The effect of metformin on lipid disorders as measured by nuclear magnetic metabolomics and metabolic flux analysis / 药学学报

Studies have found that metformin is not only the preferred drug for lowering blood sugar, but also shows lipid-lowering and weight-loss effects. The purpose of this study was to use a hyperlipidemia hamster model to investigate the lipid-lowering effect of metformin and its effect on important metabolic pathways in lipid metabolism disorders. Fifty golden hamsters were divided into a control group, a model group, metformin high- and low-dose groups, and a simvastatin group. A high-fat diet was fed for 1 week to create the model, and then drug was administered for 11 weeks with the high-fat diet. Serum was taken for measurement of blood lipid and blood glucose at 2, 6, and 9 weeks after administration, and at weeks 3, 5, and 9 feces and urine were collected for 1H NMR metabolomics tests. After 11 weeks of intravenous injection of [U-13C6] glucose, serum was collected for a 13C NMR metabolic flux test. The results showed that the administration of metformin can significantly reduce blood lipids and glucose levels and can significantly affect metabolic pathways such as sugar metabolism, lipid metabolism, ketone metabolism, amino acid metabolism, and intestinal flora metabolism. The results of the metabolic flux analysis showed that the high-fat diet reduced the metabolism of tricarboxylic acids by 37.48%. After administration of low and high doses of metformin the metabolism of tricarboxylic acid increased by 98.14% and 143.10%, respectively. After administration of simvastatin tricarboxylic acid metabolism increased by 33.18%. The results indicate that metformin has a significant effect on promoting energy metabolism. This study used a combination of metabolomics and metabolic flow to explore the effect of metformin on lipid metabolism disorders and quantifies changes in the key pathway of energy metabolism-the tricarboxylic acid cycle. This study provides useful information for the study of the efficacy and mechanism of metformin, as well as a practical technical method for the screening of lipid-lowering drugs based on a hamster model.

An insoluble polysaccharide from the sclerotium of Poria cocos improves hyperglycemia, hyperlipidemia and hepatic steatosis in ob/ob mice via modulation of gut microbiota / 中国天然药物

Metabolic syndrome characterized by obesity, hyperglycemia and liver steatosis is becoming prevalent all over the world. Herein, a water insoluble polysaccharide (WIP) was isolated and identified from the sclerotium of Poria cocos, a widely used Traditional Chinese Medicine. WIP was confirmed to be a (1-3)-β-D-glucan with an average Mw of 4.486 × 10 Da by NMR and SEC-RI-MALLS analyses. Furthermore, oral treatment with WIP from P. cocos significantly improved glucose and lipid metabolism and alleviated hepatic steatosis in ob/ob mice. 16S DNA sequencing analysis of cecum content from WIP-treated mice indicated the increase of butyrate-producing bacteria Lachnospiracea, Clostridium. It was also observed that WIP treatment elevated the level of butyrate in gut, improved the gut mucosal integrity and activated the intestinal PPAR-γ pathway. Fecal transplantation experiments definitely confirmed the causative role of gut microbiota in mediating the benefits of WIP. It is the first report that the water insoluble polysaccharide from the sclerotium of P. cocos modulates gut microbiota to improve hyperglycemia and hyperlipidemia. Thereby, WIP from P. cocos, as a prebiotic, has the potential for the prevention or cure of metabolic diseases and may elucidate new mechanism for the efficacies of this traditional herbal medicine on the regulation of lipid and glucose metabolism.

Progress in metabolomics research of diabetes / 药学学报

Diabetes is a metabolic disease with an extremely high incidence in China. In parallel with an increased incidence yearly, the population of diabetes is showing a trend towards younger age. Therefore, it is urgent to carry out research on diabetes in order to develop strategy for prevention. In recent years, metabolomics has made significant progress in the study of biomarkers, pathogenesis, early diagnosis and prognosis, and evaluation of drug efficacy in diabetes. However, limited by metabolomics technology and the complexity of diabetes research, metabolomics in the diabetes research remains challenging. We summarize the progress and prospect the future development of metabolomics in the diabetes research.

