Dendrobium nobile polysaccharides reduce cerebral ischemia reperfusion injury in rats / 中成药

ABSTRACT

AIM To investigate the protective effects of polysaccharides from Dendrobium nobile Lindl.on cerebra ischemia/reperfusion injury in rats and its possible mechanism of action.METHODS One hundred and five SD rats were divided into sham group,model group,Nimodipine group (10 mg/kg) and treatment groups with low-,medium-,and high dose (50,100,and 200 mg/kg) of polysaccharides from D.nobile.The right middle cerebral artery of rats was occluded by inserting a.thread through internal carotid artery for 2 h,and was sampled after reperfusion for 24 h.The rats received gavage once a day for 7 d before operation.Neurological deficits score,brain index,brain water content and infarct size in rats were conducted at the end of reperfusion;the activity of superoxide dismutase (SOD),glutathione peroxidase (GSH-Px),myeloperoxidase (MPO) and the content of malondialdehyde (MDA) of brain tissue and blood serum were measured by chemical colorimetry;the infiltration of neutrophile granulocyte in rat ischemic cortex were detected with immune-fluorescence staining.RESULTS Sham group had no neurological deficit,but the model group showed severe neurological deficits,meanwhile,the infarct size,brain index and brain water content rose markedly,the content of MDA and the activity of MPO of the brain tissue and the blood serum increased remarkably,while the activity of SOD and GSH-Px apparently decreased;compared with the model group,neurological deficits of rats were improved significantly in polysaccharides from D.nobile dose groups,moreover,the infarct size,brain index and brain water content markedly declined,the MDA level and the activity of MPO significantly decreased,but the activity of SOD,GSH-Px increased remarkably;the infiltration of neutrophile granulocyte in the high dose group significantly decreased compared with the model group.CONCLUSION Polysaccharides from D.nobile has some neuroprotective effects on local cerebral ischemia/reperfusion injury,and that may be related to the remove of oxygen free radicals and the decrease in inflammation reaction.