Objective: To investigate the effect of Panax Notoginseng Saponins(PNS)on neuronal apoptosis and mitochondrial apoptosis pathway and c-Jun N-terminal kinase (JNK) activation after cerebral ischemia-reperfusion injury in mice. Method: C57BL／6 mice were randomly divided into sham-operation group

model group

PNS group and edaravone group.Cerebral ischemia-reperfusion injury was prepared by bilateral common carotid artery ligation for 20 min followed by reperfusion for 24 h and 48 h after drug administration for 4 days.Neuronal apoptosis was determined with Tunel and the expression of p-JNK1/2

cysteine-asparate protease -9(caspase-9)

caspase-3 and cytochrome C (CytC) protein in brain tissue was detected with Western-blot. Result: After cerebral ischemia for 20 min followed reperfusion for 24 and 48 h

the neuronal apoptosis rate was enhanced significantly(P<0.01)

the expression of p-JNK1/2

CytC

caspase-9 and caspase-3 protein in brain tissue was increased (P<0.01).The neuronal apoptosis rate in the PNS group was significantly lower than that of the model group(P<0.01)

the expression of p-JNK1/2

CytC

caspase-9 and caspase-3 protein in PNS group was lower than that of the model group significantly(P<0.01 or P<0.05). Conclusion :PNS could attenuate neuronal apoptosis rate by inhibiting activation of signal transduction of JNK and mitochondrial apoptosis pathway after cerebral ischemia/reperfusion injury in mice.