Stereological Estimation of Volumes of Islet of Langerhans in Diabetic Wistar Rats Treated with Tectonia Grandis (Teak) Leaves

In this study we evaluated the changes in the pancreatic islet volume of diabetic rats following treatment with aqueous extract of Tectona grandis (teak) leaves. 25 apparently healthy young male Wistar rats divided into five (5) groups (normal control, diabetic control and three treatment groups) were used for the study. Diabetes was induced via high fat diet feeding for 10 weeks followed by streptozotocin injections (40mg/kg bwt). A normal control group was administered distilled water 1 ml/kg bwt. A diabetic group was administered normal saline 1ml/kg bwt, another group was treated with metformin 500mg/kg bwt. The last two groups were treated with high and low dose of the extract at 200mg/kg bwt and 100mg/kg bwt respectively. Treatment lasted for 35 days via oral route. Pancreatic tissue samples were collected after anesthesia/dissection and fixed in neutral buffered formal saline. Isotropic uniform random sections were obtained via the orientator method. Serial sections were cut with a rotatory microtome and stained with H & E. Pancreatic islet volumes were measured using the cavalieri estimator grid. The result showed increase in the volumes of pancreatic islets of the treated groups which was statistically significant when compared to the normal control. However, when compared to the diabetic and metformin control groups, the increases in the pancreatic islet volumes was seen not to be statististically significant.

Key Words: type 2 diabetes mellitus, volume estimation, stereology, pancreatic islets