Metabolomic study of raw and bran-fried Atractylodis Rhizoma on rats with spleen deficiency

Atractylodis Rhizoma, a classical Chinese medicine, exhibits unambiguous therapeutic effect on spleen deficiency in China for decades. The aim of the present study was to explore the different effects on the composition and level of endogenous metabolites in rats with spleen deficiency after oral administration of raw and bran-fired Atractylodis Rhizoma, and to explain the mechanism of pharmacodynamic enhancement of the bran-fried Atractylodis Rhizoma from the perspective of metabolomics. With this purpose, spleen deficiency model was established by diet, excessive fatigue and bitter cold diarrhea. Then, Enzyme-linked immunosorbent assay (ELISA) was used to determine the contents of vasoactive intestinal peptide (VIP), Somatostatin (SS), substance P (SP) and succinodehydrogenase (SDH) in rats of each group, and to compare the contents of VIP, SS, SP and SDH among groups. UHPLC-Q-TOF-MS based metabolomics was adopted to analyze the plasma from spleen deficiency rats and control rats. Principle component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) were utilized to identify differences of metabolic profiles in rats among the control group and the model group；The OPLS-DA were used to analyze the effects of raw and bran-fried Atractylodis Rhizoma on the same metabolites. The results showed that compared with the control group, the contents of VIP, SS, SP and SDH in the plasma of model group decreased, which proved the success of the model group. Compared with model group, the contents of VIP, SS, SP and SDH in the plasma of raw and bran-fried Atractylodis Rhizoma increased, and the effect of bran-fried Atractylodis Rhizoma was better than that of raw Atractylodis Rhizoma. Metabolomics results showed that seventeen different metabolites of spleen deficiency were screened out in the plasma of rats with spleen deficiency compared with the control group. Among them, Nicotinic acid, Dihydrofolic acid, Pantetheine 4′-phosphate and Photophatidylcholine (PC) were the metabolites significantly associated with spleen deficiency, and bran-fried Atractylodis Rhizoma had better intervention and regulation. Through the analysis of metabolic pathways related to these different metabolites of spleen deficiency, and primarily involved in glucosamine metabolism, one carbon pool by folate and so on. This study showed that Atractylodis Rhizoma could provide satisfactory therapeutic effects on spleen deficiency and metabolomics study can be utilized to further understand the molecular mechanisms.