Extracts of <i>Hunteria umbellata</i> reverses the effect of streptozotocin‑induced pancreatic islet‑cell destruction

Abstract

The use of extracts of plant parts in the treatment and/or management of diabetes mellitus has formed the basis of health care in most African countries. The aim of this study was to investigate the possible effect of oral administration of extracts Hunteria umbellata (HU) leaves and seeds on streptozotocin- induced pancreatic β-cell damage. Twenty four (24) adult wistar rats were selected into two control group (negative control group A and positive control group B) and two treatment groups (C & D) each containing six animals each (n= 6 per group). Rats in the positive control group (B) were giving intraperitoneal injection of with 50 mg/kg body weight of Streptozotocin (STZ) prepared with 0.05M Citrate buffer solution while the negative control group A rats were injected with a corresponding volume of Citrate buffer without STZ. Rats in the treatment groups were treated with 250 mg/kg body weight aqueous extract of seeds of Hunteria umbellata (group C) and 250 mg/kg body weight aqueous extract of leaves of Hunteria umbellata (group D) respectively. Blood samples were taken by repeated needle puncture of their tail tip vein every 72 hours at the end of a 12 hrs fasting. Fasting blood glucose was determined using a fine test glucometer and compatible glucose test strips. Rats were sacrificed by cervical dislocation on the 15^th day and the pancreas was accessed and dissected out through a midline incision of the anterior abdominal wall of the rats. The pancreas was fixed in 10% buffered formal saline for routine histological examination. 5ml blood samples were collected in heparin coated tubes for serum anti-oxidant estimation. Results obtained showed that HU seeds and leaves extracts significantly (P < 0.05) increased Superoxide dismutase (SOD) and Catalase (CAT) activities and decrease in the activity of Thiobarbituric acid reactive species (TBARS) when compared streptozotocin injected rats. Histological sections showed marked distortion, vacoulation of the central part of the Islet. Treatment with Hunteria umbellata seed and leaf extracts reversed the cytoarchitectural distortion of pancreatic Islet cells caused by Streptozotocin. This suggests that extracts of HU seeds and leaves posses antidiabetic potential.

Keywords: Hunteria umbellata, streptozotocin, pancreatic Islet, cytoarchitectural distortion