The expression profiles of circular RNAs and competing endogenous RNA networks in intrahepatic cholangiocarcinoma.

Introduction: Intrahepatic cholangiocarcinoma (iCCA) is a heterogeneous entity with diverse etiologies, morphologies, and clinical outcomes, but our knowledge of its epidemiology and carcinogenesis is very limited. Materials and methods: The expression patterns of circRNAs were explored in iCCA tissues and corresponding adjacent normal ones, denoted by (iCCA) and (iCCAP), respectively, using high-throughput sequencing. Results: A total of 117 differential expressed (DE) circRNAs were identified. Based on the parental transcripts of circRNAs, these DE circRNAs were related to several important GO terms and were enriched in important pathways. Two circRNA-mediated ceRNA networks were constructed and many important metabolic pathways related to mRNAs were regulated by DE circRNAs via miRNAs. Conclusion: Our study revealed the DE circRNAs in the iCCA tissues compared with iCCAP ones, suggesting that circRNAs may play crucial roles in the pathogenesis of iCCA.

Posterior reversible encephalopathy syndrome with a special focus on seizures.

Posterior reversible encephalopathy syndrome (PRES) is a neurological disorder characterized by headache, seizures, confusion and visual disturbances, as well as potentially reversible neuroimaging findings in most patients after proper treatment. Seizures is one of the most common clinical presentations of PRES. This review summarizes the potential pathophysiology and clinical features of PRES, as well as a multimodal approach to imaging and also briefly discusses the phenomenon of seizures in paediatric population.

Comparative effect of ciprofloxacin and moxifloxacin on the modulation of bile acid profiles and gut microbiota in rats

Abstract Fluoroquinolones are an important class of antimicrobial agents to manage infectious diseases. However, knowledge about how host bile acids are modified by fluoroquinolones is limited. We investigated and compared the impact of fluoroquinolones on circulating bile acid profiles and gut microbiota from in vivo studies. We administered ciprofloxacin (100 mg/kg/day) or moxifloxacin (40 mg/kg/day) orally to male Wistar rats for seven days. Fifteen bile acids (BAs) from the serum and large intestine were quantified by HPLC-MS/MS. The diversity of gut microbiota after ciprofloxacin and moxifloxacin treatment was analyzed using high-throughput, next-generation sequencing technology. The two fluoroquinolone-treated groups had different BA profiles. Ciprofloxacin significantly reduced the hydrophobicity index of the BA pool, reduced secondary BAs, and increased taurine-conjugated primary BAs in both the serum and large intestine as compared with moxifloxacin. Besides, ciprofloxacin treatment altered intestinal microbiota with a remarkable increase in Firmicutes to Bacteroidetes ratio, while moxifloxacin exerted no effect. What we found suggests that different fluoroquinolones have a distinct effect on the host BAs metabolism and intestinal bacteria, and therefore provide guidance on the selection of fluoroquinolones to treat infectious diseases.

Mechanism of inhibiting proliferation of tumor cells by a new tetrahydroisoquinoline compound SYT-1 / 药学学报

In this study, we investigated the inhibitory effect of SYT-1, a new compound of tetrahydroisoquino-line, on tumor cell proliferation and underlying mechanisms. Cell counting kit-8 (CCK-8) method was used to detect cell proliferation; clone formation experiment was used to detect cell clone formation ability; JC-1 probe was used to detect cell mitochondrial membrane potential; 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) probe was used to detect intracellular reactive oxygen species; Annexin V-FITC/PI (fluorescein isothiocyanate/propidium) counterstaining method was used to detect apoptosis; Western blot assay was used to detect the expression level of related proteins. The experimental results show that SYT-1 has a significant inhibitory effect on the proliferation of six human-derived cancer cells. Among them, the inhibitory effect on breast cancer MCF-7 cells is the strongest, the half maximal inhibitory concentration (IC50) of SYT-1 of 48 h administration on MCF-7 cells is 5.87 μmol·L-1, which is better than that of cisplatin (8.92 μmol·L-1). Further studies have shown that SYT-1 can dose-dependently inhibit the monoclonal formation ability of MCF-7 cells, and can cause the mitochondrial membrane potential of the cells to decrease and the level of reactive oxygen species to increase. In addition, SYT-1 can significantly inhibit the activation of PI3K-Akt (phosphatidylinositol 3-kinase/protein kinase B) signaling pathway and induce apoptosis of MCF-7 cells. The above research results show that, as a new type of tetrahydroisoquinoline compound, SYT-1 has the potential to inhibit tumor cell proliferation.

