Background: Acute kidney injury (AKI) is a common clinical condition resulting in a rapid decline in renal function, and requires improvement in effective preventive measures. Ferroptosis, a novel form of cell death, is closely related to AKI. Shenshuaifu granule (SSF) has been demonstrated to prevent AKI through suppressing inflammation and apoptosis.
Objective: This study aimed to explore whether SSF can inhibit ferroptosis in AKI.
Methods: Active ingredients in SSF were detected through HPLC-MS/MS, and their binding abilities with ferroptosis were evaluated by molecular docking. Then, male C57/BL/6J mice were randomly divided into control, cisplatin, and cisplatin+SSF groups. In the latter two groups, mice were intraperitoneally injected with 20 mg/kg of cisplatin. For five consecutive days prior to cisplatin injection, mice in the cisplatin+SSF group were gavaged with 5.2 g/kg of SSF per day.
72 h after cisplatin injection, the mice were sacrificed. Serum creatinine (SCr) and blood urea nitrogen (BUN) were measured to evaluate renal function. H&E and PAS staining were used to observe pathological damage of kidney. Cell death was observed by TUNEL staining, and iron accumulation in kidneys of mice was detected by Prussian blue staining. Western blotting, immunohistochemistry, and immunofluorescence were used to investigate the presence of inflammation, oxidative stress, mitochondrial dysfunction, iron deposition, and lipid peroxidation in mouse kidneys.
Results: Active ingredients in SSF had strong affinities with ferroptosis. SSF reduced SCr (p < 0.01) and BUN (p < 0.0001) levels, pathological damage (p < 0.0001), dead cells in the tubular epithelium (p < 0.0001) and iron deposition (p < 0.01) in mice with cisplatin induced AKI. And SSF downregulated macrophage infiltration (p < 0.01), the expressions of high mobility group box 1 (HMGB1, p < 0.05) and interleukin (IL)-17 (p < 0.05), upregulated superoxide dismutase (SOD) 1 and 2 (p < 0.01), and catalase (CAT, p < 0.05), and alleviated mitochondrial dysfunction (p < 0.05). More importantly, SSF regulated iron transport and intracellular iron overload and reduced the expression of ferritin (p < 0.05). Moreover, it downregulated the expressions of cyclo-oxygenase-2 (Cox-2, p < 0.001), acid CoA ligase 4 (ACSL4, p < 0.05), and solute carrier family 7, member 11 (SLC7A11, p < 001), upregulated glutathione peroxidase 4 (GPX4, p < 0.01) and p53 (p < 0.01), and decreased 4-hydroxynonenal (4-HNE) level (p < 0.001).
Conclusion: SSF attenuates AKI by inhibiting ferroptosis mediated by p53/SLC7A11/GPX4 pathway.
Keywords: acute kidney injury, cisplatin, ferroptosis, shenshuaifu granule, p53/SLC7A11/GPX4 pathway