Combination of cell metabolomics and pharmacology: A novel strategy to investigate the neuroprotective effect of Zhi-zi-chi decoction

Zhi-zi-chi Decoction(ZZCD), a traditional Chinese medicine formula, has been reported its potential protective effect on psychological sub-health diseases. However, there still remains a lack of molecular mechanism interpretation. This study was aimed at investigating the mechanism of glutamate-induced toxicity in PC12 cells and the neuroprotective effect of ZZCD based on a novel strategy of the combination of cell metabolomics and pharmacology. The PC12 cells were treated with glutamate to simulate neurotoxic cell model. Gas chromatography coupled with mass spectrometry based on cell metabolomics approach was performed to comprehensively investigate the molecular mechanism of glutamate-induced toxicity The cell viability and cytotoxicity analysis, the determination of glutathione reductase(GR), superoxide dismutase(SOD) and reactive oxygen species(ROS), apoptosis analysis and western blot analysis were performed to evaluate the neuroprotection of ZZCD. Forty metabolites were identified as potential biomarkers in model cells by principal components analysis(PCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA). Glutamate decreased the GR and SOD activities, increased the level of intracellular ROS, activated the apoptotic pathway, and induced the changes of energy metabolism, amino acid metabolism and lipid metabolism. In addition, the extract of ZZCD could reverse the disturbed metabolic pathways by regulating those potential biomarkers and exerted anti-oxidation and anti-apoptosis. ZZCD has neuroprotective effect and the novel strategy can be applicable for other traditional Chinese medicine formulas.