Morus alba L. water extract changes gut microbiota and fecal metabolome in mice induced by high-fat and high-sucrose diet plus low-dose streptozotocin.

Gut microbiota plays a key role in the pathophysiology of type 2 diabetes mellitus (T2D). Mulberry leaf has a hypoglycemic effect, but the potential mechanism is not fully understood. This study aimed to explore the influences and potential mechanisms of mulberry leaf water extract (MLWE) intervention on mice with T2D induced through a high-fat and high-sucrose diet combined with streptozotocin by the combination of fecal metabolomics and gut microbiota analysis. Results showed that MLWE could decrease fasting blood glucose and body weight while ameliorating lipid profiles, insulin resistance, liver inflammation, and the accumulation of lipid droplets in T2D mice. MLWE could reverse the abundances of the phyla Actinobacteria and Bacteroidetes and the ratio of Firmicutes/Bacteroidetes, and increase the abundances of the phyla Cyanobacteria and Epsilonbacteraeota in the feces of T2D mice. The abundances of genera Alloprevotella, Parabacteroides, Muribaculaceae, and Romboutsia in the feces of T2D mice could be reversed, while Oscillatoriales_cyanobacterium and Gastranaerophilales could be reinforced by MLWE supplementation. The levels of nine metabolites in the feces of T2D mice were improved, among which glycine, Phe-Pro, urocanic acid, phylloquinone, and lactate were correlated with Romboutsia and Gastranaerophilales. Taken together, we conclude that MLWE can effectively alleviate T2D by mediating the host-microbial metabolic axis.

Advances in detection and quantification of methylcytosine and its derivatives.

Methylation of the fifth carbon atom in cytosine is an epigenetic modification of deoxyribonucleic acid that plays important roles in numerous cellular processes and disease pathogenesis. Three additional states of cytosine, that is, 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine, have been identified and associated with the diagnosis and/or prognosis of diseases. However, accurate measurement of those intermediates is a challenge since their global levels are relatively low. A number of innovative methods have been developed to detect and quantify these compounds in biological samples, such as blood, tissue and urine, etc. This review focuses on recent advancement in detection and quantification of four cytosine modifications, based on which, the development, diagnosis, and prognosis of diseases could be monitored through non-invasive procedures.

Metabolomics Study of Metabolic Changes in Renal Cells in Response to High-Glucose Exposure Based on Liquid or Gas Chromatography Coupled With Mass Spectrometry.

Diabetic nephropathy (DN) is one of the most serious microvascular complications and the leading causes of death in diabetes mellitus (DM). To find biomarkers for prognosing the occurrence and development of DN has significant clinical value for its prevention, diagnosis, and treatment. In this study, a non-targeted cell metabolomics-based ultra-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry and gas chromatography coupled with mass spectrometry was developed and performed the dynamic metabolic profiles of rat renal cells including renal tubular epithelial cells (NRK-52E) and glomerular mesangial cells (HBZY-1) in response to high glucose at time points of 12 h, 24 h, 36 h, and 48 h. Some potential biomarkers were then verified using clinical plasma samples collected from 55 healthy volunteers, 103 DM patients, and 57 DN patients. Statistical methods, such as principal component analysis and partial least squares to latent structure-discriminant analysis were recruited for data analyses. As a result, palmitic acid and linoleic acid (all-cis-9,12) were the potential indicators for the occurrence and development of DN, and valine, leucine, and isoleucine could be used as the prospective biomarkers for DM. In addition, rise and fall of leucine and isoleucine levels in plasma could be used for prognosing DN in DM patients. Through this study, we established a novel non-targeted cell dynamic metabolomics platform and identified potential biomarkers that may be applied for the diagnosis and prognosis of DM and DN.

Predictive metabolic signatures for the occurrence and development of diabetic nephropathy and the intervention of Ginkgo biloba leaves extract based on gas or liquid chromatography with mass spectrometry.

Diabetic nephropathy (DN) is one of the leading causes of death in diabetes mellitus (DM). Early warning and therapy has significant clinical value for DN. This research sought to find biomarkers to predict the occurrence and development of DN and the intervention of Ginkgo biloba leaves extract (GBE) by quantifying fatty acids, amino acids, and nucleosides and nucleobases in rat plasma. Samples were respectively collected at the weekend of 5-10 weeks after diabetic rats induced by streptozotocin were defined. Plasma fasting blood-glucose, kidney index, blood urea nitrogen, creatinine, urine albumin excretion and ultrastructural morphology of kidney were measured or observed. Fatty acids, amino acids and nucleosides and nucleobases in rat plasma were analyzed by gas chromatography or liquid phase chromatography and mass spectrometry, respectively. From the biochemical index and morphological change of kidney, the rats from the 5th to 7th week were in the stage of DM while from the begin of 8th week the rats were suggested in the early stage of DN. The results of quantitative metabolomics showed that 16 differential metabolites were related to the progression of DN, and oleic acid, glutamate and guanosine might be the potential biomarkers of kidney injury. 14 differential metabolites were related to GBE against the progression of DN, while oleic acid and glutamate might be the potential biomarkers of GBE against kidney injury. Those findings potentially promote the understanding of the pathogenic progression of DN and reveal the therapeutic mechanism of GBE against DN.

Off-line two-dimensional liquid chromatography coupled with diode array detection and quadrupole-time of flight mass spectrometry for the biotransformation kinetics of Ginkgo biloba leaves extract by diabetic rat liver microsomes.

Ginkgo biloba leaves extract (GBE), one of the most widely used traditional Chinese medicines worldwide, can be used for the treatment of diabetes mellitus (DM). However, its biotransformation in liver is not fully known under the state of DM. In this study, an off-line hydrophilic interaction × reversed-phase two-dimensional liquid chromatography (HILIC × RP 2D-LC) system coupled with diode array detection (DAD) and quadrupole time-of-flight mass spectrometry (q/TOF-MS) was established for the qualification and quantification of the biotransformation of GBE in normal and diabetic rat liver microsomes (RLMs). 6 metabolites were tentatively identified according to the exact molecular weights and the characteristic fragment ions provided by q/TOF-MS data. The results of metabolic stability showed that the metabolic ratio of four target compounds including quercetin, genistein, kaempferol and isorhamnetin in diabetic RLMs were significantly enhanced when comparing with normal RLMs. The results of enzyme kinetics showed that compared with normal RLMs, the Michaelis-Menten constant (Km) value of genistein was obvious increased while its maximal velocity (Vmax) and intrinsic clearance (CLint) values were significantly decreased by diabetic RLMs, and the Vmax and CLint values of kaempferol and isorhamnetin were notably enhanced while their Km values were markedly reduced. For the half-time (t1/2) values of four target compounds and the Km, Vmax and CLint values of quercetin, there were not statistically significant changes between normal and diabetic RLMs. The results suggest that the developed off-line 2D LC-DAD-q/TOF-MS method is an easy and accurate approach for the study of GBE biotransformation in RLMs and may provide the essential data for further pharmacological and clinical studies of GBE.