- 1. PEG-chitosan-coated iron oxide nanoparticles with high saturated magnetization as carriers of 10-hydroxycamptothecin: preparation, characterization and cytotoxicity studies.
A magnetic nano-sized carrier for 10-hydroxycamptothecin (HCPT) was prepared by using Fe(3)O(4) nanoparticles as cores and chitosan (CS) as a polymeric shell by a novel reverse ultrasonic emulsification method. Poly(ethylene glycol) (PEG) chains were then coupled onto the magnetic particles (CS-Fe(3)O(4)) to improve their biocompatibility (PEG-CS-Fe(3)O(4)). HCPT was loaded onto PEG-CS-Fe(3)O(4) by a subtle precipitation method. Under optimum conditions, the CS-Fe(3)O(4) was close to spherical in shape with an average size of 174 nm and a high saturated magnetization. After coupling PEG chains, the unspecific adsorption of bovine serum albumin (BSA) on PEG-CS-Fe(3)O(4) decreased significantly. The drug loading content and loading efficiency were 9.8-11.8% and 49-59% for magnetic composite nanoparticles, respectively. HCPT-loaded magnetic composite nanoparticles showed sustained release profiles up to 48 h, and the cumulative release amount of HCPT from nanoparticles at 45°C increased significantly compared to that at 37°C. Cytotoxicity assay suggests that CS-Fe(3)O(4) does not exhibit noteworthy cytotoxicity against HepG2 cells, but the antitumor activities of HCPT-loaded magnetic composite nanoparticles against HepG2 cells increased significantly in comparison with that of pristine HCPT powder. These results reveal the promising potential of PEG-CS-Fe(3)O(4) as a stable magnetic targeting drug carrier in cancer therapy....(more)
Qu JB, et al. Colloids Surf B Biointerfaces 2013 Feb 1;102:37-44.
Related Products: 10-Hydroxycamptothecin
- 2. Synthesis, characterization, and antitumor evaluation of the albumin-SN38 conjugate.
7-Ethyl-10-hydroxycamptothecin (SN38), the active metabolite of irinotecan, exerts a 100-fold to 1000-fold higher effect than irinotecan itself against several tumor cell lines. However, the water insolubility of SN38 has prevented its direct use as an antitumor drug in the clinic. To improve the water solubility and antitumor efficacy, SN38 was covalently attached to the only free sulfhydryl at cysteine-34 on the BSA site specifically through a thiol-binding linker to form a prodrug BSA-SN38 conjugate (BSA : SN38=1 : 1). The water solubility of this conjugate was similar to albumin using the current method. Also, SN38 loading in this conjugate became controllable. Size-exclusion chromatography purification and UV characterization of the SDS-PAGE electrophoresis product were carried out. Then, an MTT assay was carried out to test the antitumor effect of this conjugate on five colon cancer cell lines in vitro. The 72 h IC50 values of the BSA-SN38 conjugate ranged from 1.5 to 6.1 μmol/l. A colorectal peritoneal carcinomatosis model in mice was established to determine the intraperitoneal chemotherapy effect of the BSA-SN38 conjugate. The BSA-SN38 conjugate at an SN38 equivalent dose of 10 mg/kg/day was administrated every 4 days. Eighteen days after manipulation, the mice were euthanized and the tumors in the abdominal cavity were collected and weighed. Tumors in the BSA-SN38 conjugate treatment group (m=0.21 ± 0.15 g) were found to be significantly (P=5) lighter than those in the NS control group (m=4.74±0.73 g). The results indicated that this water-soluble BSA-SN38 conjugate exerted a strong antitumor effect on colorectal carcinoma....(more)
Yao Y, et al. Anticancer Drugs 2013 Mar;24(3):270-7.
Related Products: 10-Hydroxycamptothecin
- 3. Effect of genistein, a natural soy isoflavone, on the pharmacokinetics and intestinal toxicity of irinotecan hydrochloride in rats.
OBJECTIVES:
The effect of genistein, a natural soy isoflavone, on pharmacokinetics and intestinal toxicity, or late-onset diarrhoea, of irinotecan hydrochloride (CPT-11) was examined in rats.
