الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 152 |  |  |
| | | from | 152 | | |
Abstract
This experiment was aimed to assess the protective influences of Stevia extract as ant diabetic and antioxidant agents on the expressions of antioxidant signaling pathway and glucose uptake in kidney and evaluate the possible protective effects of stevia extract on diabetic nephropathy in male rats. The potential outcome is probably a cheap, simple, and safe approach curbing the spread of type 2 diabetes.Animals and experimental design:Prior to the experiment, 36 male albino rats weighing (110 ±5 g per each) were housed in the animal facility of the Zoology, Department Faculty of Science, Mansoura University separately in stainless steel cages for two weeks to acclimatization. The cages were kept at a constant temperature of 22°C and had 12-hour illumination cycles. Additionally, food and water are constantly available to them. All rats were treated, in line with the principles of Institutional Animal Ethics.18 rats were kept as normal control and the other 18 were prepared to induce diabetic. Streptozotocin (STZ) at a dose of 55 mg/kg body weight was used to induce diabetes. After 15 minutes, the rats received an injection of nicotinamide (NA) at a dose of 100 mg/kg body weight, which served to partially protect the pancreatic beta cells from STZ, (prepared in fresh in 0.1 M citrate buffer pH 6.3), then were confirmed diabetic by withdrew blood from the tail vein, to examine the fasting glucose (FBS) in blood having blood glucose more than 300 mg/dl after 72 hr of injection.The experimental rats comprised the following four groups:1-group 1: 9 rats didn’t receive any treatment, served as normal control.2-group 2: 9 diabetic rats didn’t receive any treatment, served as positive control.3-group 3: 9 rats receive stevia extract at 400 mg/kg through gastric oral gavages.4-group 4: 9 diabetic rats receive stevia extract at 400 mg/kg through gastric oral gavages.The treatment was performed each morning over 30 days.Results of the present study can be summarized in the following points:Body weight:-It was found no significant differences between all groups in initial body weight in the beginning of the experiment.-The final body weight in stevia group was significantly elevated as compared to the diabetic group rats.-Diabetic group oral administration with stevia extract increased the body weight comparing to the diabetic group.-When diabetic group oral administration with stevia extract showed improving in body weight% compared to the diabetic group.-The diabetic group scored a significant increase in kidney weight over the control, but diabetic+stevia group decreased the kidney weight comparing to the diabetic group.Serum parameters:-In diabetic group rats a significant increase was happened in serum glucose level over the control group, then diabetic+stevia group rats recorded a significant decrease comparing to the diabetic group rats.-In diabetic+stevia group increase the serum insulin level comparing to the diabetic group.-Diabetic group oral administration with stevia extract, the serum creatinine level (mg/dl) decreased significantly compared to the diabetic group.-Administration of 400 mg/kg of stevia extract to diabetic rats during the experiment showed a significant reduction in the serum urea level comparing to the diabetic group.-Treatment of diabetic rats with stevia extract (400 mg/kg) caused a significant decrease in the serum uric acid (P < 0.05) in comparison to diabetic group rats.-The stevia extract (400 mg/kg) significantly increase the mean serum total protein level in diabetic rats compared to the diabetic control.-The rats treated with stevia extract showed a significant increase in the mean glutathione peroxidase activity level (GSH) compared to the diabetic control group.-Serum malondialdehyde (MDA) recorded a significant reduction in stevia diabetic group comparing to the diabetic group.Tissue parameters:-In stevia+diabetic group, IL-1β level was markedly increase, but still higher than that of the control group and decreased comparing to diabetic control.-Oral administration with stevia in diabetic group reduced the level of IL-6 under the diabetic group.-Oral administration with stevia extract (400 mg/kg) in diabetic group reduce the TNF-α (pg/ml protein) compared to the diabetic group.-Diabetic + stevia group recorded a significant reduction in tissue caspase-3 (pg/mg protein) level comparing to the diabetic control.-Caspase-8 (pg/mg protein) level with diabetic group administered stevia significantly was decrease comparing to the diabetic group.-Administration of stevia extracts 400 mg/kg orally to diabetic rats during the experiment showed a significant decrease in cyt-c level (1.17 ng/mg) comparing to the diabetic group.-Administration of (400 mg/kg) stevia extract orally during the experiment significantly increase the level of p53 in kidney tissue comparing to the diabetic group.-Daily treatment of diabetic rats with 400 mg/kg stevia extract orally during the experiment produced a significant decrease in the kidney tissue Bax level in comparison to diabetic group rats.-Orally administration of 400 mg/kg stevia extract led to increase the Bcl-2 in kidney tissue comparing to the diabetic group.Serum electrolytes regulate:-Orally administration with 400 mg/kg of stevia extract to diabetic group increased the level of Na in serum comparing to the diabetic group.-Daily treatment of diabetic rats with 400 mg/kg stevia extract orally during the experiment produced a significant decrease in the serum Ca level in comparison to diabetic rats.-Orally administration with 400 mg/kg of stevia extract to diabetic group increased the level of K in serum comparing to the diabetic group.-Daily treatment of diabetic rats with 400 mg/kg stevia extract orally during the experiment produced a significant increase in the serum Mg level in comparison to diabetic rats.Urine parameters:-Administration of stevia extracts 400 mg/kg orally to diabetic rats during the experiment showed a significant decrease in NGAL level (comparing to the diabetic group.-Administration of 400mg/kg stevia extract orally to rats produced a significant decrease in the urine KIM-1 level comparing to diabetic group.-Daily treatment of diabetic rats with 400 mg/kg stevia extract orally during the experiment produced a significant decrease in the urine total protein in comparison to diabetic group rats.© Conclusion:We demonstrated that stevia extract protected diabetic rats against renal injury. We further demonstrated that stevia extract possessed anti-oxidant and anti-inflammatory properties after renal injury in diabetic rats, which might be mediated via the modulation of oxidative stress, inhibition of TNF- α-stimulated inflammation. These findings suggest the potential role of stevia extract against renal injury in diabetic patients. Therefore, it could be concluded that study data support the use of stevia extract (400 mg/kg/daily) to reduce the problems associated with type 2 diabetes.