Abstract: Abstract:Objective
To investigate the influence of garlic polysaccharide(GPL) in the  learning and memory abilities  of mice with chronic alcoholism, and to explain the protective effect and its mechanism,and to provide experimental basis for developing natural medicine for prevention and treatment for  alcohol-related brain damage.Methods 94 Kunming mice were randomly divided into normal group,model group,GPL low　dose,GPL medium dose and GPL  high dose(150,200,and 250 mg•kg^-1•d^-1)  groups;there were 14 mice in normal group and 20 mice in the other each group. The mouse model of brain damage induced by  chronic alcoholism was  constructed  by gastric perfusion of  56°spirit and then the mice were treated with different doses of GPL.Place navigation and spatial probe tests in Morris water maze(MWM) were conducted to detect the learning and memory abilities of mice according to their escape latencies,staying  time in target quadrant,and times of crossing platform in the 6th and  9 th weeks. After ten weeks,the activities of acetylcholinesterase (TChE) and monoamine oxidase(MAO) in the   brain tissue of mice were detected  and  the morphological changes of mouse  brain tissue were observed by  light microscope.  Results Compared  with normal group,the mice in model group had longer escape latency in the  6th and 9th weeks (P<0.05),less time in target quadrant and fewer times of crossing the platform in the 9th week (P<0.05). Compared with normal group,the activities of TChE and MAO in the  brain tissue of the mice in  model group were increased statistically (P<0.05) and the cerebral hippocampal C1 area in model group showed more cell necrosis and edema after 10 weeks.Compared  with  normal group,the mice in  GPL high dose group had longer escape latency,less time in target quadrant,fewer times of crossing the platform (P<0.05) on the 2nd day in the 9th week  while the mice in the other two GPL groups had no statistical differences (P>0.05). Compared with  model group,the mice in three GPL groups had shorter escape latencies in the  6th and 9th weeks(P<0.05) and the mice in GPL  low and medium doses  groups had longer time in target quadrant and more times of crossing the platform in the  9th week (P<0.05). Compared with model group,the activities of TChE and MAO in the brain tissue of the mice in  three GPL groups were decreased statistically (P<0.05) and  after 10 weeks the cerebral hippocampal C1 area of the mice in these groups showed fewer necrotic cells,especially in GPL  medium dose group.  Conclusion GPL has anti-agonistic effect on the   injury of brain cells and the decresing of learning and  memory abilities induced by chronic alcoholism and its mechanism may be related with regulating and improving the function of cholinergic and nervous system.

Key words: garlic polysaccharide, chronic alcoholism, abilities of learning and memory