METHODS:
Probenecid, a typical inhibitor of multidrug resistance-associated protein (MRP) 2, was also employed for comparison with genistein. Plasma concentration, biliary excretion and intestinal secretion of CPT-11, 7-ethyl-10-hydroxycamptothecin (SN-38) and SN-38 glucuronide (SN-38G) were determined in untreated, genistein-treated and probenecid-treated rats. CPT-11 was administered repeatedly by intravenous injection (60 mg/kg/day for 4 days), and the effects of genistein and probenecid on CPT-11-induced intestinal toxicity were evaluated by measuring body weight, induction of diarrhoea, and alkaline phosphatase (ALP) activity in the intestinal mucosal membranes.
KEY FINDINGS:
Genistein, as well as probenecid, significantly suppressed the MRP2-mediated biliary and intestinal secretion of CPT-11 and its metabolites and increased their plasma concentrations. Multiple administration of CPT-11 reduced body weight and ALP activity, and induced watery diarrhoea. Genistein, as well as probenecid, significantly suppressed the loss in body weight and the reduced mucosal ALP activity in the ileum, and ameliorated the symptoms of diarrhoea induced by CPT-11.
CONCLUSIONS:
Intravenous genistein was effective in ameliorating CPT-11-induced late-onset diarrhoea, by suppressing MRP2-mediated biliary excretion of CPT-11 and its metabolites.
© 2012 The Authors. JPP © 2012. Royal Pharmaceutical Society....(more)
Yokooji T, et al. J Pharm Pharmacol 2013 Feb;65(2):280-91.
Related Products: 10-Hydroxycamptothecin
- 4. Bioluminescence imaging of DNA synthetic phase of cell cycle in living animals.
Bioluminescence reporter proteins have been widely used in the development of tools for monitoring biological events in living cells. Currently, some assays like flow cytometry analysis are available for studying DNA synthetic phase (S-phase) targeted anti-cancer drug activity in vitro; however, techniques for imaging of in vivo models remain limited. Cyclin A2 is known to promote S-phase entry in mammals. Its expression levels are low during G1-phase, but they increase at the onset of S-phase. Cyclin A2 is degraded during prometaphase by ubiquitin-dependent, proteasome-mediated proteolysis. In this study, we have developed a cyclin A2-luciferase (CYCA-Luc) fusion protein targeted for ubiquitin-proteasome dependent degradation, and have evaluated its utility in screening S-phase targeted anti-cancer drugs. Similar to endogenous cyclin A2, CYCA-Luc accumulates during S-phase and is degraded during G2/M-phase. Using Cdc20 siRNA we have demonstrated that Cdc20 can mediate CYCA-Luc degradation. Moreover, using noninvasive bioluminescent imaging, we demonstrated accumulation of CYCA-Luc in response to 10-hydroxycamptothecin (HCPT), an S-phase targeted anti-cancer drug, in human tumor cells in vivo and in vitro. Our results indicate that a CYCA-Luc fusion reporter system can be used to monitor S-phase of cell cycle, and evaluate pharmacological activity of anti-cancer drug HCPT in real time in vitro and in vivo, and is likely to provide an important tool for screening such drugs....(more)
Chen ZH, et al. PLoS One 2013;8(1):e53291.
Related Products: 10-Hydroxycamptothecin
- 5. Assessing the regioselectivity of OleD-catalyzed glycosylation with a diverse set of acceptors.
To explore the acceptor regioselectivity of OleD-catalyzed glucosylation, the products of OleD-catalyzed reactions with six structurally diverse acceptors flavones- (daidzein), isoflavones (flavopiridol), stilbenes (resveratrol), indole alkaloids (10-hydroxycamptothecin), and steroids (2-methoxyestradiol)-were determined. This study highlights the first synthesis of flavopiridol and 2-methoxyestradiol glucosides and confirms the ability of OleD to glucosylate both aromatic and aliphatic nucleophiles. In all cases, molecular dynamics simulations were consistent with the determined product distribution and suggest the potential to develop a virtual screening model to identify additional OleD substrates....(more)
Zhou M, et al. J Nat Prod 2013 Feb 22;76(2):279-86.
