The Nephroprotective Efficacy of Omega-3 Fatty Acids Against Streptozotocin-Induced Diabetic Renal Injury: A Biochemical, Histopathological and Ultrastructural Study

The present study was designed to evaluate the structural and biochemical efficacy of Omega-3 fatty acids in preventing renal injury in streptozotocin (STZ)-induced diabetic kidney injury and to correlate systemic oxidative stress parameters with histological and ultrastructural parameters. Twenty-eight male Wistar Albino rats were randomly divided into four groups (n = 7) as follows: Control, Omega-3 (500 mg/kg, orally), Diabetes Mellitus (DM; 50 mg/kg STZ, i.p.), and DM+Omega-3 (STZ, followed by 500 mg/kg Omega-3 for 42 days). Biochemical analysis of renal function (blood urea nitrogen (BUN) and creatinine) and oxidative status (malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), total antioxidant status (TAS), total oxidant status (TOS) and oxidative stress index (OSI)) was measured by ELISA. Histopathological scoring and Caspase-3 staining were performed by Hematoxylin and Eosin (H&E) and immunohistochemically, respectively. Transmission Electron Microscopy (TEM) was used to examine the renal tissues. Our results showed that the DM group presented with severe hyperglycemia, uremia, and a significant oxidative shift, as evidenced by increased MDA/TOS levels and depleted antioxidant defenses. Light microscopy showed extensive glomerular damage, tubular degeneration and inflammatory infiltration in the kidneys of diabetic rats. Immunohistochemical analysis revealed strong Caspase-3 expression in the tubular and glomerular compartments. TEM showed severe podocyte effacement and damage to the glomerular basement membrane (GBM). Notably, Omega-3 supplementation significantly reversed renal dysfunction, restored the pro-oxidant/antioxidant balance and reduced histopathological injury scores. Moreover, Omega-3 treatment efficiently blocked Caspase-3-mediated apoptotic signaling and preserved the ultrastructural integrity of the glomerular filtration barrier (GFB) and tubular mitochondria. Our results demonstrate the potent nephroprotective effects of Omega-3 fatty acids in reducing oxidative stress, preventing programmed cell death and maintaining the stability of the renal parenchyma’s microarchitecture. These findings suggest that Omega-3 fatty acids could be an effective adjuvant therapeutic agent for the management of diabetic nephropathy.