Protective effect and mechanism of Xiaoyao San on lipopolysaccharide-induced hippocampal neurons injury

Abstract

To investigate the relationship between anti-depressant effect and hippocampal nerve growth of Xiaoyao San,the inflammatory model of hippocampal neuron was induced by lipopolysaccharide( LPS). The effect of Xiaoyao San serum( final concentration of4%,8%) on the cell proliferation activity was detected by immunofluorescence,the levels of BDNF and β-NGF in the supernatant of hippocampal neurons were detected by ELISA,and the expressions of BDNF,NGF,Trk B,Trk A and CREB mRNA in cell lysate of hippocampal neuron were detected by PCR. Western blot was used to detect the expressions of Trk B,CREB,p-CREB and SYP protein in cell lysate of hippocampal neuron,and to reveal the neuroprotective effect and mechanism of Xiaoyao San. The results showed that8% Xiaoyao San serum could significantly increase in Brdu/Neu N ratio( P<0. 01). 4%,8% Xiaoyao San serum could significantly improve the levels of BDNF and β-NGF in supernatant( P<0. 05 or P<0. 01),up-regulate the expression of BDNF,NGF,Trk B,Trk A,CREB mRNA and Trk B,p-CREB,SYP protein in cell lysate( P< 0. 05 or P< 0. 01). 8% Xiaoyao San serum could significantly increase CREB protein in cell lysate( P<0. 05),and elevate in p-CREB/CREB ratio( P<0. 01). All the above results indicate that Xiaoyao San has a certain protective effect on LPS induced hippocampal neuron injury,which suggests that the protective effect of Xiaoyao San is related to the promotion of hippocampal nerve growth,which is one of its antidepressant mechanisms.