Zygophyllum album has been mentioned in Tunisian system of traditional medicine to be of value in the treatment of diabetes mellitus. The aqueous extract from Zygophyllum album were examined for relaxant effects in isolated mice thoracic aorta, Nitric Oxide (N0) spin-trapping technique combined with Electron Paramagnetic Resonance (EPR) spectroscopy has been employed to measure the ex vivo production of NO in liver, heart, pancreas and aorta. The antihyperglycemic effects of aqueous extract from Zygophyllum album (100 and 300 mg/kg bw) during 15 days on important enzymes of carbohydrate metabolism in livers of non- diabetic and streptozotocin-induced diabetic mice was evaluated. Administration of the aqueous extract plant (100 and 300 mg/kg bw) for 15 days resulted in significant reduction in hepatic Glucokinase (GK), glycogen in STZ diabetic mice. In addition to that, significant increase in hepatic Phosphofructokinase (PFK), Glucose-6 Phosphate Dehydrogenase (G6PDH) observed in STZ diabetic mice.