The Protection Mechanism Of Lycium Barbarum Polysaccharides On Brain Injury In Model Rats With Intracerebral Hemorrhage

ObjectiveResearch the effect of LBP for secondary brain injury in model rats with ICH. Further to explore the neuroprotective effect of LBP and its possible mechanism.Method 180 SD rats were random Ly divided into sham group, model group, LBP low dose group, LBP moderate dose group, LBP high dose group, nimodipine group(n =30). Preoperatively 15 th, LBP low dose group, LBP moderate dose group, LBP high dose group, was given LBP 50, 100, 200 mg?kg-1 gavage, nimodipine group was given nimodipine 40mg·kg-1 gavage, sham group and model group were given the same volume of saline, 1 time / day. After gavage,using autologous blood injection caudate nucleus to build rat ICH model. The Bederson neurological function score of each group of rats were carried out at 4h/8h/12h/24h/48 after ICH. 48 h After ICH, some rats' Brains were removed directly, some rats' Brains were removed after reperfusion with 4% paraformaldehyde. Detect the brain edema volume?brain water content?SOD activity and MDA content in brain tissue of each group of rats. Observe the cell size and morphology after HE staining. The neuronal apoptosis was assessed by TUNEL assay. The impact of LBP on the PAR-1/TNF-?/Bcl-2 expression was detected by Western Blot, immunohistochemistry, and RT-PCR techniques.Result 1.Compared with sham group, the neurological function score of rats was higher in other groups(P<0.05). Compared with the model group at the same time point, the neurological function in LBP moderate/high dose groups at 12 h, 24 h and 48 h was significantly lower(P <0.05), the neurological function in nimodipine group at 24 h and 48 h was significantly lower(P <0.05).2.Compared with sham group, the brain edema volume was larger, brain water content was taller, SOD activity was lower and MDA content was higher in model groups(P<0.05 or P<0.01). Compared with model group, the brain edema volume was alleviated, brain water content was reduced, SOD activity was increased and MDA content was decreased significantly in Each drug treatment group(P<0.05 or P<0.01).3.The HE staining find, After ICH, blood clot can be formed in the ICH region, intermediate mixed with nucleus and cell debris of death cell. And damaged nerve cells and neuroglia cells was disorderly arranged around the ICH region. But it can not find the differences between each treatment group with the model group.4.It was found by TUNEL, both external mechanical stimulation can cause nerve cell apoptosis, morever the ICH caused more significant apoptosis than the simple needle surgery. So, a lot of TUNEL-positive cells distributed in or aroud the ICH region in the model group, but only a small amount of the TUNEL-positive cells can be detected along the needle path in the sham group. Compared with the model group, the TUNEL positive cells' proportion in LBP each dose group and nimodipine group decreased significantly(P <0.01 or P <0.05).5.ICH group of PAR-1 positive cells' proportion,PAR-1 protein expression, PAR-1 m RNA expression was significantly higher than sham-operated group(P <0.05 or P <0.01). Compared with the model group, the PAR-1 protein expression was significantly reduced((P <0.05), the proportion of PAR-1 positive cells was significantly decreased(P <0.01), the PAR-1 m RNA expression was significantly lower(P <0.01) in LBP each dose group and nimodipine group.6.After ICH, the expression of TNF-? was significantly increased and the expression of Bcl-2 was significantly reduced in our present research. Those changes caused after ICH can be intervened by LBP. The specific effect is as follows,1).The proportion of TNF-? positive cells,the expression of TNF-? protein, and the expression of TNF-? m RNA in LBP each group was lower than the model group, the difference was statistically significant(P <0.01 or P <0.05);2). The proportion of Bcl-2 positive cells,the expression of Bcl-2 protein, the expression of Bcl-2 m RNA in LBP each group was higher than the model group, the difference was statistically significant(P <0.01 or P <0.05).Conclusion 1. Prophylactic use of lycium barbarum polysaccharides can alleviate neurological deficits(this effect only gradually showed after 12 h of ICH), brain edema, oxygen free radicals injury and neuronal apoptosis.2. The inhibition mechanism of lycium barbarum polysaccharides on ICH secondary neuronal apoptosis may be completed by inhibit the expression of PAR-1, or by intervene the extrinsic and intrinsic apoptosis pathways.