Effects of EGB on hippocampus CA1 region Caspase-9P35 activity in dementia rats induced by Dgal

Objective To investigate the effect and mechanism of extract ginkgo biloba (EGb) on learning memory ability and hippocampus CA1 region Caspase-9P35 activity in dementia rats induced by D-gal.Methods 48 rats were randomly divided into six groups.The dementia model were established by injecting intraperitoneally with the D-gal and each EGb group was injected different doses of EGb simultaneously.TUNEL method was used to detect apoptosis of hippocampal neurons in the CA1 region.Immunohistochemistry and Western Blot were used to determine the expression of Caspase-9P35 in hippocampus CA1 region.Results Compared with the normal group,TUN EL-positive neurons ( (37.8 ± 1.3 ),(0.8 ± 0.2 ) ) and the activity of Caspase-9P35 ( (37.6 ±1.8 ),(6.2 ± 1.3 ) ) had significant increase in hippocampal CA1 subfield of D-gal group (P ＜ 0.01 ).Contrast to D-Gal group,TUNEL-positive neurons ( ( 17.6 ± 0.9),(9.8 ± 0.8 ),( 37.8 ± 1.3 ) ) and the activity of Caspase9P35( (28.6 ± 1.3),(25.0 ± 1.6),(37.6 ± 1.8) ) were significant decreased in EGb-M and EGb-H group (P＜0.01 ).While TUNEL-positive neurons and the activity of Caspase-9P35 had not significant difference in the therapy group than D-Gal group (P ＞ 0.05).Conclusion EGb can improve the cognitive level of the dementia rats.One of the therapeutic mechanisms may be to decrease the hippocampus CA1 region Caspase-9P35 activity.The results of the pretreatment group was more effective than the therapy group. Key words: Dementia; Extract ginkgo biloba; D-Gal; Rat; Caspase