Effect of fenugreek, onion and garlic on blood glucose and histopathology of pancreas of alloxan-induced diabetic rats

Abstract

Many traditional treatments have been recommended in the alternative system of medicine for treatment of diabetes mellitus; however, the mechanism of most of the herbals used has not been defined. This study was carried out to clarify the effect of fenugreek, garlic and onion, recommended in Persian folklore medicine as beneficial in the treatment of diabetes, on blood glucose and their possible effect on pancreatic tissue. Diabetes mellitus was induced in 20 out of 25 adult male albino rats, using intraperitoneal injection of 185 mg/kg BW alloxan. The diabetic rats were divided into four groups, three of which were fed a diet containing 12.5% BW Allium sativum (garlic), Allium cepa (onion) or Trigonella foenum-graecum (fenugreek) for 15 days. The fourth group (positive control) received an ordinary diet. The remaining non-diabetic rats (negative control group) received neither alloxan nor the mentioned plants. Following consumption of plants, blood glucose was measured every day and on the last day the pancreas were removed and stained with H&E and Gomeri aldehyde fuchsin (GAF). Morphology of the pancreatic sections and the following morphometric factors were studied: volume density of B cells, volume density of islets, percent of B cells, number of islets per square millimeter, average area of islets and average volume density of B cell in whole pancreas. One-way Analysis of Variance (ANOVA) test and Duncan's multiple range tests were used to evaluate the data. The results of this study indicate that only garlic was able to reduce blood glucose significantly compared with the control group (P<0.05). In the control positive group all the mentioned morphometric factors were significantly changed in comparison with the control negative (normal health) group, but the same did not show significant change between treated and untreated diabetics.