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 3h after renal ischemia. At the same time, ginaton attenuated the increased expression of FasL at 3h and caspase3 immunoreactivity at 6h 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.