The effect of aminoguanidine, nicorandil and their combination against oxidative stress in
streptozotocin (STZ) - induced diabetes mellitus was assessed in rats by determining changes in
blood glucose level, superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH),
malondialdehyde (MDA) and nitric oxide (NO) in healthy and experimentally induced diabetic rats.
Besides, histhopathological examination of kidney and liver tissues was performed. Diabetic rats
were randomized into groups of six rats and received 50mg/kg, intraperitoneally of aminoguanidine
(an anti- advanced glycation end products (AGE) which prevents the formation of reactive oxygen
species and lipid peroxidation in cells), 0.1mg/kg, orally of nicorandil (nicotinamide derivative
which is efficacious in the treatment of hypertension and angina pectoris and a potassium channel
opener) and their combination once daily for one month. Blood glucose level was significantly
elevated in plasma of diabetic rats. SOD, CAT and GSH levels were significantly reduced, while
MDA and NO levels were significantly elevated in plasma of diabetic rats. Abnormalities in both
kidney and liver structures of diabetic rats were observed. Treatments of the diabetic rats with
aminoguanidine, nicorandil and their combination led to improvement of the abnormalities in SOD,
CAT, GSH, MDA, NO and also the histhopathological abnormalities of kidney and liver. From
these results it can be concluded that aminoguanidine, nicorandil and their combination have the
ability to attenuate oxidative stress induced by streptozotocin. This effect is positively correlated
with their anti-oxidant activities.