Ameliorative Effect of Aqueous Extracts of Seeds of Delonix regia (Hook) Raf on the Liver, Kidney and Spleen of High-fat Diet Streptozotocin-induced Diabetes in Female Wistar Rats

Abstract

Background: Plants have been relied upon by people for treatment, control and management of diabetes. The local residents around University of Port Harcourt, Nigeria, use cooked Delonix regia (Hook.) Raf. Seeds as food supplement for the management of diabetes. Aim: Based on the available evidence on this plant species, this study was carried out to evaluate the ameliorative potentials of aqueous cooked and uncooked seed extracts of Delonix regia (Hook.) Raf. On the liver, kidney and spleen of high-fat diet streptozotocin-induced diabetes in female Wistar rats. Methods: Forty-eight rats were grouped into eight. Group 1 served as normal control and was fed with normal diet. The diabetic state was achieved by feeding the rats with high-fat diet which contained 20% sucrose, 20% lard and 60% grower mash for six weeks, followed by 40 mg/kg body weight of a single dose intraperitoneal injection of streptozotocin. Seven days after induction of diabetes, rats in group 2 did not receive any treatment and were designated as the negative control. Rats in groups 3 (Positive control) and 4 (Second positive control) received metformin 100mg/kg and metformin/vildagliptin 50/25 mg/kg body weight respectively as standard drugs while groups 5 to 8 designated (A1), (A2) (B1) and (B2) respectively, were induced and treated daily with 150 and 300 mg/kg body weight orally cooked seeds (A1), (A2) and uncooked seeds (B1), (B2) extracts for six weeks. Blood was obtained through cardiac puncture after the rats were anaesthetised and sacrificed. Histopathology of the liver, kidney and spleen were studied. Results: Both extracts significantly (p<0.05) decreased the bilirubin, potassium, bicarbonate concentrations, alkaline phosphatase (ALP) and alanine transaminase (ALT) activities as well as granulocyte count in dose and time-dependent manner when compared to group 2 respectively. Photomicrographs of the spleen of diabetic untreated rats showed significant hemosiderin pigment deposition compared to the splenic architecture of the normal rats. Treatment with Delonix regia (Hook.) Raf extracts prevented hemosiderin pigment deposition in groups 5 to 8.  Conclusion: This study, therefore, provides useful resources about the ameliorative potentials of seed extracts of Delonix regia (Hook.) Raf. on streptozotocin-induced diabetes in female Wistar rats.