salvianolic-acid-B and Acute-Kidney-Injury

Contrast-induced acute renal injury (CI-AKI) has become a common cause of hospital-acquired renal failure. However, the development of prophylaxis strategies and approved therapies for CI-AKI is limited. Salvianolic acid B (SB) can treat cardiovascular-related diseases. The aim of the present study was to assess the effect of SB on prevention of CI-AKI and explore its underlying mechanisms. We examined its effectiveness of preventing renal injury in a novel CI-AKI rat model. Compared with saline, intravenous SB pretreatment significantly attenuated elevations in serum creatinine and the histological changes of renal tubular injuries, reduced the number of apoptosis-positive tubular cells, activated Nrf2, and lowered the levels of renal oxidative stress induced by iodinated contrast media. The above renoprotection of SB was abolished by the PI3K inhibitor (wortmannin). In HK-2 cells, SB activated Nrf2 and decreased the levels of oxidative stress induced by hydrogen peroxide and subsequently improved cell viability. The above cytoprotection of SB was blocked by the PI3K inhibitor (wortmannin) or siNrf2. Thus, our results demonstrate that, due to its antioxidant properties, SB has the potential to effectively prevent CI-AKI via the PI3K/Akt/Nrf2 pathway.

Topics: Acute Kidney Injury; Animals; Antioxidants; Apoptosis; Benzofurans; Biomarkers; Cell Line, Tumor; Contrast Media; Creatinine; Cytoprotection; Disease Models, Animal; Iohexol; Kidney Tubules, Proximal; Male; NF-E2-Related Factor 2; Phosphatidylinositol 3-Kinase; Phosphoinositide-3 Kinase Inhibitors; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Rats, Sprague-Dawley; RNA Interference; Signal Transduction; Transfection

The present study was designed to examine whether lithospermic acid B (LSB) isolated from Salvia miltiorrhiza has an ameliorative effect on renal functional parameters in association with the expression of aquaporin 2 (AQP 2) and Na,K-ATPase in the ischemia-reperfusion induced acute renal failure (ARF) rats. LSB showed strong antioxidant activity against production of reactive oxygen species (ROS), ROS-induced hemolysis, and production of lipid peroxide in a dose-dependent manner. Polyuria caused by down-regulation of renal AQP 2 in the ischemia-reperfusion induced ARF rats was partially restored by administration of LSB (40 mg/kg, i.p.), restoring expression of AQP 2, in renal inner and outer medulla. The expression of Na,K-ATPase alpha1 subunit in outer medulla of the ARF rats was also restored in the ARF rats by administration of LSB, while beta1 subunit level was not altered. The renal functional parameters including creatinine clearance, urinary sodium excretion, urinary osmolality, and solute-free reabsorption were also partially restored in ischemia-ARF rats by administration of LSB. Histological study also showed that renal damages in the ARF rats were abrogated by administration of LSB. Taken together, these data indicate that LSB ameliorates renal defects in rats with ischemia-reperfusion induced ARF, most likely via scavenging of ROS.

Topics: Acute Kidney Injury; Animals; Aquaporin 2; Aquaporins; Benzofurans; Blotting, Western; Depsides; Enzyme Inhibitors; Erythrocytes; Free Radical Scavengers; Hemolysis; Hydroxyl Radical; In Vitro Techniques; Kidney; Kidney Function Tests; Lipid Peroxidation; Male; Oxidants; Plant Roots; Proteins; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Salvia miltiorrhiza; Sodium-Potassium-Exchanging ATPase; Superoxides