An integrated plasma and urinary metabonomic study using UHPLC–MS: Intervention effects of Epimedium koreanum on ‘Kidney-Yang Deficiency syndrome’ rats

Abstract

A metabonomic strategy based on UHPLC–MS with principal component analysis was developed to investigate the intervention effects of Epimedium koreanum on metabolism characters of ‘Kidney-Yang Deficiency syndrome’ rats. The rats were injected intraperitoneally hydrocortisone once daily for 15 days to simulate ‘Kidney-Yang Deficiency syndrome’ and then administered orally E. koreanum extract once daily for the following 15 days. Plasma and urine samples before hydrocortisone injection, on day 15 of hydrocortisone injection and on days 3, 6, 9, 12, 15 exposed to E. koreanum extract were collected. Significant metabolic disorders were observed in ‘Kidney-Yang Deficiency syndrome’ rats and sixteen potential biomarkers were identified. The disturbed plasma levels of phenylalanine, tryptophan, cholic acid, lysophosphatidylcholines and urinary levels of phenylalanine, hippurate, phenylacetylglycine, N2-succinyl-l-ornithine, creatinine, α-ketoglutarate, citrate, phenol sulfate, indoxyl sulfate, cresol sulfate in model rats were gradually restored to normal after administration of E. koreanum extract, which indicated that E. koreanum had time-dependent recovering effects via regulating oxidant–antioxidant balance, amino acid metabolism, lipid metabolism, energy metabolism, and gut microflora. This work highlights that metabonomics is a promising tool for studying the essence of Chinese medicine's syndrome theory and the action mechanism of traditional Chinese medicine, and provides scientific and reasonable information on safety and efficacy of traditional Chinese medicine.