Metabonomics Studt On Chemical Liver Injury And Liver Cancer

The liver is the largest and most metabolically complex organ in humans. It plays a major role in metabolism and has a number of functions in the body, including glycogen storage, decomposition of red blood cells, plasma protein synthesis, and detoxification. So it is important to investigate the disorder of metabolisms in liver disease. Acute liver injury is the beginning of the liver diseases emerging, developing to the liver function failure at last. It is therefore of vital importance to investigate the pathogenesy and alternative measures of acute liver injury.It is well known that the mouse model of acute liver injury has been shown to be very useful for investigating the mechanism of various kinds of liver diseases and evaluating the drugs for hepatitis. Several animal models of liver injury, such as carbon tetrachloride (CCl4), alcoholic induced injury liver, have been widely used in both pathological and pharmacological studies. On the basis of the animal experiment, we try to find feasible method to research the mechanism of liver cancer from a new angle. Liver cancer, generally means primary liver cancer (PLC), is one of the most common malignant tumors of liver representing one of the most serious human cancerous problems in the world. PLC represents the fifth leading deaths among the cancer worldwide, and the second in China. As a multi-factorical and polygenic condition, PLC has complex molecular mechanisms which are not well understood by biomedical scientists and pathologists. Metabonomics as a novel methodology arising from the postgenomics era will help us to explore the mechanism study of liver injury and liver diseases.In this study, we try to establish extraction and chromatography in hyphenation with mass spectrometry metabonomic technologies to investigate metabolic variations of the liver tissue samples. Meanwhile, we investigate metabolic variations in PLC patients, alcoholic-induced acute liver injury rats, CCl4-induced acute liver injury rats and the protective effect of diammonium glycyrrihizinate on CCl4-induced liver injury rats using metabonomic study.We have developed a simple and reliable analytical assay for low-molecular-weight metabolites in liver tissue samples. The ethyl chloroformate (ECF) derivatization, GC/MS-based and the trimethylsilylation (TMS) derivatization, Gas chromatography time-of-flight mass spectrometry (GC/TOFMS)-based liver tissue metabonomic analysis method was optimized, respectively. Perchloric acid and ethonal extraction of liver tissue sample is suit to the GC/MS analysis and chloroform/methanol/water system is in favour of GC/TOFMS analysis. The two method validations revealed a wide linearity range, good repeatability and acceptable recovery rate for the proposed method.Combination with biochemistry and histological research, we used ECF derivatization and GC/MS-based metabonomic analysis of urines and liver tissue samples to visualize significant alterations in metabolite expression patterns as a result of CCl4-induced metabolic responses. The in-depth study of these metabolite alterations also allowed several major metabolic pathways, such as the tricarboxylic acid (TCA) cycle and some amino acid metabolism, were closely associated with CCl4 toxicity. Meanwhile, we attempt to investigate the protective actions of diammonium glycyrrihizinate to CCl4-induced liver injury with the metabonomic analysis. It will help make for the whole appraisal of the medicine.Establishing the acut alcoholic liver injury model of rats, we used ECF derivatization and GC/MS-based metabonomic technique to observe the metabolite expression pattern change in the urines and liver tissue samples. The results above could offer a feasible method to understand the mechanism of alcoholic liver injury and provide the basis for further research of alcoholic liver disease. The similar separation results were obtained with urine and liver tissue metabolic profiles. After identification of metabolites significantly varied in the model rats, energy metabolism, methionine metabolism and some other amino acids metabolism were associated with alcoholic-induced acute liver injury.Urinary and serumal metabolite profiling of PLC patients investigated using derivatized GC/MS in conjunction with modern multivariate statistical techniques revealed drastic biochemical changes as evidenced by fluctuations of metabolites. After identification of urine metabolites significantly varied in the PLC patients, energy metabolism, tyrosine metabolism were associated with PLC morbidity. The similar separation results of serum metabomomics were obtained with urine metabolic profiles, which were carried to indicate that the increased levels of histidine and glycine, and the decreased level of alanine, serine, lysine, phenylalanine and tryptophane.These results suggests that our metabonomics method may play an important role in exploring the mechanism of CCl4 or alcohol-induced liver injury, evaluating pharmacodynamic action of medicine for acute liver injury, and digging the great potential of urine or serum metabolic profile in PLC diagnosis. Meanwhile, the tissue metabonomics provide a unique perspective of localized metabolic information to metabonomics research.