Protective effect of a standardized Ginkgo extract (ginaton) on renal ischemia/reperfusion injury via suppressing the activation of JNK signal pathway

A new standardized Ginkgo extract (ginaton) destined for i.v. injection was investigated in rats for its protective effect on renal ischemia/reperfusion injury. We report on the elucidation of the downstream mechanism of action of JNK on the renal ischemia/reperfusion injury, which can be explained as the decrease in JNK phosphorylation at 20 min and c-Jun phosphorylation (Ser63/73) at 3 h after renal ischemia. At the same time, ginaton attenuated the increased expression of FasL at 3 h and caspase3 immunoreactivity at 6 h after renal ischemia. Furthermore, ginaton significantly decreased renal epithelial tubular cell apoptosis induced by renal ischemia/reperfusion, alleviating renal ischemia/reperfusion injury. These results cumulatively indicate that ginaton could suppress the JNK-c-Jun-FasL-caspase3 signaling cascade, protecting renal tubular epithelial cells against ischemia/reperfusion-induced apoptosis, which implies that antioxidants may be a potential and effective agent for prevention of the ischemic/reperfusion injury through the suppression extrinsic apoptotic signal pathway induced by JNK signal pathway.