The Effects of Origanum Majorana on Oxidative Stress and Histopathology of Renal Tissue among Streptozotocin-Induced Diabetic Rats

Diabetes type 1 has a variety of destructive effects on different parts of the body including kidney tissue. Diabetic nephropathy is among the serious complications of diabetes. Oxidative stress plays a central role in the development of diabetic nephropathy with glomeruli dilation. Due to the known anti-oxidant and anti-diabetic effects of Origanum majorana (OM), this study was conducted to survey its effects on oxidative stress and histopathology of renal tissue among diabetic rats. In this experimental investigation, 32 male rats, weighing 200 - 250 g, were divided into four groups: 1: control, 2: control receiving treatment with OM, 3: diabetic, and 4: diabetic receiving treatment with OM. Diabetes was induced by intraperitoneal injection of streptozotocin (60 mg/kg). Groups under treatment received food containing 6.25% of OM. Tissue levels of malondialdehyde (MDA) were measured to evaluate the oxidative stress. In addition, renal histopathology was evaluated using hematoxylin and eosin (H & E) staining. Data were analyzed using ANOVA. A significant increase in the renal tissue level of MDA was observed in diabetic and OM-treated diabetic groups versus control group (P = 0.01 and P = 0.04, respectively). OM treatment non-significantly reduced the tissue level of MDA (P = 0.11). Also, diabetes caused a significant increase in glomerular size compared to the control group (P = 0.03), and treatment of diabetic rats with OM caused a non-significant decrease in glomerular size compared to the diabetic group (P = 0.17). Taken together, long term treatment of diabetic rats with OM can partially protect the renal tissue via attenuation of oxidative stress and glomerular expansion.