Functional Bread From Bambara Groundnut and Orange Peel Attenuates Hyperglycemia and Oxidative Stress in a High‐Fat Diet/Streptozotocin‐Induced Type 2 Diabetes Rat Model

Abstract

ABSTRACT Dietary interventions represent a promising approach for managing type 2 diabetes mellitus. This study investigated the antihyperglycemic and antioxidant effects of composite bread formulated from Bambara groundnut (BG) and wheat flour blends (0%–75% BG), fortified with orange peel powder, in a high‐fat diet/streptozotocin (HFD/STZ)‐induced diabetic rat model. Over a 14‐day feeding period, rats fed BG‐based composite bread showed significant improvements in blood glucose regulation, enzyme inhibition, and oxidative stress markers compared with untreated diabetic controls. Diabetic rats initially showed elevated blood glucose levels, increased activities of α‐glucosidase, α‐amylase, and lipase, alongside reduced antioxidant enzyme activities and increased lipid peroxidation. However, rats fed BG bread, particularly those on 50% and 75% BG formulations, showed notable reductions in digestive enzyme activities and blood glucose levels, alongside increased activities of key antioxidant enzymes in the pancreas, including superoxide dismutase, catalase, glutathione peroxidase, and glutathione transferase. Additionally, these diets restored nonenzymatic antioxidants, such as reduced glutathione and thiol groups, and significantly reduced reactive oxygen species, indicating reduced oxidative stress. Among all tested formulations, the 75BG bread demonstrated the most potent therapeutic benefits, surpassing even the standard drug acarbose in several parameters. The observed effects are attributed to the rich phenolic content of Bambara groundnut and orange peels, which act synergistically to regulate carbohydrate and lipid metabolism and bolster antioxidant defense. These findings highlight the potential of BG‐based functional foods in managing type 2 diabetes mellitus and underscore the need for further clinical research to support their application in both dietary and pharmaceutical contexts.