This study investigated the antidiabetic effects of purslane (PS), chard (CA), and chicory (CI) leaf powders on streptozotocin (STZ)-induced type 2 diabetic rats. The total polyphenols, flavonoids and polyphenolic profiles were determined in the leaf powders. Thirty adult male albino rats were divided equally into six groups: untreated non-diabetic control was considered negative control. Other rat groups were rendered diabetic (fasting blood glucose (FBG) level >250 mg/dL) with a twice intraperitoneal injection of STZ (35 mg⁄kg). Diabetic rats were fed a basal diet. They were classified into five groups: a diabetic control group (positive control), a group receiving metformin (100 mg/kg body weight) as a medication, and other groups were fed a basal diet supplemented with either PS, CA, or CI leaf powder at a 1% level. The experiment lasted for 40 days. Blood samples were analyzed for FBG, insulin, fructosamine and oral glucose tolerance test (OGTT). Feeding diabetic rats basal diet containing the investigated leaf powders decreased insulin resistance (HOMA-IR,) significantly compared to diabetic rats. The CI and PS leaf powders displayed powerful positive hypoglycemic action compared to metformin, in addition to reversing the histological abnormalities in the liver and pancreas of diabetic rats to a state close to normal. Therefore, the investigated leaves may help reduce the metabolic syndrome associated with type 2 diabetes.