DIOSMIN PROTECTS AGAINST CEREBRAL ISCHEMIA/REPERFUSION INJURY THROUGH ACTIVATING JAK2/STAT3 SIGNAL PATHWAY IN MICE

Background and object: Apoptosis is a major form of cell death in cerebral ischemia/reperfusion (I/R) pathogenesis and may represent a target for treatment. Diosmin (DM), a micronized purified flavonoid drug, possesses an anti-apoptotic effect in the treatment of varicose veins and renal injury. However, the effect of DM in the acute phase of cerebral I/R is not clear. This study investigated DM's role in cerebral I/R and its potential mechanism. Methods: Male CD-1 mice were subjected to transient middle cerebral artery occlusion (tMCAO). Experiment 1 was used to evaluate the time course expression of Janus tyrosine kinase-2 (JAK2), signal transducer and activator of transcription-3 (STAT3), phosphorylated JAK2 (pJAK2) and phosphorylated STAT3 (pSTAT3) after cerebral I/R, and six time points were included. In experiment 2, DM was given orally at doses of 50 mg/kg or 100 mg/kg for 6 consecutive days before receiving tMCAO. At 24 h after reperfusion, neurological deficit, Nissl staining, brain water content and infarct volume were examined. Bcl-2, Bax, pJAK2, and pSTAT3 were detected by immunohistochemistry, qRT-PCR and Western blot. Confocal microscope was used to observe the location of pSTAT3 in the cerebral cortex. Results: Compared with Vehicle group, the high dose of DM significantly alleviated neurological deficit, brain water content, infarct volume, increased the Nissl-positive cells, upregulated the expression of pJAK2, pSTAT3 and Bcl-2 and downregulated Bax (P < 0.05). Conclusion: These results showed that DM protected against cerebral I/R injury through activating JAK2/STAT3 signal pathway. (C) 2014 IBRO. Published by Elsevier Ltd. All rights reserved.