Gastrodin ameliorates diabetic nephropathy by activating the AMPK/Nrf2 pathway

Diabetic nephropathy (DN) is a leading cause of end-stage kidney failure, contributing to elevated morbidity and mortality rates in individuals with diabetes. Despite its potential renoprotective effects, the molecular mechanism by which gastrodin (GSTD) impacts DN remains unclear. To investigate this, mice were initially induced with DN via intraperitoneal streptozotocin (STZ) injection (50 mg/kg) and subsequently treated with varying doses of GSTD (5, 10, 20 mg/kg). Furthermore, the potential molecular mechanism of GSTD in mitigating DN was explored in vivo in conjunction with compound C, an inhibitor of 5'-AMP-activated protein kinase (AMPK). Subsequently, the blood weight, fasting blood glucose levels, and renal injury markers of DN-afflicted mice were assessed. Additionally, renal tissues were subjected to quantitative reverse-transcriptase-polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) to evaluate inflammatory factor levels, colorimetric assays to measure renal malondialdehyde (MDA) levels, and immunoblotting analysis to examine AMPK/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. The results demonstrated that a 6-week GSTD regimen effectively improved metabolic manifestations associated with DN, including reductions in fasting blood glucose levels, 24-hour urine output, renal indices, amelioration of glomerular histopathological abnormalities, diminished glycogen accumulation, and fibrosis. Furthermore, DN-afflicted renal tissues exhibited decreased MDA levels and elevated expression of AMPK/Nrf2 pathway-associated proteins. The beneficial effects of GSTD on DN and its protein modulation were reversed upon co-intervention with compound C. Together, our findings imply that GSTD improves DN by activating the AMPK/Nrf2 pathway, thereby mitigating STZ-induced renal damage, inflammatory responses, and oxidative stress.