Cardioprotective effects of Anthocephalus cadamba bark extract and pyridoxine in STZ-induced diabetic rats

Abstract

Background: Oxidative stress driven by hyperglycaemia and hyperlipidaemia plays a major role in diabetic cardiomyopathy. Although Anthocephalus cadamba bark and pyridoxine have traditional uses, their combined efficacy against diabetic cardiomyopathy remains underexplored. In this work, streptozotocin (STZ)-induced type 2 diabetic rats were used to investigate the preventive benefits of an ethanolic bark extract of A. cadamba given either with or without pyridoxine. Methods: Diabetes was induced in Wistar rats with STZ (45 mg/kg, i.p.). Animals were allocated to eight groups and treated with metformin, A. cadamba extract (200 or 400 mg/kg), pyridoxine (100 mg/kg), or combinations of these agents for eight weeks. Biochemical markers (CK-MB, LDH, AST), lipid profile, and oxidative stress enzymes were assessed, along with heart histopathology. Results: Diabetic rats showed marked elevations in CK-MB, LDH, and AST, which were significantly reduced by A. cadamba (200–400 mg/kg) (e.g., CK-MB, LDH, and AST decreased by approximately 25-33%). (p < 0.001). Combining pyridoxine with other therapies produced the strongest effect, lowering CK-MB, LDH, and AST by 30–41% (p < 0.001). Treatment with A. cadamba extract alone and in combination with pyridoxine significantly improved dyslipidaemia, with HDL rising from ~42 to 52% (p < 0.01-0.001) and decreasing serum-lipoproteins concentration (total Cholesterol, triglyceride, LDL, and VLDL) by ~40 to 55% (p < 0.01). Antioxidant defenses were also restored, with SOD, CAT, and GSH levels rising by 70–80% (p < 0.05–0.001). Histology confirmed reduced necrosis and fibre degeneration, most notably in the combination-treated groups. Conclusion: A. cadamba extract and pyridoxine, particularly in combination, mitigate oxidative stress, hyperlipidaemia, and cardiac injury in STZ-induced diabetic rats, suggesting therapeutic potential against diabetic cardiomyopathy.