Related Products: 10-Hydroxycamptothecin
- 6. The relative protein abundance of UGT1A alternative splice variants as a key determinant of glucuronidation activity in vitro.
Alternative splicing (AS) is one of the most significant components of the functional complexity of human UDP-glucuronosyltransferase enzymes (UGTs), particularly for the UGT1A gene, which represents one of the best examples of a drug-metabolizing gene regulated by AS. Shorter UGT1A isoforms [isoform 2 (i2)] are deficient in glucuronic acid transferase activity but function as negative regulators of enzyme activity through protein-protein interaction. Their abundance, relative to active UGT1A enzymes, is expected to be a determinant of the global transferase activity of cells and tissues. Here we tested whether i2-mediated inhibition increases with greater abundance of the i2 protein relative to the isoform 1 (i1) enzyme, using the extrahepatic UGT1A7 as a model and a series of 23 human embryonic kidney 293 clonal cell lines expressing variable contents of i1 and i2 proteins. Upon normalization for i1, a significant reduction of 7-ethyl-10-hydroxycamptothecin glucuronide formation was observed for i1+i2 clones (mean of 53%) compared with the reference i1 cell line. In these clones, the i2 protein content varied greatly (38-263% relative to i1) and revealed two groups: 17 clones with i2 < i1 (60% ± 3%) and 6 clones with i2 ≥ i1 (153% ± 24%). The inhibition induced by i2 was more substantial for clones displaying i2 ≥ i1 (74.5%; P = 0.001) compared with those with i2 < i1 (45.5%). Coimmunoprecipitation supports a more substantial i1-i2 complex formation when i2 exceeds i1. We conclude that the relative abundance of regulatory i2 proteins has the potential to drastically alter the local drug metabolism in the cells, particularly when i2 surpasses the protein content of i1....(more)
Rouleau M, et al. Drug Metab Dispos 2013 Apr;41(4):694-7.
Related Products: 10-Hydroxycamptothecin
- 7. Activation of a PGC-1-related coactivator (PRC)-dependent inflammatory stress program linked to apoptosis and premature senescence.
PGC-1-related coactivator (PRC), a growth-regulated member of the PGC-1 coactivator family, contributes to the expression of the mitochondrial respiratory apparatus. PRC also orchestrates a robust response to metabolic stress by promoting the expression of multiple genes specifying inflammation, proliferation, and metabolic reprogramming. Here, we demonstrate that this PRC-dependent stress program is activated during apoptosis and senescence, two major protective mechanisms against cellular dysfunction. Both PRC and its targets (IL1α, SPRR2D, and SPRR2F) were rapidly induced by menadione, an agent that promotes apoptosis through the generation of intracellular oxidants. Menadione-induced apoptosis and the PRC stress program were blocked by the antioxidant N-acetylcysteine. The PRC stress response was also activated by the topoisomerase I inhibitor 7-ethyl-10-hydroxycamptothecin (SN-38), an inducer of premature senescence in tumor cells. Cells treated with SN-38 displayed morphological characteristics of senescence and express senescence-associated β-galactosidase activity. In contrast to menadione, the SN-38 induction of the PRC program occurred over an extended time course and was antioxidant-insensitive. The potential adaptive function of the PRC stress response was investigated by treating cells with meclizine, a drug that promotes glycolytic energy metabolism and has been linked to cardio- and neuroprotection against ischemia-reperfusion injury. Meclizine increased lactate production and was a potent inducer of the PRC stress program, suggesting that PRC may contribute to the protective effects of meclizine. Finally, c-MYC and PRC were coordinately induced under all conditions tested, implicating c-MYC in the biological response to metabolic stress. The results suggest a general role for PRC in the adaptive response to cellular dysfunction....(more)
Gleyzer N, et al. J Biol Chem 2013 Mar 22;288(12):8004-15.
Related Products: 10-Hydroxycamptothecin
- 8. Enhanced tumor targeting and antitumor efficacy via hydroxycamptothecin-encapsulated folate-modified N-succinyl-N'-octyl chitosan micelles.
