Simvastatin mitigates diabetic nephropathy by upregulating farnesoid X receptor and Nrf2/HO-1 signaling and attenuating oxidative stress and inflammation in rats

Diabetic nephropathy is one of the complications of diabetes that affects the kidney and can result in renal failure. The cholesterol-lowering drug simvastatin (SIM) has shown promising effects against diabetic nephropathy (DN). This study evaluated the protective role of SIM on DN, pointing to the involvement of farnesoid X receptor (FXR) and Nrf2/HO-1 signaling in attenuating inflammatory response, oxidative injury, and tissue damage in streptozotocin-induced diabetic rats. SIM was supplemented orally for 8 weeks, and samples were collected for analysis. SIM effectively ameliorated hyperglycemia, kidney hypertrophy, body weight loss, and tissue injury and fibrosis in diabetic animals. SIM mitigated oxidative stress (OS), inflammatory response, and cell death, as evidenced by the suppressed malondialdehyde, nitric oxide, myeloperoxidase, NF-kB, TNF-α, IL-1β, CD68, Bax, and caspase-3 in the diabetic kidney. These effects were linked to suppressed Keap1, upregulated FXR, Nrf2, and HO-1, and enhanced antioxidant defenses and Bcl-2. The in silico findings revealed the binding affinity of SIM with NF-kB, caspase-3, Keap1, HO-1, and FXR. In conclusion, SIM protects against DN by attenuating hyperglycemia, kidney injury, fibrosis, inflammation, and OS, and upregulating antioxidants, FXR, and Nrf2/HO-1 signaling.