The effect of picroside II on the ERK1/2 signal transduction pathway and its neuroprotective effect on the cerebral ischemic injury in rats / 中华行为医学与脑科学杂志

ABSTRACT

Objective To explore the neuroprotective effect and mechanism of picroside II on ERK1/2 signal transduction pathway after cerebral ischemia injury in rats.Methods The focal cerebral is-chemic models were established by inserting a monofilament threads into middle cerebral artery occlusion (MCAO) in 100 Wistar rats and treated by injecting picroside II (20 mg/kg) intraperitoneally.The neu-robehavioral function was evaluated by modified neurological severity score points ( mNSS) test.The cerebral infarct volume was measured by tetrazolium chloride ( TTC) staining.The apoptotic cells were counted by terminal deoxynucleotidyl transferase dUTP nick end labeling ( TUNEL) assay.The expression of pERK1/2 in cortex was determined by the immunohistochemistry ( IHC) and Western Blot ( WB) .Results mNSS test showed that severe neurological dysfunction was found in model and LPS groups,and the scores of mNSS were significantly increased;meanwhile the scores of mNSS in treatment group and U0126 group were signifi-cantly lower than that in model and LPS groups (P<0.05).TUNEL assay showed that the apoptotic cell inde-xes (ACI) in different groups were (0.06±0.02),(0.27±0.03),(0.07±0.02),(0.26±0.03)and(0.09± 0.05) ,and the ACI in treatment and U0126 groups was obviously lower than that in model and LPS groups (P<0.05) .With IHC and WB,pERK1/2 level in model group was the highest,which was slightly higher than that of LPS group,and pERK1/2 expression in treatment and U0126 groups was significantly decreased com-pared with that in model and LPS groups (P<0.05) .Conclusion The activation of ERK1/2 by cerebral is-chemia could induce the cell apoptosis.Picroside II might reduce cell apoptosis by inhibiting the activation of ERK1/2 in ischemic brain injury.