Protective effect of Salvia Miltiorrhizae injection on N(G)-nitro-d-arginine induced nitric oxide deficient and oxidative damage in rat kidney

N(G)-nitro-d-arginine (d-NNA) could convert into N(G)-nitro-l-arginine (l-NNA) in vivo, and kidney is the major target organ. In the chiral inversion process, a number of reactive oxygen species (ROS) were generated and NOS activity was inhibited, which may cause renal damage. Salvia miltiorrhiza (SM), a traditional Chinese drug, was used in the treatment of cardiovascular diseases and chronic renal failure. The aim of the present study was to investigate the kidney damage caused by d-NNA administration for 12 weeks and to evaluate the effects of treatment with SM on d-NNA-induced kidney damage. The rats, induced with d-NNA for period of 12 weeks, showed significant elevation of Blood Urea Nitrogen (BUN), Creatinine (Crea) and MDA levels, and significant decrease of SOD and GSH-Px activities, as compared with control group. In addition, the kidney of rats induced with d-NNA only showed remarkable histopathology, including severe mononuclear cell infiltration, mild tubular dilatation and congestion, and moderate interstitial desmoplasia. After 4 weeks SM treatment, the activity of SOD, GSH-Px and iNOS and the production of NO were significantly higher (P < 0.05), and the levels of BUN, Crea and MDA were significantly lower than that of d-NNA only group (P < 0.05). In addition, treatment with SM showed histopathological protection in tubular dilatation, congestion, mononuclear cell infiltration and interstitial desmoplasia. The present results indicate that the toxicity of d-NNA relates to its ability to generate oxidative stress and upregulate NOS activity in rat kidney. SM probably ameliorates d-NNA-induced nephrotoxicity in rats according to scavenging free radical and upregulating NOS activity.