Protective effects of polydatin on focal cerebral ischemia in rats / 中国组织工程研究

ABSTRACT

BACKGROUND: Free radicals are produced during ischemia, which can strengthen activity of lipid peroxidation; induce lesion of cell and cellular barrier, result in necrosis or apoptosis of neurons; and aggravate edema of ischemic cerebral tissue.OBJECTIVE: To observe the effects of polydatin (PD) on free radicals, lipid peroxidation, water contents and pathological morphology of brain tissue in rats with focal cerebral ischemia so as to explore its protective mechanisms.DESIGN: A randomized controlled trial.SETTING: Intensive Care Unit, Second Affiliated Hospital, Chongqing University of Medical Sciences; Pediatric Research Institute, Children's Hospital Chongqing University of Medical Sciences.MATERIALS The experiment was carried out at the Pediatrics Medicine Institute of Chongqing Medical University from October 2001 to July 2002.Totally 48 healthy adult male Wistar rats were divided into 3 groups randomly,with 16 in each group. Group Ⅰ was sham-operated group rats were anaesthetized, the right common carotid arteries were separated instead of being occluded. Group Ⅱ was ischemia group to establish the right middle cerebral artery occlusion model of rats. Group Ⅲ was PD pretreatment group polydatin (6 g/L, 12 mg/kg) were intravenously administrated 30 minutes before the onset of ischemia. Saline substituted for PD, besides, were intravenously administrated with the same way and dosage on Group Ⅰ, Group Ⅱ and Group Ⅲ.The rats were decapitated and the brains were immediately removed after cerebral ischemia 2 hours. In each group, 8 rats were chosen to be determined water contents of brain tissue, the other 8 rats were chosen to be determined levels of lipid peroxidation and free radicals in brain tissue.METHODS: According to the formula which was wet weight-dry weight/wet weight×100%, water content of cerebral tissue was assayed. Superior liquid was taken to assay MDA with spectrophotometer thiobarbituric acid method (TBA) method, SOD activity assayed by xanthiue oxidase enzyme method, the activities of GSH-Px, CAT and NOS determined by colorimetry,the amount of protein determined by the method of Lowry. All the procedures were carried out strictly according to the instruction.malonaldehyde (MDA) and activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) and nitric oxide synthase chemia, contents of SOD, GSH-Px and CAT in cerebral tissue of PD group were obviously higher than those of ichemia model group [(226.43±8.69),(193.37±11.14) NU/mg; (244.38±12.34), (211.71±16.50) μkat/g; (59.85±9.67),water in cerebral tissue of PD group were obviously lower than those of ichemia model group [(6.38±0.54), (8.63±0.78) μmol/g; (78.72±0.43)%,tivity in ischemic tissue but the results were similar to that in ischemia model group [(12.00±1.00), (12.84±1.17) μkat/g, P ＞ 0.05] in brain tissue.ed that PD alleviated the ischemia edema of cerebral ischemia.CONCLUSION: PD can alleviate the reaction of lipid overoxidation, improve the activities of antioxidant-enxymes, reduce ischemia brain edema,protect the function of cell member, bring down the damage to ischemia neurons. It shows that PD has significant cerebral protective role on focal ischemia brain damage.