Curcumin immune-mediated and anti-apoptotic mechanisms protect against renal ischemia/reperfusion and distant organ induced injuries.

Renal ischemia followed by reperfusion results in kidney injury which in turn produces and releases destructive inflammatory cytokines into the circulation causing subsequent distant organ injury. Little data suggest the immune mechanism of curcumin on protection against ischemia/reperfusion induced injury. We investigated the immunomodulatory and anti-apoptotic effects of curcumin on ischemia/reperfusion (I/R) injury in rats. Thirty-six rats were randomly divided into three experimental groups (sham, I/R and curcumin pretreated I/R, n=12 each). Curcumin was administered orally to curcumin pretreated I/R group. Curcumin can significantly decrease both systemic as well as blood levels of cytokines (p<0.05). Treatment with curcumin also resulted in significant reduction in serum and tissue level of TNF-α, IL-1β, IL-12, IL-18 and INF-γ that were increased by renal I/R injury (p<0.05). Curcumin pretreatment reduce pulmonary apoptotic pathway via significant inhibition of TGF-β and caspase-3 in kidney and lung tissues. Given that pulmonary apoptosis is an important complication of acute renal injury, we identified curcumin protective effect against distant organ I/R induced injury. Based on our results, we concluded that curcumin protects the kidneys and other vital organs against I/R injury via immune-mediated and the new identified anti-apoptotic mechanisms.