Metabolic profile of feces and intestinal contents in hyperlipidemic hamster / 药学学报

The study was designed to explore the influence of high-fat diet on the metabolism profile of feces and intestinal contents of golden hamster to provide new information for the mechanism of drug action. Twelve golden hamsters fed with high-fat diet and twelve golden hamsters fed with normal diet were used as model group and control group, respectively. Serum samples were collected from the normal group and the model group at 2 weeks, 4 weeks and 8 weeks after the induction of high-fat diet. Serum biochemical parameters were measured in the control and model groups. The levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) levels in model group were higher than the control group. After 8 weeks, the feces and intestine contents were taken. The intestine was divided into four sections:jejunum, ileum, cecum and colon. The changes of endogenous metabolites in intestinal contents were analyzed by 1H NMR based metabolomics combined with multivariate statistical analysis to find the significant differences in metabolites. The metabolic profiles of hyperlipidemia model group and control group were significantly distinguished by the othorgonal partial least squares-discriminate analysis, (OPLS-DA). Compared with the control group, the endogenous metabolites in feces such as amino acids, fatty acids, tricarboxylic acid cycle intermediates and nucleotides related to intestinal microflora were changed significantly (PP<0.05). The data suggest that the intestinal microflora plays an important role in the development of hyperlipidemia in golden hamsters from the molecular level of metabolites. This result provides useful information for the clinical treatment of hyperlipidemia and development of hyperlipidemia drug.

Investigation of Single-stranded Deoxyribonucleic Acid Translocation Through α-Hemolysin Nanopore with Ionic Liquid Supporting Electrolytes / 分析化学

Due to the difference in spatial configuration and charge of the bases in a DNA molecule, characteristic translocation current pulses through a single nanopore could be obtained. This could become the basis of DNA sequencing method. However, due to the fast translocation speed (sub-micro seconds) and the small current change (about pA), it is still a challenge to obtain the accurate molecular substructure with present electronic techniques. In this work, in order to control the translocation behavior of ssDNA, two kinds of ionic liquids with high viscosity and conductivity were introduced to establish a viscosity gradient with the α-hemolysin single nanopore interface and the acidity of the solution was optimized. The trans chamber contained pure BmimPF6 and the cis chamber contained 1 mol/ L BmimCl and 10 mmol/ L Tris-HCl ( pH 5. 5 ). Preliminary experiment results under this electrolyte configuration showed that poly ( dC) 15 , poly ( dC) 15 , poly(dC) 30 and poly(dC) 50 exhibited obvious long duration pulses with high current suppression ratio. The blocking depth reached more than 95％ of long blocking events. The duration time of long blocking events prolonged to tens or hundreds of milliseconds. Meanwhile, the peak-peak of baseline noise was reduced by about 30％ .

Leojaponic acids A and B, two new homologous terpenoids, isolated from Leonurus japonicus / 中国天然药物

The present study aimed at isolation and purification of the bioactive terpenoids from the herb of Leonurus japonicus by chromatographic separations such as silica gel, sephadex LH-20 and C18 reversed phase silica gel, as well as preparative HPLC. As a result, leojaponic acids A (1, C17H24O4) and B (2, C18H26O4), two homologous terpenoids, together with (-)-loliolide (3), 1-(3-ethylphenyl) ethane-1, 2-diol (4) and dibutyl phthalate (5), were isolated from the EtOH extract of L. japonicus. All the chemical structures of the isolates were elucidated on the basis of 1D and 2D NMR analyses. Compounds 1 and 2 were new terpenoids, and Compounds 3 and 4 were isolated and identified for the first time from this plant. In addition, the α-glucosidase and tyrosinase inhibitory activity of the new compounds were evaluated.

Hypoplasia of cochlear nerve foramen:CT findings / 中华放射学杂志

Objective To observe the CT findings of hypoplasia of cochlear nerve foramen. Methods CT findings of cochlear nerve foramen were observed in 50 volunteers (100 ears)and in 9 cases with hypoplasia of cochlear nerve foramen.The width of the bony canal for the cochlear nerve were measured in both groups.Results The fissure in the cribriform area were seen in every volunteers.The width of the bony canal for the cochlear nerve was (2.32?0.25)mm in normal group.The stenosis of cochlear nerve foramen were shown in 9 cases (10 ears),the lacking of fissure in the cribriform area were seen in 8 ears, while the fissure were shown in 2 cases.The stenosis of internal auditory canal was shown in 4 cases. Abnormality of vestibule and horizontal semicircular canal was shown in one case.The maximum value of the width of the bony canal for the cochlear nerve was 1.5mm,the minimum value was 0.9 mm.Conclusions The typical CT findings of hypoplasia of cochlear nerve foramen were stenosis of cochlear nerve foramen,the lacking of fissure in the cribriform area and cochlear nerve foramen without helix shape.The hypoplasia of cochlear nerve foramen may be a subtype of cochlear dysplasia.