Neuroprotective effect of antisense oligodeoxynucleotides in experimental intracerebral hemorrhage in rats

Using a collagenase-induced rat model of intracerebral hemorrhage (ICH), we showed that ICH is characterized by parenchymal hematoma formation with surrounding inflammation and tissue destruction. Our continuous works on the role of inflammation and free radicals in the pathogenesis of neurological deficit and tissue damaging in ICH showed that treatment with fucoidan (anti-inflammatory), or immunosuppresant FK-506, or free radical trap NXY-059, or Minocycline (matrix metalloproteinase down-regulating) could reduce brain damage and improve behavioral outcome in rats following ICH. We further demonstrated that intracerebral injection of antisense oligodeoxynucleotides (ORF4-PE) to target pro-inflammatory cytokine significantly reduced tumor necrosis factor (TNF-α) mRNA and protein expression in striatum and cortex in rats after ICH, and that this was also accompanied by reduced neuronal loss and decreased neurological deficits (STROKE 2001:32:240-248). The present study tested whether administration of ORF4-PE via the ipsilateral internal carotid artery (ICA) is also effective in the same animal model. Briefly, 26 SD rats were pentobarbital anesthetized and ICH was induced by intrastriatum collagenase injection. The ipsilateral external carotid artery was cannulated near the carotid bifurcation for injection of ORF4-PE into the ICA one hour after ICH procedure. Rats received ORF4-PE 20, 200, 2000 μg in 200 ml saline given over 30 minutes, or only 200 ml saline as control. Neurological deficits (postural reflex, circling, beam walking) were assessed at 24 and 48 hours after ICH. Neutrophil level around the hematoma was determined by histo-pathological examination at 24 and 48 hours. There was a dose-dependant improvement in both neurological deficit score and neutrophil infiltration in ORF4-PE treated group vs control group. In particular, the differences were highly significant (p<0.001) in the group treated with 2000 μg ORF4-PE. ICA administration might be an effective and practical means of delivery of ORF4-PE to the brain following ICH in rats.