Thioredoxin-Interacting Protein (TXNIP) Regulates Parkin/PINK1-mediated Mitophagy in Dopaminergic Neurons Under High-glucose Conditions: Implications for Molecular Links Between Parkinson's Disease and Diabetes.

Patients with diabetes mellitus have a higher risk of developing Parkinson's disease (PD). However, the molecular links between PD and diabetes remain unclear. In this study, we investigated the roles of thioredoxin-interacting protein (TXNIP) in Parkin/PINK1-mediated mitophagy in dopaminergic (DA) cells under high-glucose (HG) conditions. In streptozotocin-induced diabetic mice, TXNIP was upregulated and autophagy was inhibited in the midbrain, while the loss of DA neurons was accelerated by hyperglycemia. In cultured PC12 cells under HG, TXNIP expression was upregulated and the intracellular reactive oxygen species (ROS) levels increased, leading to cell death. Autophagic flux was further blocked and PINK1 expression was decreased under HG conditions. Parkin expression in the mitochondrial fraction and carbonyl cyanide 3-chlorophenylhydrazone (CCCP)-induced co-localization of COX IV (marker for mitochondria) and LAMP1 (marker for lysosomes) were also significantly decreased by HG. Overexpression of TXNIP was sufficient to decrease the expression of both PINK1 and Parkin in PC12 cells, while knockdown of the expression of TXNIP by siRNA decreased intracellular ROS and attenuated cellular injury under HG. Moreover, inhibition of TXNIP improved the CCCP-induced co-localization of COX IV and LAMP1 in PC12 cells under HG. Together, these results suggest that TXNIP regulates Parkin/PINK1-mediated mitophagy under HG conditions, and targeting TXNIP may be a promising therapeutic strategy for reducing the risk of PD under hyperglycemic conditions.

Case of Childhood Absence Epilepsy with Focal Spikes.

BACKGROUND: Childhood absence epilepsy is a common generalized epilepsy syndrome characterized by childhood onset of frequent sporadic absence seizures. During onset, the electroencephalogram exhibits bilateral, symmetric, and synchronous discharges of approximately 3 Hz of generalized spike-and-wave complexes. Focal spikes are often found in children with focal epilepsy but are not common in absence epilepsy. CASE DESCRIPTION: In the case patient, focal spikes were observed during active onset of absence epilepsy and at 5 years after the first hospital visit, at which time absence epilepsy was controlled and medication was withdrawn without focal seizure attack in the interim. CONCLUSIONS: This case demonstrates that focal spikes associated with childhood absence epilepsy do not require specific treatment in the absence of focal seizures.

Influence of BMP4 on Regulation of Cell Cycle and Apoptosis of Hematopoietic Stem Cells/Progenitor Cells and Its Mechanism in Chemotherapy-Induced Myelosuppression / 中国实验血液学杂志

OBJECTIVE@#To explore the effect of bone morphogenetic protein 4(BMP4) on the cell cycle and apoptosis of hemaropoictic stem and progenitor cells (HSPC) in conditions of 5-fluorouracil (5-FU)-inducing bone marrow suppression and stress hemogenesis, and its possible mechanism.@*METHODS@#The C57BL transgenic mice with BMP4 overexpression were established and were enrolled in transgenic group (BMP4 group), at the same time the wild type mice matching in age, sex and body weight were selected and were enrolled in control group (WT group). The bone marrow suppression was induced by injection with 5-FU in dose of 150 mg/kg, then the nucleated cells were isolated from bone marrow. After the HSPCs were markered with C-kit/sca-1 fluorescent antibodies, the changes of cell cycle and apoptosis of HSPC were detected by Aunexin V/PI and Ki67/DAPI double staining; the cell cycle-essociated hemotopoietic regulatory factors were detected by RT-qPCR.@*RESULTS@#Under physiologic status, there were no significant differences in cell cycle and apoptotic rate of HSPC between WT group and BMP-4 group. After the bone marrow was suppressed, the ratio of HSPC at G0 phase in BMP4 group significantly decreased(P＜0.05); the apoptosis rate of HSPC significantly increased(P＜0.05); the mRNA expression levels of hypoxia-inducing factor Hif-1α and chemotactic factor CXCL12 in stroma of BMP4 group were down-regulated significanfly(P＜0.05).@*CONCLUSION@#Under non-physiologic conditions such as stress hemogenesis or bone marrow suppression, the up-regulation of BMP4 can promote HSPC into cell cycle and apoptosis of HSPC, moreover, the BMP4 may play a regulatory role for cell cycle of HSPC through direct or indirect down-regulation of Hif-1α and CXCL-12 expressions.

