BACKGROUND:Ginsenoside extracted from the stem and leaf of ginseng(GSL)and choline have both been shown to improve leing and memory functions; however,further studies are needed to understand the synergistic effects of a combination of both.OBJECTIVE:To verify the combined improved synergistic effects of GSL and choline on leing and memory disorders in rats.DESIGN:Control observation.SETTING:Taishan Medical College.MATERIALS:A total of 150 male Kunming mice weighing(20±2)g and 40 healthy male Wistar rats weighing(220±20)g were provided by the Experimental Animal Department of Jilin University.Animal experimentation received confirmed consent from the local ethic committee.GSL was provided by the Department of Chemistry,Norman Bethune Medical University,and choline was provided by the Third Experiment Factory,Shanghai.METHODS:This study was performed at the Life Science Institute,Taishan Medical College from October 2006 to February 2007.①Scopolamine-induced leing and memory disorders in rats:Forty rats were randomly divided into control group,model group,combination group(400 mg/kg GSL + 200 mg/kg choline),GSL(400 mg/kg)group,and choline(200 mg/kg)group,8 rats/group.Rats were perfused and administrated in the ming,once a day for 14 successive days.Rats in the control group and model group were perfused with 20 mL/kg distilled water and underwent Morris water maze spatial resolution test 1 hour after perfusion on the 10th,11th,and 12th days after administration.Rats also underwent passive step-down avoidance test 1 hour after reperfusion on the 13th and 14th days after administration.Thirty minutes prior to experimentation,rats in the remaining three groups were intraperitoneally(I.p)injected with 2 mg/kg scopolamine,and rats in the control group were I.p.injected with 2 mL/kg saline.②Scopolamine-induced leing disorder and memory acquired disorder in mice:Fifty mice were randomly divided into control group,model group,combination group(400 mg/kg GSL +200 mg/kg choline),GSL(400 mg/kg)group,and choline(200 mg/kg)group,with 10 mice/group.Mice were perfused and administrated in the ming,once a day for 9 successive days.Mice in the control group and model group were perfused with 20 mL/kg distilled water and underwent passive step down avoidance test 1 hour after reperfusion on the 8th and 9th day after administration.Twenty minutes prior to training,mice in the remaining three groups were I.p.injected with 2 mg/kg scopolamine,and mice in the control group were I.p.injected with 10 mL/kg saline.③ Sodium nitrite-induced memory consolidation disorder in mice:Grouping,administration,and testing were the same as mentioned above.After training,mice in the remaining three groups were immediately subcutaneously injected with 120 mg/kg sodium nitrite,and mice in the control group were subcutaneously injected with 20 mL/g saline.④Ethanol-induced memory reconsotidation disorder in ice:Grouping,administration,and testing were the same as mentioned above.At 24 hours after training and 20 minutes before retraining,mice in the remaining four groups were perfused with 10 mL/kg ethanol(0.3 volume fraction),and mice in the control group were perfused with 10 mL/kg saline.MAIN OUTCOME MEASURES:Synergistic effects of GSL and choline on leing and memory deficits induced by scopolamine,sodium nitrite,and ethanol in experimental animals.RESULTS:All 40 rats and 150 mice were included in the final analysis.①Synergistic effects of GSL and choline on leing and memory disorders induced by scopolamine in rats:During passive step-down avoidance and Morris water maze spatial resolution tests,the number of error responses and length of maze training in the model group were significantly greater than in the control group(P＜0.01); while the number of error responses and length of maze training in the combination group were significantly less than in the model group,GSL group,and choline group(P＜0.05-0.01 ).The Q value was＞1 after combining administration,which suggests that the combination of GSL and choline had synergistic effects.② Synergistic effects of GSL and choline on leing disorder and memory-acquired disorder induced by scopolamine in mice:During passive step-down avoidance test,the number of error responses in the model group were significantly greater than in the control group(P＜0.01); while the number of error responses in the combination group were significantly less than in the model group,GSL group,and choline group(P＜0.05-0.01).The Q value was＞1 after combining administration,which suggests GSL and choline had synergistic effects.③Synergistic effects of GSL and choline on memory sodium nitrate-induced consolidation disorder in mice:During passive step down avoidance test,the number of error responses in the model group were significantly less than in the control group(P＜0.01 ); while the number of error responses in the combination group were significantly less than in the model group,GSL group,and choline group(P＜0.05-0.01).The Q value was＞1 after combined administration,which suggests GSL and choline had synergistic effects.④Synergistic effects of GSL and choline on ethanol-induced memory reconsolidation disorder in mice:During passive step down avoidance test,the number of error responses in the model group were significantly greater than in the control group(P＜0.01); while the number of error responses in the combination group were significantly less than in the model group,GSL group,and choline group(P＜0.05-0.01).The Q value was＞1 after combined dministration,which suggests GSL and choline had synergistic effects.CONCLUSION:GSL and choline have synergistic effects on leing and memory functions.