Improvement effect of extract of St.John's wort tabIets on fear and anxiety behavior of post-traumatic stress disorder model mice / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To investigate the effect of extract of St.John's wort tablets (ESJWT) on post-traumatic stress disorder (PTSD) in a mouse model and explore possible avenues for the treat-ment of PTSD.METHODS Forty-eight C57BL/6 male mice were randomly divided into 4 groupsnormal control group, model group, sertraline and ESJWT treatment groups, with 12 mice in each group. Except the normal control group, all the mice were treated with fifteen intermittent inescapable foot-shocks (intensity0.8 mA;interval10 s;duration10 s)for 2 d.Sertraline 15 mg·kg-1and ESJWT 25 mg·kg-1 were ig given one hour before foot-shocks repectively,once a day,for 18 d.Then,contextual freezing and fecal pellet were tested on the 3rd,8thand 15thdays.In addition,open field test,elevated plus maze test and staircase test were performed on the 16th, 17thand18thdays, respectively. Here, the day mice were subjected to short foot-shocks was defined as the 1stday.The serum contents of norepinephrine (NE) and 5-hydroxytryptamine (5-HT) were evaluated using ELISA after behavior tests. RESULTS Compared with normal control group, the freezing time and the number of fecal pellet in model group were significantly increased(P<0.01).Meanwhile,the time and number of entries into the central open field and open arm were decreased(P<0.01).The above experiments indicated that the mouse model of PTSD was established successfully. Compared with model group, both sertraline and ESJWT extract showed anti-PTSD effect, with the decreased percentage of freezing time (P<0.05, P<0.01). ESJWT extract treatment also reduced the amount of fecal pellet(P<0.01).However,no significant changes of the contents of NE and 5-HT in any group were seen.CONCLUSION ESJWT has anti-PTSD effect in the mouse model,which might be used for the treatment of PTSD.