Investigating the Preventive Effect of Garlic on Blood Glucose Levels and Histopathology of Pancreas in Streptozotocin-induced Diabetic Rats

The preventive antidiabetic effects of garlic juice on blood glucose levels and pancreas tissue was evaluated in STZ-induced diabetic rats. 40 male rats were divided into five groups of 8 rats each. 1) Normal group (N), 2) Normal+Garlic group (N+G) received 1 ml garlic juice/100g BW/day for 6 weeks, 3) Diabetic group (D) injected with streptozotocin (60 mg/kg BW,i.p.), 4) Diabetic + Garlic_before group (D+Gb) received garlic juice for 6 weeks, but at the end of third week, they were injected with STZ, 5) Diabetic+Garlic_after group (D+Ga) received garlic juice for 3 weeks, after they were injected with STZ. At the end of the experiment, serial sections of pancreas were prepared and stained with H&E for light microscope investigations. Serum glucose levels were significantly increased (p<0.05) in D group in comparison with other groups. There was no significant difference between D+Gb group and N and N+G groups. Body, pancreas, and relative weights was significantly decreased (p<0.05) in D group in comparison with other groups. In D+Gb and D+Ga groups pancreas weight showed no significant difference with the normal group. In D group decrease of pancreatic islet numbers and their mean diameter, atrophy and vacuolation in parenchyma of pancreatic islets were detected. These abnormal histological signs were dramatically decreased in D+Gb group compared to D group. In D+Ga group, dramatical but slighter effects of garlic juice on the histopathological changes of the pancreas were observed. Based on these results, it is thought that garlic juice has favorable effects in preventing changes in blood glucose levels, body and pancreas weights, and the histopathological changes in pancreas in STZ-induced diabetes.