ABSTRACT
The purpose of this study was to understand the pharmacodynamic effect of Valeriana jatamansi extract in diarrhea predominant irritable bowel syndrome(IBS-D) rat model induced by maternal separation combined with three kinds of stress, and observe the changes of endogenous metabolites in feces after intervention to find potential biomarkers and related metabolic pathways. The animal model of IBS-D was established by maternal separation combined with restraint, ice swimming and tail clamping. The therapeutic effect of each dose group of V. jatamansi extract was evaluated in terms of abdominal withdrawal reflex pressure threshold, fecal water content and immobility time of forced swimming test. In addition, rat feces were collected for detection of metabolic profiles of small molecular metabolites with UPLC-LTQ-Orbitrap MS platform, so as to find the biomarkers of differential metabolism with multivariate statistical analysis methods such as principal component analysis(PCA) and orthogon partial least squares discrimination analysis(OPLS-DA). The results showed that as compared with the normal group, the threshold of abdominal withdrawal reflex pressure was decreased, the fecal water content was increased, and the immobility time of forced swimming test was prolonged in the model group. The results of fecal metabonomics showed that the levels of 39 metabolites were down-regulated and those of 37 metabolites were up-re-gulated. Further analysis showed that these metabolites were related to bile acid metabolism, unsaturated fatty acid metabolism, amino acid metabolism, ceramide metabolism and other metabolic pathways. This study proved that the extract of V. jatamansi had definite pharmacodynamic effect on IBS-D model rats, and the mechanism was discussed from the perspective of fecal metabonomics.