Attenuation of renal ischemic reperfusion injury by salvianolic acid B via suppressing oxidative stress and inflammation through PI3K/Akt signaling pathway

Salvianolic acid B (SAB) is one the major phytocomponents of Radix Salvia miltiorrhiza and exhibit numerous health promoting properties. The objective of the current study was to examine whether SAB exerts a renoprotective effect by attenuating oxidative stress and inflammatory response through activating phosphatidylinositol 3-kinase/serine-threonine kinase B (PI3K/Akt) signaling pathway in a renal ischemic reperfusion rat model. Forty Sprague-Dawley male rats (250-300 g) were obtained and split into four groups with ten rats in each group. The right kidney of all rats was removed (nephrectomy). The rats of the Control group received only saline (occlusion) and served as a sham control group, whereas rats subjected to ischemic reperfusion (IR) insult by clamping the left renal artery served as a postitive control group. The other 2 groups of rats were pretreated with SAB (20 and 40 mg . kg(-1) . day(-1)) for 7 days prior IR induction and served as treatment groups (SAB 20 + IR; SAB 40 + IR). Renal markers creatinine (Cr) and blood urea nitrogen (BUN) were significantly lower in the groups that received SAB. Pretreatment with SAB appears to attenuate oxidative stress by suppressing the production of lipid peroxidation products like malondialdehyde as well as elevating antioxidant activity. The concentration of inflammatory markers and neutrophil infiltration (myeloperoxidase) were significantly decreased. Meanwhile, PI3K protein expression and pAkt/Akt ratio were significantly upregulated upon supplementation with SAB, indicating its renoprotective activity. Taken together, these results indicate that SAB can therapeutically alleviate oxidative stress and inflammatory process via modulating PI3K/Akt signaling pathway and probably ameliorate renal function and thus act as a renoprotective agent.