Neuroprotective effect of 7,8-dihydroxyflavone on cerebral hemorrhage in mice by regulating the TrkB/BDNF signal pathway
Objective To investigate the neuroprotective effect of 7,8-dihydroxyflavone(7,8-DHF)on cerebral hemorrhage in mice by regulating the tyrosine kinase receptor B(TrkB)/brain derived neurotrophic factor(BDNF)signal pathway.Methods C57BL/6 mice were injected with bacterial collagenase V Ⅱ to establish cerebral hemorrhage model.The mice were randomly grouped into model group,control group(5 mg·kg-1 7,8-DHF),experimental group(1 mg·kg-1 K252a),and combined group(5 mg·kg-1 7,8-DHF+1 mg·kg-1 K252a),mice injected with normal saline were used as sham-operation group,with 10 mice in each group.After the treatment,the mice were scored for neurological function by Garcia method,brain water contents of the brain tissue were detected by the dry and wet weight method,the blood brain barrier permeability was examined using the Evans blue method,the neuronal apoptosis was detected by TUNEL method,and the protein expression levels of TrkB,phosphorylated TrkB(p-TrkB)and BDNF were detected by Western blot.Results The neurological function scores of control,experimental,combined,model and sham-operation groups were(15.47±1.55),(7.23±0.73),(10.55±1.06),(10.45±1.05)and(16.12±1.62)points;the brain water contents were(62.88±2.19)%,(83.77±3.11)%,(72.71±2.59)%,(72.88±2.61)%and(59.64±2.06)%;the Evans blue contents were(3.26±0.36),(16.23±1.63),(8.78±0.88),(9.47±0.95)and(1.02±0.11)μg·g-1;neuronal apoptosis rates were(9.82±0.99)%,(39.88±3.99)%,(22.15±2.24)%,(25.71±2.58)%and(6.46±0.65)%;p-TrkB/TrkB ratios were 1.01±0.11,0.21±0.03,0.48±0.05,0.49±0.05 and 1.03±0.11;the protein expression levels of BDNF were 1.15±0.12,0.18±0.02,0.46±0.05,0.42±0.05 and 1.18±0.12,respectively.The above indexes of sham-operation,control and experimental groups were compared with those of model group,and the above indexes of control and experimental groups were compared with those of combined group,the differences were statistically significant(all P<0.05).Conclusion 7,8-DHF has neuroprotective effect on mice with intracerebral hemorrhage,and its mechanism may be related to the activation of TrkB/BDNF signal pathway.