The Protective Effect Of Trans-resveratrol On Rats Hippocampus Injury By Aβ_25-35

Objective:To investigate the protective effects of the efficient ingredient of Polygonum cuspidatum trans-resveratrol (TR) on AD rats. Methods After being trained using Morris water maze, rats were randomly divided into 5 groups:(1) sham-operated-group; (2) model-group(3)-(5) were TR high, middle and low dose group, injecting Aβ25-35 to bilateral hippocampus in vivo modeling method. These three groups were treated with TR after the model was established. TR had been intervening in molding rats aim to observe the toxic effect of Aβ25-35.Morris water maze was used to test the ability of spatial learning and memory of rats in 5 groups; TUNEL assay was used to test apoptosis rate of hippocampus and the cortex around cells; Using real-time RT-PCR to detect the mRNA expression of caspase-8,9, inducible nitric oxide synthase (iNOS) in hippocampus and cortex. Results Molding rats by injecting AP25-35 to hippocampus decreased the abilities of spatial memory and increased the mRNA expressions of caspase-8,9 and iNOS mRNA in hippocampus. However, TR intervention group decreased expressions of caspase-8 and iNOS in hippocampus, apoptotic cells decreased also. The mRNA expression of caspase-8 from group (1) to group (5) were 0.27±0.09,1.34±0.87,0.24±0.09,0.29±0.06,0.64±0.15 respectively; The mRNA expression of caspase-9 from group (1) to group (5) were 0.34±0.07,0.98±0.17,0.32±0.13,0.44±0.18,0.91±0.25 respectively; The mRNA expression of iNOS in each group were 0.23±0.90,1.23±0.91,0.34±0.18,0.48±0.12,0.87±0.49 respectively, All intervention group compared with the control group were different (P<0.01). the hippocampus cells apoptotic index(AI) using TUNEL assay in each group were 6±3, 24±3,7±2,11±4,20±3(%) respectively under fluorescence microscope; AI in each group 11day after modeling were 3.23±0.52,21.32±5.02,5.72±1.56,7.21±1.22, 10.93±3.25(%) respectively; intervention group compared with the control group is different (P<0.01). and 17 day after modeling AI were 3.21±0.29,16.31±4.27,5.13±2, 7.12±1.78,9.84±2.66(%) respectively; Same group AI between the 11 day and 17 day is not different (P>0.01). Conclusion Treatment with different dose of TR can reduce Aβ25-35-induced memory impairment in rats. The mechanism may be partly associated with down regulating the mRNA expression of caspase-8 and iNOS in rat hippocampus, and reducing the cell apoptosis in hippocampus.