Effects of ginsenoside of stem and leaf combined with choline on learning and memory ability of rat models with Alzheimer diseases

BACKGROUND： Central adrenergic nerve and 5-serotonergic nerve can influence central cholinergic nerve on learning and memory and make easy for study; however, ginsenoside of stem and leaf （GSL） can improve functions of central adrenergic nerve; moreover, 5-serotonergic nerve and the combination with choline can produce synergistic effect and enhance learning and memory ability so as to improve learning and memory disorder of patients with Alzheimer disease （AD）. OBJECTIVE ： To observe the effects of GSL combining with choline on learning and memory of AD model rats DESIGN ： Randomized grouping design and controlled animal study SETIING ： Department of Pharmacology, Taishan Medical College MATERIALS ： The experiment was carried out in the Pharmacological Department of Medical College of Jilin University from October 1996 to January 1997. Forty healthy male Wistar rats of clean grade were randomly divided into 5 groups, including sham-injury group, model group, GSL group, choline group and combination group, with 8 rats in each group. Main medications： GSL with the volume more than 92.8% was provided by Department of Chemistry, Norman Bethune Medical College of Jilin University. Panaxatriol, the main component, was detected with thin layer scanning technique and regarded as the index of GSL quality [（55±1）%, CV= 2%, n = 5]. Choline was provided by the Third Shanghai Laboratory Factory. METHODS ： 150 nmol quinolinic acid was used to damage bilateral Meynert basal nuclei of adult rats so as to establish AD models. Rats in GSL, choline and combination groups were intragastric administrated with 400 mg/kg GSL, 200 mg/kg choline （20 mL/kg）, and both respectively last for 17 days starting from two days before operation. Rats in sham-injury group and model group were perfused with the same volume of distilled water once in each morning for the same days. （1） Passive avoidance step-down test： Five minutes later, rats jumped up safe platform when they were shocked with 36 V alternating current. If rats jumped down from the platform and the feet touched railings, the response was wrong. Numbers of wrong response were recorded within 3 minutes, and then the test was redone after 24 hours. （2） Morris water-maze spatial localization task： Swimming from jumping-off to platform directly was regarded as right response. Additionally, 4 successively right responses were regarded as the standard. Each rat was trained 10 times a day with 120 s per time for 3 successive days. The interval was 30 s. Three days later, numbers of right response were recorded. The training times were increased to 30 for unlearned rats. （3） Measurement of activity of choline acetylase in cerebral cortex： Rats were sacrificed at 17 days after operation to obtain cerebral cortex to measure activity of choline acetylase with radiochemistry technique. （4） Synergistic effect： It was expressed as Q value： Q value = factual incorporative effect/anticipant incorporative effect; Q ≥ 1 was regarded as synergistic effect. Anticipant incorporative effect = （EA＋EB-EA·EB）, EA and EB were single timing effect, respectively in GSL group and choline group. E（step-down test and Morris water maze test） = （x in model group - factual value in medicine groups）/x in model group; E （activity of choline acetylase） = （factual value in medicine groups -xin model group）/xin model group. MAIN OUTCOME MEASURES ： （1） Passive avoidance step-down test and Morris water-maze spatial localization task in the study of learning and memory; （2） activity of choline acetylase. RESULTS ： All 40 rats were involved in the final analysis. （1） Passive avoidance response： At learning phase on first day and retesting phase on the next day, numbers of wrong responses within 3 minutes were more in model group than sham operation group, and there was significant difference [（5.88±1.46）, （2.25±0.87） times; （2.63±1.06）, （0.50±0.53） times; P 〈 0.01]; numbers of wrong responses within 3 minutes were less in combination group than model group, and there was significant difference [learning phase： （1.12±0.83）, （5.88±1.46） times; retesting phase： （0.38±0.74）, （2.63±1.06）times, P 〈 0.01]; moreover, effect was stronger than that in GSL group and choline group. The Q value was 1.07 and 1.59, respectively and it showed synergistic effect. Spatial localization task： Training times were more in model group than sham operation group, and there was significant difference [（2.9±2.5）, （12.6±3.5） times; P 〈 0.01]. Training times were less in combination group than model group, and there was significant difference [（11.8±2.4）, （27.9±2.5） times, P 〈 0.01]; moreover, effect was stronger than that in GSL group and choline group. The Q value was 1.07 and it showed synergistic effect. （3） Activity of choline acetylase： Activity was lower in model group than sham operation group, and there was significant difference [（30.56±8.33）, （61.11 ±8.33） nkat/g; P 〈 0.01]. Activity was higher in combination group than model group and there was significant difference [（50.00±8.33）, （30.56±8.33） nkat/g, P 〈 0.01];moreover, effect was stronger than that in GSL group and choline group. The Q value was 1.5 and it showed synergistic effect. CONCLUSZON： GSL in combination with choline can synergically improve the disorder of learning and memory of AD model rats. Its mechanism may be involved in enhancing the function of central cholinergic system.

Synergistic effects of ginseng stem and leaf-extracted ginsenoside and choline on improving learning and memory in rats Association verification experiment in animals with multiple learning and memory disorders

BACKGROUND： Ginsenoside extracted from the stem and leaf of ginseng （GSL） and choline have both been shown to improve learning 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 learning and memory disorders in rats. DESIGN： Control observation. SETTING： Taishan Medical College. MATERIALS： A total of 150 male Kunming mice weighing （204-2） g and 40 healthy male Wistar rats weighing （2204-20） 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. ① Scopolamine-induced learning 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 morning, 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 10m, 11m, and 12m days after administration. Rats also underwent passive step-down avoidance test 1 hour after reperfusion on the 13m and 14m 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. ② Scopolamine-induced learning 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 morning, 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/kg saline. ④ Ethanol-induced memory reconsolidation disorder in mice： 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 learning 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. ① Synergistic effects of GSL and choline on learning 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 learning 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. ③ Synergistic 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. ④ Synergistic 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 administration, which suggests GSL and choline had synergistic effects. CONCLUSION： GSL and choline have synergistic effects on learning and memory functions.