratio were selected as the influencing factors, and the total flavonoid yield was the evaluation index. On the basis of single factor experiment, the quadratic polynomial regression equation of flavonoid yield was established by the combination of 4 factors and 3 levels Box-Behnken center to study the effect of the above factors on the yield of total flavonoids. The results showed that the optimum extraction conditions were as follows: ethanol concentration 58%, microwave power 397 W, extraction time 8 min, liquid to material ratio 59:1. Under this condition, the total flavonoid yield was 3.45%, which was basically consistent with the expectation. HepG2 cells were used to study the hypoglycemic effect of total flavonoids from Moringa oleifera L., and the glucose uptake of the cells was measured for 24 h. The results showed that the total flavonoids of Moringa oleifera L. could promote the consumption of glucose in HepG2 cells under high glucose environment. Under the same concentration, the hypoglycemic activity of total flavonoids extracted by microwave was stronger than that obtained by reflux extraction.