Neuroprotective effect of fucoidin on lipopolysaccharide accelerated cerebral ischemic injury through inhibition of cytokine expression and neutrophil infiltration.

In our previous study, we reported that lipopolysaccharide (LPS) activated microglia and accelerated cerebral ischemic injury in the rat brain through the overexpression of cytokines in microglia. In the present study, we investigated the effect of the intraperitoneal administration of fucoidin, a potent inhibitor of leukocyte rolling and anti-inflammatory agent, against accelerated cerebral ischemic injury by LPS pretreatment using rats. We found that fucoidin treatment inhibited the expressions of some brain cytokine or chemokine mRNA such as IL-8, TNF-α and iNOS in the brain of the rats treated only with LPS. We also observed that fucoidin treatment dramatically decreased the infarct size in accelerated cerebral ischemic injury induced by LPS treatment at an early time after ischemic injury. In addition, the immunoreactivity of myleoperoxidase (MPO), a marker for quantifying neutrophil accumulation, was distinctively decreased in the ischemic brain of the fucoidin-treated rat. In brief, our results indicate that fucoidin showed a neuroprotective effect on LPS accelerated cerebral ischemic injury through inhibiting the expression of some cytokine/chemokine and neutrophil recruitments.