The effect of the Mongolian medicine modified Tabusen-2 on kidney-yang deficiency in rats based on metabolomics

We used metabolomics to investigate the ability of a traditional Mongolian medicine called modified Tabusen-2 (MT-2) to improve kidney yang deficiency (KYD) in rats. All animal experiments were conducted under the guidance and standards of the Medical Ethics Committee of Inner Mongolia Medical University. SD rats were divided into 6 groups of six rats: a normal group, a model group, Jinkuishenqi pill administration group (1.26 g·kg^-1), and MT-2 administration in high-, medium- and low-dose groups (1.512, 0.756, and 0.378 g·kg^-1). KYD was established by intramuscular injection of hydrocortisone (HC) and biochemical indicators and clinical characterization was used to confirm that KYD was established. All groups received intragastrically administered drug (Jinkuishenqi pill or MT-2) or saline. Serum from each group was collected after 8 weeks and analyzed by UPLC-Q-exactive-MS to measure various biochemical indicators. The biomarkers affected by MT-2 were identified and the metabolic pathways of KYD regulated by MT-2 were analyzed by metabolomic analysis. The results show that MT-2 can decrease serum creatinine (Cr) in KYD rats and significantly increase (P < 0.05) the content of thyroid stimulating hormone (TSH) and luteinizing hormone (LH). In serum samples, 38 biomarkers such as corticosterone, L-phenylalanine, and DL-tryptophan were measured as possible indicators for disease development in KYD rats. MT-2 lowered 18 biomarkers of KYD, including corticosterone, deoxycorticosterone, and L-phenylalanine, and altered 13 related metabolic pathways including phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism and steroid hormone biosynthesis, resulting in an overall improvement in KYD. MT-2 appears to be important in improving KYD in rats mainly by regulating metabolites such as amino acids, steroids and lipids.