This study evaluated the antioxidant activity and anti-diabetic effect of mulberry (Morus
albaL.wielkolistna zolwinska) leaf extracts in diabetic rats fed a high-fat diet. After initial
4-week high-fat diet, streptozotocin was injected in Wistar rats to induce non-obese type
2 diabetes. After confirmation of diabetes, animals were treated with mulberry dried leaves,
leaf-derived ethanol or acetone extracts added to high-fat diet for 4 weeks. Mulberry ethanol
extract with higher level of phenolics – chlorogenic acid and flavonol glucosides was more
effective than acetone extract or dry leaves in the lowering of blood glucose, increasing insulin
level and markers of antioxidant activity. The results confirm key mechanisms related to
the effect of mulberry and its bioactive components on modulation of glucose metabolism
through correcting hyperglycaemia, increasing insulin secretion, and improving antioxidant status in STZ-induced non-obese diabetic rat model. Antidiabetic effects exerted by
mulberry leaves might depend on the extraction process.