NMR-based Metabonomics Quantitative Hamsters Model Lipid Metabolism And Lipid Regulating Follow-up Study Of Drug Efficacy Evaluation

Hyperlipidemia and atherosclerosis are multifactorial diseases, and the main initiating factor of cardiovascular disease, myocardial infarction and stroke. Unfortunately, the complex pathophysiology of these diseases still remains largely unknown despite a decade of research. Traditionally, studies of hyperlipidemia utilize serum-or plasma-based biochemical assays and histopathological evaluation. However, thses index are limited to the description of the middle and late stages of these diseases, when the organic injury may have occurred. So, thses methods can’t be used for early diagnose and prevention. Besides, these methods have the limitions in the tracking-analysis of the progress of these diseases, drug treatment efficiency and its mechanism in the molecular level.Metabonomics, with its impressive and ever-increasing coverage of endogenous compounds, as well as its intrinsic high-throughput capacity, has been demonstrated to be a valuable approach to study the complex biological responses to chemical and physical perturbations at the metabolic level. Metabonomics analyses can offer an unbiased view of changes in metabolisms covering entire metabolic pathways for characterizing pathological states, as well as giving diagnostic information.Recently metabonomics is developing towards integration, quantification and standardization. The main issue of metabonomics research is the lack of quantitative analysis. To measure all endogenous metabolites in the quantitative way is the ultimate goal of metabonomics, which can provide a panorama view of the complicated sysytem. However, the current panorama analysis remain in metabolic fingerprint spectrum study due to the limitation of the present analytical technique, which may hamper the further study of complicated sysytem in depth. So the quantitative metabonomics is need, which can describe the biomarkers, metabolic cycles and even the systems in a more accurate way.In this study, we have investigated the progression of hyperlipidemia and atherosclerosis in a hamster model using1H-NMR-based metabolomics, including both the traditional metabolomic approach and quantitative metabolomics coupled with multivariate data analysis. Samples include plasma, urine and liver were collected at different time points during the progression of hyperlipidemia and atherosclerosis, and individual proton NMR spectra were visually and statistically assessed using multivariate analyses (MVA). Using the commercial software package Chenomx NMR suite,40endogenous metabolites in the plasma,80in the urine and60in the water-soluble fraction of liver extracts were quantified. NMR analysis of all samples showed a time-dependent transition from a physiological to a pathophysiological state during the progression of hyperlipidemia and atherosclerosis. Analysis of the identified biomarkers of hyperlipidemia suggests that significant perturbations of lipid and amino acid metabolism, as well as inflammation, oxidative stress and changes in gut microbiota metabolites, occurred following cholesterol overloading. Besides, the aged hyperlipidemic hamsters model were also constructed and evaluated by NMR-based metabonomics. The VLDL/LDL in plasma, triglycerides, free and esterified cholesterol in liver extract of aged hyperlipidemic hamsters were higher than the youth, which may indicate that the aged hamsters are more sensitive to the high-fat/high-cholesterol diet. The increased level of plasma glucose and descreased TCA intermediates including citrate, succinate and cis-aconitate of the aged hyperlipidemic hamsters may indicate the aberrant changes in glycolysis and the TCA cycle occurred. Furthermore, the evaluation systems of NMR-based metabonomics combined with traditional pharmacological studies for hypolipidemic compounds were constructed, estabolishing the foundation for providing a new research pattern to pharmacological studies. Emodin, curcumin, ursolic acid, quercetin and WS090508, WS090138have beneficial effect on the plasma metabolic profile of hyperlipidemic hamsters, indicating that these compounds can not only regulate the plasma lipid but also improve the plasma metabolic profile. Quantitative metabonomics substantially broaden the metabonomic coverage of hyperlipidemia and atherosclerosis, and depict the metabolic profile in more accurate way, which can enable us to observe the time-dependent changes of related cycles, enhance our understanding of the mechanism of these diseases and demonstrate the effectiveness of the NMR-based metabonomics approach to study such complex diseases.