Analysis of heart rate variability-related indexes in the interictal period in patients with focal epilepsy.

AIMS: Changes in cardiac autonomic nervous function have been evaluated by studying the related indexes of heart rate variability (HRV) in patients with focal epilepsy (FE) in the interictal period. MAIN METHODS: A total of 30 FE patients who were treated in our department from July 2015 to May 2017, were included into this study. These patients were divided into three pairs of groups: less frequent seizure group and more frequent seizure group; medication group and non-medication group; <10 years disease group and ≥10 years disease group. In addition, 16 normal healthy subjects were enrolled as the control group. The time domain and frequency domain indexes of HRV indexes between subgroups and the control group were retrospectively analyzed. KEY FINDINGS: The low-frequency/high-frequency ratio (LF/HF) in the interictal period was higher in the more frequent seizure group than in the control group and less frequent seizure group (P < 0.05). Furthermore, differences in interictal LF/HF and very low frequency (VLF) between the medication group and non-medication group and control group were statistically significant (P < 0.05). SIGNIFICANCE: In interictal period FE patients who present with an imbalance in autonomic nervous function, LF/HF can serve as an indicator to evaluate the interictal cardiac sympathetic activity of FE patients. Furthermore, the dynamic observation of changes in the HRV-related indexes of FE patients can prevent the choice of antiepileptic drugs that affect heart function, which is of guiding significance for evaluating autonomic nervous function.

Thioredoxin-interacting protein induced α-synuclein accumulation via inhibition of autophagic flux: Implications for Parkinson's disease.

AIMS: Thioredoxin-interacting protein (TXNIP) is associated with activation of oxidative stress through inhibition of thioredoxin (Trx). However, some evidences point out that TXNIP acts as a scaffolding protein in signaling complex independent of cellular redox regulation. The autophagy-lysosomal pathway plays important roles in the clearance of misfolded proteins and dysfunctional organelles. Lysosomal dysfunction has been involved in several neurodegenerative disorders including Parkinson's disease (PD). Although researchers have reported that TXNIP inhibited autophagic flux, the specific mechanism is rarely studied. METHODS: In this study, we investigated the effects of TXNIP on autophagic flux and α-synuclein accumulation by Western blot in HEK293 cells transfected with TXNIP plasmid. Further, we explored the influence of TXNIP on DA neuron survival in substantia nigra by IHC. RESULTS: We found that TXNIP induced LC3-II expression, but failed to degrade p62, a substrate of autophagy. Also, TXNIP aggravated α-synuclein accumulation. We also found that TXNIP inhibited the expression of ATP13A2, a lysosomal membrane protein. Moreover, we found that overexpression of ATP13A2 attenuated the impairment of autophagic flux and α-synuclein accumulation induced by TXNIP. Furthermore, overexpression of TXNIP in substantia nigra resulted in loss of DA neuron. CONCLUSION: Our data suggested that TXNIP blocked autophagic flux and induced α-synuclein accumulation through inhibition of ATP13A2, indicating TXNIP was a disease-causing protein in PD.

Increased glucagon-like peptide-1 secretion may be involved in antidiabetic effects of ginsenosides.

Panax ginseng is one of the most popular herbal remedies. Ginsenosides, major bioactive constituents in P. ginseng, have shown good antidiabetic action, but the precise mechanism was not fully understood. Glucagon-like peptide-1 (GLP1) is considered to be an important incretin that can regulate glucose homeostasis in the gastrointestinal tract after meals. The aim of this study was to investigate whether ginseng total saponins (GTS) exerts its antidiabetic effects via modulating GLP1 release. Ginsenoside Rb1 (Rb1), the most abundant constituent in GTS, was selected to further explore the underlying mechanisms in cultured NCI-H716 cells. Diabetic rats were developed by a combination of high-fat diet and low-dose streptozotocin injection. The diabetic rats orally received GTS (150 or 300 mg/kg) daily for 4 weeks. It was found that GTS treatment significantly ameliorated hyperglycemia and dyslipidemia, accompanied by a significant increase in glucose-induced GLP1 secretion and upregulation of proglucagon gene expression. Data from NCI-H716 cells showed that both GTS and Rb1 promoted GLP1 secretion. It was observed that Rb1 increased the ratio of intracellular ATP to ADP concentration and intracellular Ca2+ concentration. The metabolic inhibitor azide (3 mM), the KATP channel opener diazoxide (340 µM), and the Ca2+ channel blocker nifedipine (20 µM) significantly reversed Rb1-mediated GLP1 secretion. All these results drew a conclusion that ginsenosides stimulated GLP1 secretion both in vivo and in vitro. The antidiabetic effects of ginsenosides may be a result of enhanced GLP1 secretion.

