Carnosol protects against renal ischemia-reperfusion injury in rats

Acute kidney injury, which is caused by renal ischemia-reperfusion injury (IRI), occurs in several clinical situations and causes severe renal damage. There is no effective therapeutic agent available for renal IRI at present. In this study, we performed an experiment based on an in vivo murine model of renal IRI to examine the effect of carnosol. Thirty Sprague-Dawley rats were randomized into three groups (10 rats in each group): the sham, IRI, and carnosol groups. Rats in the carnosol group were injected intravenously with 3 mg/kg of carnosol, and those in the sham and IRI groups were injected intravenously with 10% dimethyl sulfoxide 1 h before ischemia. Rats were sacrificed after 24 h of reperfusion. The blood and kidneys were harvested, renal function was assessed, and histologic evaluation was performed to analyze renal injury. A renal myeloperoxidase activity assay, in-situ apoptosis examination, enzyme-linked immunosorbent assay, immunohistochemical assay, and western blot were also performed. Carnosol pretreatment significantly reduced renal dysfunction and histologic damage induced by renal IRI. Carnosol pretreatment suppressed renal inflammatory cell infiltration and pro-inflammatory cytokine expression. In addition, carnosol markedly inhibited apoptotic tubular cell death, caspase-3 activation, and activation of the p38 pathway. Carnosol pretreatment protects rats against renal IRI by inhibiting inflammation and apoptosis. Although future investigation is needed, carnosol may be a potential therapeutic agent for preventing renal IRI.