BACKGROUND AND OBJECTIVE: Stroke is the second leading cause of mortality in the worldwide. After a stroke, many neurons in the ischemic penumbra will undergo apoptosis. The aim of this study was investigation of effects of iron oxide nanoparticles and magnetic field on apoptosis reduction after ischemic reperfusion in rat model.
METHODS: In this experimental study, 50 male Wistar rats weighing 220-250g were randomly divided into five groups of 10 rats each: including control, sham (ischemic reperfusion model), ischemic reperfusion + iron oxide nanoparticles (10mg/kg), ischemic reperfusion +magnetic field (1 Tesla, 20 min in 4 days), and ischemic reperfusion + iron oxide nanoparticles and magnetic field groups. Injections were performed intraperitoneally.  After Four days, the hippocampi were removed for studying of Apoptosis Induction (by TUNEL technique) and changes in Bax gene expression (by Q-PCR method).
FINDINGS: After induction of ischemic reperfusion, TUNEL⁺ cells number treated with iron oxide nanoparticles (7±2) and or the magnetic field  (12±2) had significant decrease (p<0.01) relative to ischemic reperfusion group (27±5) during 4 days. But simultaneous treatment with nanoparticles and magnetic field (23±2.6) did not show significant difference compared to ischemic reperfusion group (27±5) during 4 days. Furthermore Bax gene expression decreased in iron oxide nanoparticles treated group (2.46±0.22) or the magnetic field exposed group (3.28±0.33) significantly (p<0.01)compared to ischemic reperfusion model (5.21±0.73)..
CONCLUSION: It seems that iron oxide nanoparticles as well as magnetic field to be two effective methods in decrease of apoptosis after ischemic reperfusion.