Alleviation of oxidative stress-mediated nephropathy by dietary fenugreek (Trigonella foenum-graecum) seeds and onion (Allium cepa) in streptozotocin-induced diabetic rats

Oxidative stress plays a major role in the progression of diabetes and the pathogenesis of diabetic nephropathy. In this study, the beneficial influence of dietary fenugreek (Trigonella foenum-graecum) seeds and onion (Allium cepa) on oxidative stress-mediated renal injury was evaluated in streptozotocin-induced diabetic rats. Diabetes was induced in adult Wistar rats by the administration of streptozotocin (i. p. 45 mg kg(-1)). Dietary interventions were made with 10% fenugreek seeds or 3% onion (freeze-dried) or their combination for 6 weeks. These dietary interventions countered nephromegaly in the diabetic animals, the increase in creatinine clearance and oxidative stress in renal tissue. These dietary interventions significantly countered the increased renal cholesterol and triglycerides associated with the diabetic condition. The up-regulation of the receptor for advanced glycation end products, inflammatory cytokines and oxidative stress markers in the renal tissue of the diabetic rats was effectively countered. Renal 8-hydroxy-2deoxyguanosine, its excretion, DNA fragmentation and mitochondrial DNA deletion were significantly annulled in the diabetic rats by these dietary interventions. Generally, the beneficial effects were greater in the combined intervention, although they were not additive. Thus, the beneficial influence of dietary fenugreek and onion on oxidative stress-mediated renal injury is higher when consumed together and this may be a strategy to ameliorate diabetic nephropathy.