[Effect of Chinese medicine Huishen granule on cognitive outcome following diffuse axonal injury: experiment with rats].

OBJECTIVE

To investigate the influence of Chinese medicine Huishen granule (HG) containing ginseng, grassleaved sweet flag rhizome, pilose deer antler, etc, on learning and memory functions in diffuse axonal injury (DAI) and the mechanisms thereof.

METHODS

Impact acceleration method was used to establish DAI Wistar rat models. Twenty model rats were randomly divided into 2 equal groups, the DAI+HG group treated with gastric perfusion of HG 3 times a day since 24 h after the establishment of model for 14 days, and the DAI group without treatment. Ten rats underwent sham operation as controls. Fourteen days after the injury, Morris water maze (MWM) test was used to detect the rat's abilities of learning and memory for continuous 5 days. The changes of escape latency in acquisition of the task, the percentage of time spent in target quadrant, and the number of crossing the point of original platform in probe test were recorded. At day 20 after the-operation, the rats were subjected to long-term potentiation (LTP) recording in hippocampus to measure the percentage of slope and baseline of excitatory post-synaptic potential (EPSP). Two rats from each group were killed 24 h, 14 d, and 20 d after the operation with their brains taken out, HE and immunohistochemical staining were employed to exam the brain lesion at 24 h, day 14 and 20 post-injury.

RESULTS

The escape latency of the DAI group was (32.8+/-4.6) s, significantly longer than those of the DAI+HG and sham operation groups [(20.3+/-0.7) and (16.8+/-0.8) s respectively, both P<0.05]. The target quadrant staying time percentage and number of platform location crossings of the DAI group were (36.4+/-3.2)% and 4.5+/-0.6 respectively, both significantly less than those of the DAI+HG and sham operation groups [(46.0+/-2.4)% and 6.8+/-0.8, and (46.9+/-2.1)% and 8.1+/-0.8 respectively, all P<0.05]. The LTP level of the DAI group was (101.4+/-3.3)%, significantly lower than those of the DAI+HG and sham operation groups [(116.3+/-6.7)% and (117.9+/-2.8)% respectively, both P<0.05]. No significant differences in the parameters were found between the DAI+HG and sham operation groups (all P>0.05). Classical pathological changes of DAI occurred in the brains of the DAI and DAI+HG groups at the time point of 24 h, and mitigated partly at the time points of day 14 and 20.

CONCLUSION

The learning and memory impairment of DAI was ameliorated significantly with the treatment of Chinese medicine HG, owing to the recuperation of synaptic plasticity in hippocampal area.