Detecting human adenoviruses in respiratory samples collected from children with acute respiratory infections by loop-mediated isothermal amplification / 中华儿科杂志

<p><b>OBJECTIVE</b>To establish a rapid and reliable loop-mediated isothermal amplification (LAMP) method for detecting adenoviruses (ADV)in respiratory samples collected from children with acute respiratory infections.</p><p><b>METHOD</b>According to the sequences of hexon genes of common adenovirus serotypes (Ad3, Ad7, and Ad14) downloaded from GenBank, primers were designed and LAMP method for detecting adenovirus DNA was developed. Sensitivity of the LAMP method was evaluated by using constructed recombinant plasmid DNA with gene fragment from hexon of ADV3, and specificity was tested through cross-reaction with other viruses. Then 11 ADV strains isolated from clinical specimens using tissue cultures were tested by LAMP method. A total of 108 nasopharyngeal aspirates from hospitalized patients with acute respiratory infections which had been tested by direct immunofluorescence assay (DFA), including 36 for ADV positive and 72 for ADV negative, were tested by both LAMP method and multiplex nested PCR.</p><p><b>RESULT</b>Analysis for sensitivity indicated that this LAMP method can detect 1.9×10(2)copies/ml of DNA, and no amplification was shown in DNA or cDNA of other viruses, which revealed that the specificity of the LAMP method is high. For 108 specimens which had been tested by DFA, 34 out of the 36 ADV positive specimens showed positive signal within 90 minutes using LAMP. Five out of 72 negative specimens by DFA were positive using LAMP; 39 out of the 41 ADV positive specimens by multiplex nested PCR showed positive signal using LAMP, including 19 for Ad3 and 20 for Ad7; 67 negative specimens confirmed by multiplex nested PCR showed negative signal using LAMP. The total consistency rate of DFA and LAMP method for detecting ADV was 93.5%, and the total coincidence rate of multiplex nested PCR and LAMP method for detecting ADV was 98.1%.</p><p><b>CONCLUSION</b>A new, sensitive, accurate and rapid method for detecting human adenovirus from nasopharyngeal aspirates by LAMP was developed, which should be a potential method for rapid detection of ADV from respiratory tract of children in clinical diagnosis of ADV infection.</p>

Insulin deficiency induces abnormal increase in intestinal disaccharidase activities and expression under diabetic states, evidences from in vivo and in vitro study.

Structural and functional alterations in the gastrointestinal tract of diabetic patients are often accompanied by increase in absorption of intestinal glucose and activities of brush-border disaccharidases. The purpose of this study was to investigate the role of insulin in regulating intestinal disaccharidases using in vivo and in vitro experiments. Streptozotocin-induced diabetic rats and normal rats received protamine zinc insulin (10 IU/kg) subcutaneously twice daily for 5 weeks. Disaccharidase activities and sucrase-isomaltase (SI) complex protein and mRNA expression in intestinal regions were assessed. In addition, Caco-2 cells were cultured in medium containing glucose, insulin or insulin plus some pharmacological inhibitors for 7 days, disaccharidase activities, sucrase-isomaltase (SI) complex and Cdx2 mRNA levels were measured. The animal experiments showed that diabetes increased intestinal disaccharidase activities, accompanied by high mRNA and protein expression of SI complex. Insulin treatment reversed the increases induced by diabetes. The cellular results showed that insulin suppressed disaccharidase activities and down-regulated SI complex and Cdx2 mRNA expression in a concentration-dependent manner. The inhibitor of MAPK signal pathway PD-98059 blocked the suppression of disaccharidase activities and expression of SI complex and Cdx2 mRNA induced by insulin. In conclusion, insulin deficiency induces abnormal increase in intestinal disaccharidase activities and expression under diabetic states. Insulin plays an essential role in regulation disaccharidase activities and expression, at least in part, via the MAPK-dependent pathway.

Insulin suppresses the expression and function of breast cancer resistance protein in primary cultures of rat brain microvessel endothelial cells.

