The Effect And Mechanism Of Oil Extract From Alpinia Oxyphylla Miq.fruit On Learning And Memory Impairment In Mice

Objective : To study the effect of oil extract from Alpinia Oxyphylla Miq.fruit(AOFOE)on learning and memory impairment mice,and to preliminarily explore the mechanism.Methods:1.The activity of anti-acetylcholinesterase and anti-oxidative of AOFOE Ellman method was used to determine the antiacetylcholinesterase activity of AOFOE,and DPPH method was used to determine the antioxidant activity of AOFOE.2.The improving effect of AOFOE on learning and memory of memory impairment mice model KM mice were randomly divided into 5 groups,namely the normal group,the model group,the low-dose group of AOFOE(AOFOEL group,0.5 m L/kg),the high-dose group of AOFOE(AOFOE_H group,1 m L/kg),and the donepezil hydrochloride group(3 mg/kg).Mice in the normal group and model group were given normal saline,and the other mice were given corresponding drugs for 27 d,once a day.From the 22 nd day,the mice in the normal group were intraperitoneal injection(ip)normal saline(0.9% Nacl),while the other mice were ip 3 mg/kg of scopolamine hydrobromide solution for consecutive 6 days,once a day.Thus learning and memory impairment model was established.30 minutes later after the last time of ip scopolamine hydrobromide solution,the Morris water maze experiment was used to investigate the behavior of mice.The water maze experiment was over,4 mice in each group were randomly selected and killed,thus the brain were usually stained by HE.Then the morphology and structure of neurons in the CA1 area of the hippocampus were observed under an optical microscope.3.Mechanism of improving learning and memory in memory impairment mice model of AOFOE After the Morris water maze experiment,the remaining mice in each group were anesthetized and their venous blood was taken from the eyes veins,kept the serum for tested;and the hippocampus were quickly stripped on ice and homogenized.It were detected which the activity of ACh E and Ch AT in hippocampus and the activity of SOD?GSH-Px and the content of MDA in serum and hippocampus.The relative expressions of the m RNA of BDNF?ERK?CREB?BCL-2and BAX in hippocampus were detected by real-time polymerase chain reaction.Meanwhile,the relative expression levels of protein of p-ERK1/2?p-AKT473 ? cleaved caspase-3 in hippocampus were detected by western blotting.Results:1.With the increase of concentration of AOFOE,the inhibitory activity of acetylcholinesterase was enhanced,the IC50 was 25.63 ?g/ml.With the increase of AOFOE concentration,DPPH radical scavenging rate increased gradually,and the AOFOE concentration was 8.523 mg/m L when the scavenging rate was 50 %.2.The learning and memory impairment in mice was successfully induced by Scopolamine.Experiment of Morris water maze test showed that:compared with model group,the escape latency shorten?the residence time in the first quadrant ? increased ? the distance percentage of first crossing quadrant ? increased?the crossing platform times increased,the first time across platform time shorten,and swimming path significantly shorten in the mice of AOFOE_H group and donepezil hydrochloride group(P < 0.05 or P <0.01).The morphology of neurons in the hippocampal CA1 region stained by HE of the model group was irregular with no obvious nucleoli.After the drug intervention,the neurons in the hippocampal CA1 region of the AOFOE_H group and donepezil hydrochloride group were orderly arranged and the cell structure was relatively normal.3.Compared with the model group,the activity of ACh E decreased and Ch AT increased in the hippocampus of the mice of the AOFOE_H group and donepezil hydrochloride group(P < 0.05 or P < 0.01);The activity of SOD,GSH-Px were increased and the content of MDA was decreased in serum and hippocampus of the mice of AOFOE_H group and donepezil hydrochloride group(P < 0.05 or P < 0.01);m RNA levels of BDNF?ERK?CREB and BCL-2in the hippocampus were significantly increased by PCR analysis of the AOFOE_H group and donepezil hydrochloride group,while the m RNA levels of BAX were decreased.The expression of p-AKT473 ? p-ERK1/2 were up-regulated,and the cleaved caspase-3 were down-regulated by Western blotting analysis.Conclusion:The AOFOE has latently improving effect on learning and memory in memory impairment mice model.The mechanism maybe includes:regulating the activity of ACh synthase and catabolase in the central nervous system;improving the body's antioxidant capacity;Up-regulating the expression of the gene of BDNF ? ERK ? CREB ? BCL-2 and the protein of p-ERK1/2 ?p-AKT473,and down-regulating the expression of the gene BAX and the protein of cleaved caspase-3.