ABSTRACT
Objective To evaluate the effect of alginate polysaccharide JM on rats impaired by brain ischemia,and to elucidate its mechanisms.Methods By using the middle cerebral artery occlusion(MCAO) induced by nylon surgical thread inserted through the internal carotid artery into the anterior cerebral artery in rats,the effects of JM on neurological dysfunction and infarct volumn in rats brain were investigated.Neuroblastoma SH-SY5Y cells were employed to study the inhibitory effects of JM on cytotoxicity induced by hypoxia-hypoglycemia.Results JM at the doses of 12.5 and 25 mg?kg-1,iv,30 min before ischemia impressed neurological dysfunction,characterized by the decreased behavioral obstacle scores of MCAO rats.The infarct volumn declined 24h after ischemia as well.Further investigation by flow cytometry revealed that JM significantly reduces the overloading of intracellular free calcium on and suppresses apoptosis induced by hypoxia-hypoglycemia in human neuroblastoma SH-SY5Y cells.Conclusion JM showed protective effects on brain ischemia,probably related to its inhibitory effect on the overloading of intracellular free calcium ion(\i) and cell apoptosis.