Metabolic mechanism of a polysaccharide from Schisandra chinensis to relieve chronic fatigue syndrome

• Polysaccharide (SCP) from Schisandra chinensis fruit was characterized.
• Therapeutic mechanism of SCP in Chronic Fatigue Syndrome rats was investigated.
• Six metabolites and two metabolic pathways were identified as biomarkers and metabolic pathways indicating the effect of SCP.

Schisandra chinensis fruits are a famous traditional Chinese medicine to treat all kinds of fatigue. This study aimed to investigate the therapeutic effect and metabolic mechanism of a polysaccharide (SCP) from Schisandra chinensis fruits on chronic fatigue syndrome (CFS). SCP was isolated and the physicochemical properties were analyzed. A CFS model of rats was established and the urinary metabonomic studies were performed using gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) in combination with multivariate statistical analysis. The results showed that SCP is a protein-bound polysaccharide. The amino acid composition of SCP consisted of 12 amino acids. The growth and the behaviors of the rats in the CFS model group were worse than those in the control group and improved after SCP treatment. Analysis of the GC-TOF-MS revealed that twelve metabolites were significantly changed, and six metabolites were oppositely and significantly changed after the SCP treatment. The TCA cycle metabolic pathways and the alanine, aspartate and glutamate metabolism were identified as significant metabolic pathways involved with SCP. The therapeutic mechanism of SCP against CFS was partially due to the restoration of these disturbed pathways.