Protective effect of gypenoside on oxidative damage of the white matter in rats after chronic cerebral hypoperfusion / 中华神经医学杂志

ABSTRACT

Objective To investigate the protective effect of gypenoside (GP) on oxidative damage of the white matter in rats after chronic cerebral hypoperfusion and on its alterations of cognitive function.Methods A total of 57 male SD rats were randomly assigned to 4 groups:sham-operated group (n=12),vehicle group (n=15),200 mg/kg GP treatment group (n=15) and 400 mg/kg GP treatment group (n=15); chronic cerebral hypo-peffused models in the later 3 groups were established by permanent bilateral common carotid artery occlusion (2-VO).The dosage volume of all groups was 10 mL/kg; 3 h after the surgery,all rats orally received the initial administration of 400 mg/kg or 200 mg/kg GP dissolved in saline solution or matched volume of normal saline daily for a consecutive 33 d according to the above-mentioned experimental plan.Spatial learning and memory were assessed using Morris water maze test.Following behavioral tests,the activities of superoxide dismutase (SOD) and changes of malondialdehyde (MDA) level in the corpus callosum and optic tracts were measured by ELISA.The oxidative central nerve cell damages were assessed by immunohistochemical staining for 8-hydroxy-2'-deoxyguanosine (8-OHdG).Results Rats of the 400 mg/kg GP treatment group spent significantly fewer time in finding the platform,but significantly longer time spending in the platform region as compared with those of the vehicle group (P＜0.05).As compared with those in rats of the sham-operated group,the SOD activity was markedly reduced and MDA content was significantly increased in rats of the vehicle group (P＜0.05).Rats of the 400 mg/kg GP treatment group had decreased MDA content,increased SOD activity and decreased 8-OHdG level as compared with rats of the vehicle group (P＜0.05); however,200 mg/kg GP treatment group had no such significant effects as compared with those of the vehicle group (P＞0.05).Conclusion GP can ameliorate the oxidative damage in the corpus callosum and optic tract of rats after chronic cerebral hypoperfusion,indicating that GP may have therapeutic potential for treating dementia induced by chronic cerebral hypoperfusion; however,the related mechanisms for its alteration of cognitive function needs further research.