Effects Of Baicalein On Motor Function Recovery And Related Factors Of Axonal Regeneration And Synaptic Plasticity In Mice After Cerebral Ischemia

Objective: Cerebrovascular disease has been one of the major diseases which have greatly threatened human health.Stroke has caused severe nerve function defection and physical disabilities.Due to limited nerve function repair effect,related findings about post-stroke axonal regeneration and synaptic plasticity which is closely related to the recovery of nerve function have received more and more attention at present.Baicalein,an extract from traditional Chinese medicine radix scutellariae,has a variety of activities such as anti-inflammatory,anti-oxidant and anti-apoptosis.But baicalein's role in motor function recovery has been still unknown.Factors which are related to synaptic plasticity and motor function recovery after stroke have been widely studied,such as GAP-43,BDNF,PSD95 and SYP.The present study investigated whether delayed treatment with baicalein had effect on experimental mice motor function and factors about axonal regeneration and synaptic plasticity.The research attempted to provide new targets for treatment of stroke by exploring its possible mechanism.Methods: Experimental model using male C57BL/6 mice were made by permanent occlusion of the distal middle cerebral artery with inustion.Mice were randomly divided into four groups: sham-operated group(Sham),mice subjected to cerebral ischemia(MCAO),mice subjected to cerebral ischemia with 30 mg/kg baicalein(Baic-L),mice subjected to cerebral ischemia with 100 mg/kg Baicalein(Baic-H).Mice in the Baic-L and Baic-H groups were intragastric administration once a day for fourteen days.The Rotarod behavioral score was first achieved 24 hours after the establishment of MCAO model from all mice and then scored on day3,7,14.Results: Baicalein could improve motor function of experimental mice.Results showed that the three groups were in a balanced baseline levels on the first day and the third day after the establishment of MCAO model(P> 0.05).The Baic-H group in comparison with the Baic-L group or the MCAO group had statistical difference and improved motor function on day 7(P< 0.05).The Baic-L group compared to the MCAO group showed no significant change on day 7(P> 0.05).The score of the Baic-H group significantly increased compared to the other two groups on day 14(P< 0.05).Our results showed that the level of GAP-43 protein in the Baic-H group compared to the MCAO group or the Sham group significantly increased on day 7(P< 0.05).The level of GAP-43 protein in the Baic-H group was also found in higher level than the Sham group on day 14(P< 0.05).There was no significant difference in the expression of GAP-43 protein between the Baic-H group and the MCAO group on day 14(P> 0.05).Up-regulation of the levels of BDNF,PSD95 and SYP proteins in the Baic-H group were obvious compared to the MCAO group or the Sham group on day 7(P < 0.05).The expression of BDNF,PSD95 and SYP proteins were upregulated in the MCAO group compared to the Sham group(P< 0.05).Conclusions: The present study showed that baicalein could increase score and improve motor function of experimental cerebral ischemia mice,in addition,baicalein also could increase the levels of GAP-43,BDNF,PSD95 and SYP proteins and may be involved in the regulation of axonal regeneration and synaptic plasticity.