Pharmacological Study of Flower Bud Extract of Syzygium aromaticum (Clove) in Modulating Weight, Oxidative Stress and Glycaemic Indices in Alloxan-induced Diabetic Rats

Abstract

Syzygium aromaticum is a flowering plant whose dried flower buds (cloves) are widely used as a spice. Aim: This study aims to evaluate the modulatory potentials of aqueous extract of clove on oxidative stress and glycaemic indices of alloxan-induced diabetic Wistar rats. Methodology: Eighty male rats weighing 100-130g were grouped into eight (n=10). NEXC1 served as the normal experimental control. Groups 2-8 were fed a high-fat diet for 28 days and administered a single intraperitoneal injection of 150 mg kg-1 body weight of alloxan to induce diabetes and are designated HFAD2, HFAD3, HFAD4, HFAD5, HFAD6, HFAD7 and HFAD8, respectively. Diabetes was established after three consecutive days of Fasting Blood Sugar measurement between 11 and 13 mmol/L. HFDA2 did not receive any treatment. HFDA3 was treated with 500 mg kg-1 body weight of metformin. HFDA4, HFDA5, HFDA6, HFDA7, and HFDA8 were treated with 500, 1000, 1500, 2000, and 2500 mg kg-1 body weight of the extract, respectively, for 28 days. Biochemical indices and histological examination were assessed. Results: HFDA4, HFDA5, HFDA6, HFDA7 and HFDA showed significant increase (p<0.05) in superoxide dismutase (53.64±3.04 U/ml), catalase (4.87±0.36 U/ml)), with a significant decrease (p>0.05) in glucose (4.00±0.03 mmol/l), amylase (28.72±0.72), nitric oxide (1.13±0.28 ug/L), and glutathione activities (10.27±1.22 nmol/L) when compared to HFAD2. The photomicrographs showed atrophic pancreatic islets and tubular necrosis with discontinuous brush borders of renal cells in HFAD2. However, the treatment groups were ameliorated by different concentrations of the extract, and the tissues were restored to normal. Conclusion: The extract, at 2500 mg kg-1, showed ameliorative effect on glucose, amylase and a reduction in oxidative stress indices and can therefore be harnessed in the management of diabetes.