Metabolomic study of the protective effect of Gandi capsule for diabetic nephropathy

Diabetic nephropathy (DN) is the one of the leading causes of end-stage renal disease (ESRD) in clinical. However, it is still lack of accurate biomarkers and effective methods for diagnosing and curing DN. Therefore, there is an urgent need to develop a definite strategy for the identification of reliable and versatile biomarkers for risk assessment of DN and search for therapeutic approaches that can effectively attenuate DN progression. Treatment with Gandi capsule (GDC) not only decreased the levels of urinary albumin excretion, but also increased the levels of estimated glomerular filtration rate (eGFR), indicating that it produces a renal protective effect on diabetic nephropathy. Based on metabolomics investigation including UHPLC–MS analysis and multivariate statistical analysis, sixteen disordered metabolites were screened out and considered as potential biomarkers corresponding to DN, which were mostly improved and partially returned to normalcy in GDC treatment group. Therefore, it was suggested that GDC was a promising therapeutic agent against DN. The underlying mechanisms of GDC attenuating the development of DN may be improving abnormal metabolic disorders by retrieving the imbalance of glycine metabolism, tryptophan metabolism, valine, leucine and isoleucine degradation, purine metabolism, nitrotoluene degradation, phenylalanine metabolism, fatty acid metabolism, tyrosine metabolism and bile acid metabolism pathways. The data obtained in this study may provide key clues to enhance our understanding of the metabolic mechanism of DN and shed new insights into the therapeutic mechanism of GDC.