Attenuation of renal ischemia/reperfusion injury by a polysaccharide from the roots of Dipsacus asperoides.

Renal ischemia-reperfusion (I/R) injury is a leading cause of acute renal failure and one of the major problems after I/R is the production of large amounts of reactive oxygen species (ROS). The present study was performed to evaluate the interference of a polysaccharide (WRDAP-1) from the roots of Dipsacus asperoides in I/R-induced renal injury in rats to determine whether it was mediated by the protective mechanism against oxidative stress to kidney. In vitro experiment, WRDAP-1 exhibited a potent scavenging ability on superoxide radical and hydroxyl radical. Renal protective effect of WRDAP-1 was evaluated in serum levels of blood urea nitrogen (BUN), creatinine, lactate dehydrogenase (LDH), superoxide dismutase (SOD) and serum malonaldehyde (MDA), as well as some renal tissue antioxidant enzymes activities like SOD glutathion peroxidase (GSH-Px) and catalase (CAT). Pretreatment with WRDAP-1 produced reduction in serum levels of BUN, creatinine and LDH caused by I/R injury and significantly improved serum enzymatic activity of SOD and serum MDA level. Additionally, antioxidant enzymes activities of SOD, GSH-Px and CAT in renal tissue were also elevated by WRDAP-1. Collectively, administration with WRDAP-1 significantly improved renal function of I/R rats especially in the rats treated with higher dose of the polysaccharide. Therefore the findings of this study imply that the protective effect of WRDAP-1 against renal I/R injury in rat kidneys could be due to its antioxidant and free radical scavenging activities. WRDAP-1 seems to be a highly promising agent for protecting tissues from oxidative damage and preventing kidney damage due to renal I/R.