The aim of this study was to investigate the role of insulin in the regulation of breast cancer resistance protein (BCRP) function and expression using primary cultured rat brain microvessel endothelial cells (rBMECs) as an in vitro model of the blood brain barrier (BBB). The prazosin uptake assay and western blot analysis were used to assess the function and expression of BCRP, respectively. It was noted that the uptake of prazosin by rBMECs was time-, concentration- and temperature-dependent. The BCRP inhibitors novobiocin and imatinib mesylate significantly increased the uptake of prazosin by the cells in a concentration-dependent manner. The cells were also incubated with sera from diabetic rats for 72 h, serving as a diabetic in vitro model. We found that the uptake of prazosin by rBMECs incubated in the diabetic rat sera was 39.8% of that in normal rat sera, and insulin treatment reversed this decrease. Further results showed that insulin down-regulated the function and expression of BCRP in rBMECs in a concentration-dependent manner. Treatment with an antibody against the insulin receptor abolished the down-regulation of BCRP function and expression that was induced by insulin. These results indicate that insulin suppressed the function and expression of BCRPs in rBMEC primary cultures.

Verapamil exerts biphasic modulation on phenobarbital transport across the blood-brain barrier: evidence from an in vivo and in vitro study.

The aim of the study was to report a concentration-dependently biphasic effect of verapamil (VER) on the transport of phenobarbital (PB) across the blood-brain barrier (BBB) in vitro and in vivo. The uptake of PB by rat brain microvessel endothelial cells (rBMECs) and transport of PB across the rBMEC monolayer from apical to basolateral and basolateral to apical were evaluated in the presence of VER. The effect of VER on PB pharmacological activity on the central nervous system (CNS) and brain distribution of PB in mice were further investigated. The results showed that VER regulated the uptake of PB by rBMECs in a concentration-dependently biphasic manner. The uptake of PB by rBMECs was decreased by low concentrations of VER (1-25 µΜ), but increased by high concentrations of VER (50-300 µM). The biphasic regulation was also observed in transport experiment. In vivo studies showed that VER altered the pharmacological effect of PB on CNS and brain concentration of PB in a biphasic manner. In contrast to low doses of VER (0.125-0.5 mg/kg) that shortened the duration time of PB-induced loss of the righting reflex, high doses of VER (2-4 mg/kg) prolonged the duration time. Further study demonstrated that brain concentration of PB was decreased by 0.125 mg/kg VER, but increased by 2 mg/kg VER. The concentration-dependently biphasic regulation was also confirmed in the uptake of rhodamine 123 by rBMECs. Our results suggested that VER may regulate the transport of PB across BBB in a concentration-dependently biphasic manner and the biphasic regulation may be involved in P-gp function.

Sequence and antigenicity analysis for VP4s of EV71 strains isolated from Children in Beijing / 病毒学报

In order to learn about the correlation between the sequences of VP4 of EV71 and clinical symptoms of patients and analyze the antigenicity of VP4 of EV71, as well as the cross-reactivity with VP4 of CA16, the sequences of VP4 gene from 10 EV71 strains isolated from infants and children with hand, foot and mouth diseases (HFMD) during 2007 to 2009 were determined through standard molecular cloning protocols, and the results were analyzed by EditSeq and MegAlign of DNAStar. Full-length genes of VP4s of EV71 and CA16 were amplified from virus isolates and expressed in E. coli. Then the expressed VP4s were used as antigens to detect IgG antibody in 189 sera samples from people taking health check up and patients of non-HFMD by Western-Blot. They were also used to detect IgM antibody in 14 of sera samples from infants and children with EV71 infection and 12 of sera samples from those with CA16 infection. The nucleotides identities among these 10 sequences of VP4s isolated in our lab were 94.20% - 100.00% and the deduced amino acids were identical. There was no consistent divergence between the sequences of serious cases and those from general HFMD cases. Phylogenetic analysis based on VP4s indicated that these 10 VP4s of EV71 belonged to C4. The nucleotide identities between EV71 VP4 (s67) and CA16 VP4 (s401) was 69.60% and the deduced amino acids identities was 78.60%. In the detection of IgG, the sera-positive rate for EV71 VP4 was 38.10% and the sera-positive rate of CA16 VP4 was 58.20%. The difference in the sera-positive rate between them was significant (chi2 = 15.30, P < 0.01), suggesting that the expressed VP4s of EV71 and CA16 were of good antigenicity and not cross-reactive. There was no positive reaction detected for IgM against VP4s for EV71 or CA16. The data from this study reveal important information for the further study of EV71.

Berberine suppresses intestinal disaccharidases with beneficial metabolic effects in diabetic states, evidences from in vivo and in vitro study.

