Effect of zinc oxide nanoparticles and ferulic acid on renal ischemia/reperfusion injury: possible underlying mechanisms

Abstract

Objectives: The present study examined the effects of ferulic acid (FA) and Zinc oxide nanoparticles (ZnO-NPs) and a combination of both on renal ischemia/reperfusion injury (IRI) in rats and their possible underlying mechanisms. Methods: two-hundreds male Sprague Dawley rats were randomly allocated into the 5 groups; i) sham group, ii) control (IRI) group (occlusion of the left renal pedicle for 45 min), iii) FA group as IRI group with FA (100 mg/Kg oral 24 hrs before ischemia), iv) ZnO-NPs group as IRI group with ZnO-NPs single 5 mg/Kg i.p. 2 hrs before ischemia and v) FA + ZnO-NPs group as IRI group with both FA and ZnO-NPs in the same previous doses. According to the reperfusion times, each group was further subdivided into 4 hr, 24 hr, 48 hr and 7 days reperfusion subgroups. Results: administration of either FA or ZnO-NPs caused significant improvement in the elevated serum creatinine and BUN and malondialdehyde (MDA) concentrations and expression of TNF-α, Bax, caspase-3 in kidney tissues with significant rise in the creatinine clearance, the activities of catalase (CAT) and superoxide dismutase (SOD) and the expression of HO-1, HIF-1α genes and proliferation marker (ki67) in kidney tissues compared to IRI group (p < 0.05). Moreover, a combination of both agents produced more significant improvement in the studied parameters than each agent did alone (p < 0.05). Conclusions: Both FA and ZnO-NPs exerted cytoprotective effects against ischemic kidney injury and a combination of both exhibited more powerful renoprotective effect. This renoprotective effect might be due to suppression of oxidative stress, enhancement of cell proliferation (ki67), upregulation of antioxidant genes (Nrf2, HO-1 and HIF-1α) and downregulation of inflammatory cytokine (TNF-α) and apoptotic genes (caspase-3 and Bax).