The Ameliorative Effect And Mechanism Of Procyanidins Extracted From The Lotus Seedpod On Age-associated Memory Impairment In Rats

PART 1:Procyanidins extracted from the lotus seedpod ameliorates scopolamine-induced memory impairment in miceObjective:To determine the effect of procyanidins extracted from the lotus seedpod (LSPC) on the learning and memory impairments induced by scopolamine (1 mg/kg, i.p.) in mice.Methods: Fifty male Kun-Ming rice were randomly divided into five groups, ten in each: control, model, L-LSPC (50 mg/kg), M-LSPC (100 mg/kg) and H-LSPC (150 mg/kg); the last three groups were were given 50, 100, 150 mg/kg BW LSPC by orally by a gavage daily for 30 days respectively, while the other two groups were given orally an equivalent volume of distilled water daily. The model of learning and memory impairment was established by scopolamine (1 mg/kg, ip.) ten minutes before the beginning of the test. 30 days later the effect of LSPC on learning and memory of the mice were tested by Morris water maze and 7 days after that step-down avoidance tests can be carried out. The cholinergic system was also studied by the assessment of the activity of AChE in brain.Results: All three doses of LSPC (50, 100, 150 mg/kg BW, p.o.) reversed scopolamine-induced learning and memory impairments in both the Morris water maze and the step-down avoidance tests. In the Morris water maze test, the groups treated with LSPC have significantly shorter escape latencies and swimming distances than scopolamine group; while in the step-down avoidance test, all three dose groups had significantly less number of errors and longer latency than scopolamine group. In addition, LSPC was also found to inhibit acetyl cholinesterase (AChE) activity. Conclusion: LSPC can improve the learning and memory capacities of young rats impaired by scopolamine, and the mechanism probably lay on its effect on cholinergic system.PART 2:Procyanidins extracted from the lotus seedpod ameliorates age-associated memory impairment in rats and its possible mechanism.First:Procyanidins extracted from the lotus seedpod ameliorates age-associated memory impairment in ratsObjective:To study the effects of LSPC on age-associated memory impairment in rats.Methods: According to the results of Morris water maze screening test, 200 old female SD (Sprague–Dawley) rats (older than 18 months) were divided into four groups: AU(aged unimpaired), AI(aged impaired), L-LSPC(50 mg/kg) and H-LSPC(100 mg/kg); another 20 young SD rats (4-month-old) was choosed as Young group. L-LSPC and H-LSPC were were given 50, 100 mg/kg BW LSPC orally by a gavage daily for 7 weeks respectively, while the other three groups were given orally an equivalent volume of distilled water daily. 7 weeks later the effect of LSPC on the learning and memory of age-associated memory impairment rats were tested by Morris water maze.Results: In the Morris water maze test, the two LSPC (50, 100 mg/kg BW, p.o.) groups show significantly shorter escape latencies and swimming distances than AI group with a dose-dependent tendency. Conclusion: LSPC can improve the learning and memory capacities of the age-associated memory impairment rats in Morris water maze.Second:Procyanidins extracted from the lotus seedpod ameliorates the oxidative stress damage of age-associated impairment rats.Objective:To study the effects of LSPC on the oxidative stress damage and antioxidation system of age-associated impairment rats.Methods: The parameters of total antioxidant capacity (TAO-C), malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and Carbonyl content in hippocampus and cerebral cortex were determined by spectrophotometer to observe the alterations of oxidative damage and antioxidant state after LSPC intervention compared with age-associated memory impairment rats.Results: The oxidative damage level of the AU and AI groups are higher than the young group, there is no statistically significant difference between AU and AI. The groups treated with LSPC significantly ameliorated the oxidative stress damage and increased antioxidants and antioxidant enzyme levels with a dose-dependent tendency. Conclusion: LSPC can play some protective roles on the brain tissues of age-associated memory impairment rats by reducing brain oxidative stress damage and improving the antioxidant level and antioxidant enzyme activity.Third:Procyanidins extracted from the lotus seedpod ameliorates the cholinergic system of age-associated impairment in rats.Objective: To study the effects of LSPC on the cholinergic system of age-associated memory impairment in rats.Methods: The parameters of acetylcholine ACh, acetylcholine transferase ChAT, acetylcholinesterase activity of AChE were determined to observe the alterations of cholinergic system after LSPC intervention compared with age-associated memory impairment rats. Results: The acetylcholine level of the AI group was significantly lower than the AU group and the young group. The groups treated with LSPC can significantly increased the acetylcholine level, and with no statistically significant difference to the AU and young group. The acetyl cholinesterase activity in AI group significantly reduced compared to the young group, the LSPC groups'acetylcholinesterase activity was significantly increased, and showed a dose-response tendency. The activity of acetylcholine transferase between each group was no significant difference.Conclusion: LSPC can reverse the reduction of acetylcholinesterase activity, as well as to improve the level of acetylcholine to ameliorate the cholinergic system of brain tissue in rats, and then improve their learning, memory and cognitive capabilities.