Clinical reports have demonstrated that berberine is a potential antidiabetic agent, but the underlying mechanism is unclear. The purpose of this study was to investigate if berberine exerts its hypoglycemic action via inhibiting intestinal disaccharidases using in vivo and in vitro experiments. Streptozotocin-induced diabetic rats received berberine (100 or 200 mg/kg) orally once daily or acarbose (40 mg/kg) orally twice daily for 5 weeks. Disaccharidase activities and sucrase-isomaltase (SI) complex messenger RNA (mRNA) expression in intestinal regions were assessed. The same treatment was operated in normal rats. Sucrose and maltose loading tests were also documented. In addition, Caco-2 cells were cultured in medium containing berberine or berberine plus chelerythrine. Compound C or H-89 for 5 days, disaccharidase activities, and SI complex mRNA levels were measured. The animal experiments showed that berberine significantly decreased the disaccharidase activities and SI complex mRNA expression both in diabetic rats and normal rats. Berberine can also significantly lower postprandial blood glucose levels induced by sucrose or maltose loading in normal rats. The cellular results showed that berberine may suppress disaccharidase activities and downregulate SI complex mRNA expression in a concentration-dependent manner. Only H-89, an inhibitor of protein kinase A (PKA), may reverse the decrease in disaccharidase activities and SI complex mRNA expression induced by berberine. In conclusion, berberine suppresses disaccharidase activities and SI complex mRNA expression with beneficial metabolic effects in diabetic states. The inhibitory effect, at least partly, involves the PKA-dependent pathway.

Huang-lian-jie-du-decoction modulates glucagon-like peptide-1 secretion in diabetic rats.

AIM OF THE STUDY: Huang-lian-jie-du-decoction (HLJDD), a well-known Chinese herbal formula, has been used for diabetic treatment. The purpose of the study was to investigate whether HLJDD affected glucagon-like peptide (GLP)-1 (7-36) amide level in diabetic rats. MATERIALS AND METHODS: Streptozotocin (STZ)-induced diabetic rats were treated with HLJDD at low dose (2 g/kg/day) or high dose (4 g/kg/day). After 5-week treatment, GLP-1 (7-36) amide level and insulin level in portal vein and tissues stimulated by oral glucose load were measured by ELISA kits. The proglucagon gene expression in intestinal tracts and the proliferation of intestinal L cell and pancreatic beta cell were measured using RT-PCR and immunohistochemistry techniques, respectively. RESULTS: It was found that 5-week HLJDD treatment attenuated alteration of glucose level and insulin level in plasma and tissues of diabetic rats induced by STZ, accompanied by improvement of diabetic syndrome. 5-week HLJDD treatment increased GLP-1 (7-36) amide level in portal vein plasma and distal ileum. Further studies showed that 5-week HLJDD treatment increased the mRNA level of proglucagon gene in distal ileum, promoted pancreatic beta cell and intestinal L cell proliferation in a dose-dependent manner. CONCLUSION: All the results indicated that HLJDD exerted its anti-diabetic effects partly via modulating GLP-1 (7-36) amide level.

Berberine promotes glucagon-like peptide-1 (7-36) amide secretion in streptozotocin-induced diabetic rats.

Berberine (BBR), a hypoglycemic agent, has shown beneficial metabolic effects for anti-diabetes, but its precise mechanism was unclear. Glucagon-like peptide-1 (GLP-1) is considered to be an important incretin that can decrease hyperglycemia in the gastrointestinal tract after meals. The aim of this study was to investigate whether BBR exerts its anti-diabetic effects via modulating GCG secretion. Diabetes-like rats induced by streptozotocin received BBR (120 mg/kg per day, i.g) for 5 weeks. Two hours following the last dose, the rats were anaesthetized and received 2.5 g/kg glucose by gavage. At 15-minute and 30-minute after glucose load, blood samples, pancreas, and intestines were obtained to measure insulin and GCG using ELISA kit. The number of L cells in the ileum and beta-cells in the pancreas were identified using immunohistology. The expression of proglucagon mRNA in the ileum was measured by RT-PCR. The results indicated that BBR treatment significantly increased GCG levels in plasma and intestine (P<0.05) accompanied with the increase of proglucagon mRNA expression and the number of L-cell compared with the controls (P<0.05). Furthermore, BBR increased insulin levels in plasma and pancreas as well as beta-cell number in pancreas. The data support the hypothesis that the anti-diabetic effects of BBR may partly result from enhancing GCG secretion.