C.N. Esomchi, Uchewa O. Obinna, Ibegbu O. Augustine, Ovuta Adaeze, Uduma I. Marvelous, Joy Onyinye Nwofia, Adaeze Maryann Chukwu, Ogugua Augustine Egwu, Naomi Chinedum Agha
Background Diabetes mellitus remains a global health challenge characterised by oxidative stress, metabolic dysfunction, and tissue injury. Natural products are increasingly investigated as alternative therapies due to their antioxidant and protective properties. Irvingia gabonensis seeds are traditionally used in West Africa to manage various ailments, but their ameliorative potential in diabetes has not been fully explored. Objective This study evaluated the ameliorative effects of aqueous seed extract of Irvingia gabonensis on biochemical, haematological, and histological alterations in streptozotocin (STZ)-induced diabetic male Wistar rats. Methods Thirty male rats were divided into five groups (n = 6). Diabetes was induced by a single intraperitoneal injection of STZ (55 mg/kg body weight) dissolved in freshly prepared cold citrate buffer (pH 4.5). The extract was administered orally at graded doses (100, 200 and 300 mg/kg) for 21 days. Serum glucose, oxidative stress markers, haematological indices, and histology of the liver, spleen, thymus, and bone marrow were assessed. Data were analysed using ANOVA, with p < 0.05 considered significant. Results I. gabonensis at 100 mg/kg reduced blood glucose (238.60 ± 41.57 mg/dL) and preserved pancreatic acinar structures. In comparison, the extract improved body weight, spleen weight, and liver histology. It mitigated oxidative stress, normalised lymphocytes, and protected lymphoid organs. Histological examination revealed that the extract-treated groups showed improved lymphoid architecture, with reduced necrosis and vascular congestion, compared to untreated diabetic controls. However, these changes are dose-dependent. Conclusions Aqueous seed extract of I. gabonensis exhibits dose-dependent ameliorative effects against STZ-induced diabetes-related damage in Wistar rats, suggesting its therapeutic potential in diabetes management.