Study on the effect and mechanisms of timosaponin B-Ⅱ on antidepressant

Key words: 
• depression /
• timosaponin /
• mechanism

Abstract: Objective To study the effect and mechanisms of timosaponin B-Ⅱ on depression. Methods The tail suspension test(TST),forced swimming test(FST),open field activity test(OFA),APO-induced synergistic action test,inhibiting reuptake of monoamine neurotransmitters and monoamine oxidase inhibitor(MAOI) test,yohimbine-induced lethality test and 5-HTP-induced head-twitch test were carried out to examine the antidepressant effect and mechanisms of timosaponin B-Ⅱ in rats.Immobility duration in FST and TST,spontaneous activity frequency in OFA,the stereotyped behaviors scores in APO-induced synergistic action test,and mortality in the other tests were observed. Results Timosaponin B-Ⅱ(100、150mg/kg) could effectively shorten the immobility time in TST and FST,but all dosages showed no significant effect on the spontaneous activity frequency in OFA.Timosaponin B-Ⅱ(150 mg/kg) significantly increased the rate of death of injecting dopamine,but had no obvious effect on the inhibiting reuptake of NE.Timosaponin B-Ⅱ(100、150 mg/kg) enhanced the apomorphine-induced stereotypy remarkably,which with statistically significant differences(P<0.05),and increased the head-twitch response evoked by 5-HTP,but had no effect on the yohimbine toxicity. Conclusion Timosaponin B-Ⅱhas significant antidepressant effect which may be related to the potentiation of brain 5-HT nerve system and DA nerve system.