Abstract
Renal ischemia-reperfusion (I/R) injury is a major cause of acute kidney injury. The pathogenetic mechanisms underlying renal I/R injury involve inflammation, oxidative stress and apoptosis. Osthole is a coumarin derivative that exhibits potential anti-inflammatory activity. The aim of the present study was to investigate the effect of osthole in renal I/R injury and its underlying mechanism. Renal I/R injury was induced by clamping the left renal artery for 45 min followed by 24 h reperfusion with the contralateral nephrectomy. A total of 70 rats were randomly assigned to seven groups (n=10 per group): Sham; IRI; and osthole (0, 5, 10, 20 and 40 mg/kg) groups. Rats were administered intraperitoneally with osthole 45 min prior to renal ischemia. Serum and renal tissue were harvested 24 h after reperfusion. Renal function and histological changes were assessed. In addition, the mRNA and protein expression of tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8) and interleukin-6 (IL-6) in renal tissue and serum were evaluated using quantitative polymerase chain reaction and ELISA assays, respectively. The protein expression levels of p65, p-p65, janus kinase 2 (JAK2), p-JAK2, signal transducer and activator of transcription 3 (STAT3) and p-STAT3 were measured using western blot analysis. The results indicate that osthole pretreatment was able to significantly attenuate the renal dysfunction in a dose-dependent manner, histological changes and the expression of TNF-α, IL-8, IL-6, p-JAK2, p-STAT3 and p-p65 induced by renal I/R injury. However, neither osthole or I/R injury affected the expression p65, JAK2 and STAT3. Osthole pretreatment is able to reduce renal I/R injury by abrogating inflammation and the mechanism is partially involved in suppressing JAK2/STAT3 activation. Thus, osthole may be a novel practical strategy for the mitigation of renal I/R injury.