| Metabonomics is defined as "the quantitative measurement of the multiparametric time-related metabolic responses of a complex system to a pathophysiological intervention or genetic modification". Metabolome is the result of whole expression of proteome, transcriptome and genome which reflect the biochemical status of tissues directly. It is very important for the illustration of the complicated life systems because of the sensitive response of the changes of the physiological and pathological status of the life. Metabonomics has been widely used in the research of pharmacology and biological sciences. The study on complicated disease including metabolic diseases is very significant for their diagnosis, prevention and drug intervention.Type 2 diabetes mellitus also called non insulin dependent diabetes mellitus (NIDDM), is a metabolic disorder characterized by a chronic hyperglycemia. Type 2 diabetes mellitus, which accounts for approximately 90% of patients with diabetes has been described as an "epidemic" of contemporary society. It is reported that 130 million of patients with type 2 diabetes mellitus have been diagnosed in the world. In China, the number of diabetic patients exceeded 39.8 million by the year 2007, of which 93.7% belong to type 2 diabetes mellitus. The number is increasing along with the improvement of people’s living standards, aging and changes of life style.In this study, an experimental rat model which imitated the pathogensis of human type 2 diabetes mellitus has been established. Ultra-performance liquid chromatography/mass spectrometry and nuclear magnetic resonance technologies were applied to the metabolite profiling of serum, urinary and fecal samples from control, high fat diet and model of type 2 diabetic rats. Multivariate statistical analysis and pattern recognition were used for screening of potential biomarkers. The method was also applied in the action mechanism study of anti-diabetic drugs metformin, acarbose and mitiglinide.1. Experimental type 2 diabetic rat modelWistar rats after six-week high glucose and high fat diet feeding, were injected with STZ (30mg/kg) to induce type 2 diabetes mellitus. The result revealed that the fasting blood glucose was not significantly increased after six-week feeding of high glucose and high fat diet while the serum triglyceride level was significantly increased and insulin level decreased. It indicated that after six-week feeding of high glucose and high fat diet, the rats had been insulin resistant. After the injection of STZ, the fasting blood glucose was increased. Compared with literatures, our method has high model forming rate (80%) and low mortality rate.2. UPLC/MS analysis of serum metabolite profiles of type 2 diabetic rats pre-and after anti-diabetic drug administrationUPLC/MS method was developed for rat serum metabolite profiling study of control group, high fat diet group and model of type 2 diabetes group. Principal component analysis (PCA) and multivariate analysis were used for their clustering and biomarker searching. The result demonstrated that the three groups were successfully separated and serum 16:0 lysophosphatidylcholine (LPC),18:0 LPC,18:2LPC and phenylalanine were significantly increased in type 2 diabetic group. The method was applied for action mechanism study of three anti-diabeitc drugs, metformin, acarbose and mitiglinide. The results indicated that the three drugs can all decrease the level of LPC in serum of type 2 diabetic rats, which may be associated with their anti-oxidative stress function.3. UPLC/MS analysis of urinary metabolite profiles of type 2 diabetic rats pre-and after anti-diabetic drug administrationUPLC/MS method was developed for rat urinary metabolite profiling study of control group, high fat diet group and model of type 2 diabetes group. PCA and multivariate analysis were used for their clustering and biomarker searching. The result demonstrated that the three groups were successfully separated and creatinine, citrate, hippurate and phenylacetylglycine levels in urine were significantly decreased in type 2 diabetic group while the levels of chenodeoxycholic acid, deoxycholic acid and cholic acid were increased. The method was applied to the action mechanism study of three anti-diabeitc drugs, metformin, acarbose and mitiglinide. The results indicated that the three drugs can improve the metabolism of these metabolites in urine of type 2 diabetic rats, which may be associated with bile acids metabolism, energy metabolism and gut microflora metabolism.4. UPLC/MS analysis of fecal metabolite profiles of type 2 diabetic rats pre-and after anti-diabetic drugs administrationUPLC/MS method was developed for fecal metabolite profiling study of control group, high fat diet group and model of type 2 diabetes group. PCA and multivariate analysis were used for their clustering and biomarker searching. The results demonstrated that the three groups were successfully separated and ursodeoxycholic acid, cholic acid and phenylalanine in feces were significantly increased in type 2 diabetic group. The method was applied to the action mechanism study of three anti-diabeitc drugs, metformin, acarbose and mitiglinide. The results indicated that the three drugs can improve the metabolism of these metabolites in feces of type 2 diabetic rats, which may be associated with cholesterol metabolism and nutrition metabolism.5.1H NMR analysis of urinary metabolite profiles of type 2 diabetic rats pre-and after anti-diabetic drugs administrationAn 1H NMR method was developed for rat urinary metabolite profiling study of control group, high fat diet group and type 2 diabetic group. PC A and multivariate analysis were used for their clustering and biomarker searching. The result demonstrated that the three groups were successfully separated and glucose and taurine in urine were significantly increased in type 2 diabetic group while citrate, creatinine, lactate and acetate were decreased. The use of both LC/MS and 1H NMR results in the collection of complementary data on biomarkers, which is helpful for further understanding of the pathogenesis mechanism of type 2 diabetes.6. UPLC/MS analysis of plasma metabolite profiles of healthy volunteers pre-and after the administration of metforminThe established UPLC/MS method was applied to plasma metabolite profiling study of 20 healthy volunteers pre-and after the administration of metformin. The result demonstrated that the method can successfully differentiate the two groups and the biomarkers found were same as those achieved in rat model. The result suggests the method can be applied in clinical study. |
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