Anti-diabetic and Histopathological Effects of Aqueous Leaf Extract of <i>Sterculia tragacantha</i> on Pancreas of Alloxan-Induced Diabetic Male Sprague-Dawley Rats

Abstract

Diabetes mellitus, a long-term disease of glucose metabolism, is usually marked with hyperglycaemia, and often leads to severe complications despite the use of conventional anti-diabetic medications. This study investigated the anti-diabetic potential and histopathological effects of aqueous leaf extract of Sterculia tragacantha on the pancreas of alloxan-induced diabetic male Sprague-Dawley rats. Sixty-two male rats (150–180 g) were used. The acute toxicity testing (LD₅₀) was determined using modified Lorke’s method with 32 rats comprising eight groups (n=4) receiving single oral doses of the extract at 100, 200, 300, 400, 500, 1000, 3000, and 5000 mg/kg, respectively. The 100 mg/kg served as the control. Another thirty rats, divided into six groups (n=5): negative control, diabetic-untreated (disease control), glibenclamide-treated (5mg/kg), and three extract-treated (44.72, 89.44, and 134.16 mg/kg); were administered orally, once daily for 14 days after diabetes induction with 150mg/kg alloxan (single intraperitoneal injection). Body weight and fasting blood sugar (FBS) were measured at baseline, 24 hours, 7 and 14 days post-treatment. After sacrifice via the chloroform-inhalation method, pancreas weights were measured, histologically-processed and stained with haematoxylin and eosin, Masson trichrome, and anti-insulin immunohistochemical antibody. The LD₅₀ was 447.21mg/kg. Body and pancreas weights remained unaffected (p=0.511, p=0.103). The extract and glibenclamide significantly reduced FBS on days 7 (p=0.015) and 14 (p=0.001) compared with the disease control. Low-dose group preserved normal pancreatic histology and beta cell number, whereas medium-dose, high-dose, and glibenclamide-treated groups showed islet atrophy, fibrosis, and beta cell loss. The low dose of the extract exhibited anti-diabetic activity and is the safest compared with glibenclamide.