ABSTRACT
The purpose of this study is to explore depression metabolic markers in rat hippocampus and to investigate the anti-depressant effect of genipin and its mechanisms using nuclear magnetic resonance (NMR) metabonomics. Chronic unpredictable mild stress (CUMS) procedure was conducted to establish the depressive rat model. At the beginning of the third week, genipin low dose (25 mg x kg(-1)), middle dose (50 mg x kg(-1)), high dose (100 mg x kg(-1)), and venlafaxine (50 mg x kg(-1)) were given to the CUMS rats separately once daily for two weeks except control and model groups. Rat hippocampus was analyzed by 1H NMR based metabonomics after drug administration for 2 weeks. Significant differences in the metabolic profile of rat hippocampus of the CUMS treated group and the control group were observed with metabolic effects of CUMS including decreasing in glycine and N-acetylaspartate, increasing in inositol, glutamate, lactate, glutamine, taurine and alanine. Genipin showed ideal antidepressive effects at a dose of 50 mg x kg(-1) in rats, decrease of inositol, glutamate, lactate, alanine were observed, while glycine and N-acetylaspartate were increased. Important influence has been found on normal nervous system function of these significant changed metabolites, which suggests that the antidepressant effect of genipin may be played by enhancing the activity of neurons in hippocampus, repairing and improving the function of the neuron. The metabonomics approach is an effective tool for the investigation of the anti-depressant effect and pharmacologic mechanisms of genipin.