10-Hydroxycamptothecin (HCPT) is an effective anticancer drug against various types of solid tumors. But the antitumor efficacy of HCPT is far from satisfactory because of its poor physicochemical properties, short circulating half-life, low stability, and nonspecific toxicity to normal tissues. Therefore, a targeted delivery strategy for HCPT to pathological sites is eagerly needed to overcome these limitations. The folate-modified N-succinyl-N'-octyl chitosan (folate-SOC) micelle was chosen in this study and served as the targeted delivery system for HCPT to improve the antitumor efficacy. The water-insoluble anticancer drug HCPT was encapsulated into the folate-SOC micelles by the dialysis method. The near-spherical HCPT-loaded folate-SOC (HCPT/folate-SOC) micelles were formed in aqueous media with diameter of about 100-200 nm. The HCPT/folate-SOC micelles displayed a good stability, reasonable drug-loading content (about 10%), and sustained release behavior for the water-insoluble HCPT. Compared with free HCPT, HCPT/folate-SOC micelles exhibited a significant enhancement of cellular uptake, higher cytotoxicity against folate receptor positive tumor cell (Bel-7402), excellent tumor-targeting capability and substantially better antitumor efficacy on the nude mice bearing Bel-7402 xenografts. These results demonstrate the potential of folate-SOC micelles as long-term stable and effective drug delivery systems in cancer therapy....(more)
Zhu H, et al. J Pharm Sci 2013 Apr;102(4):1318-32.
Related Products: 10-Hydroxycamptothecin
- 9. Co-delivery of 10-Hydroxycamptothecin with Doxorubicin Conjugated Prodrugs for Enhanced Anticancer Efficacy.
Well-defined amphiphilic linear-dendritic prodrugs (MPEG-b-PAMAM-DOX) are synthesized by conjugating doxorubicin (DOX), to MPEG-b-PAMAM through the acid-labile hydrazone bond. The amphiphilic prodrugs form self-assembled nanoparticles in deionized water and encapsulate the hydrophobic anticancer drug 10-hydroxycamptothecin (HCPT) with a high drug loading efficiency. Studies on drug release and cellular uptake of the co-delivery system reveal that both drugs are released in a pH-dependent manner and effectively taken up by MCF-7 cells. In vitro methyl thiazolyl tetrazolium (MTT) assays and drug-induced apoptosis tests demonstrate the HCPT-loaded nanoparticles suppress cancer cell growth more efficiently than the MPEG-b-PAMAM-DOX prodrugs, free HCPT, and physical mixtures of MPEG-b-PAMAM-DOX and HCPT at equivalent DOX or HCPT doses....(more)
Zhang Y, et al. Macromol Biosci 2013 Feb 18.
Related Products: 10-Hydroxycamptothecin
- 10. Comparison of the effects of mitomycin C and 10-hydroxycamptothecin on an experimental intraarticular adhesion model in rabbits.
The study was to compare the preventive effects of the local application of mitomycin C (MMC) and 10-hydroxycamptothecin (HCPT) on reducing intraarticular adhesion after knee surgery in rabbit model. Thirty-six New-Zealand rabbits were randomly and equally divided into three groups: MMC, HCPT and control group. Approximately 10mm×10mm of the cortical bone was removed from both sides of left femoral condyle and the cancellous bone underneath was exposed. The exposed decorticated areas were covered with cotton pads soaked with MMC (0.1mg/ml), HCPT (0.1mg/ml) and physiological saline for 10min. The left knee joint was then fixed in the fully flexed position with a Kirschner wire for 4 weeks after surgery. The rabbits were killed after 4 weeks and multiple parameters including the macroscopic evaluation, the hydroxyproline content, the histological evaluation and the fibroblast counts were used to evaluate the effect of MMC and HCPT on preventing intraarticular adhesion. The results showed that weak fibrous adhesions were found around the decorticated areas in MMC group and moderate intraarticular adhesions were found in HCPT group. However, there were severe fibrous adhesions around the decorticated areas in control group. The hydroxyproline contents and the fibroblast numbers of MMC and HCPT group were significantly less than those of control group. In conclusion, our data showed that topical application of MMC and HCPT could prevent intraarticular adhesion after knee surgery in rabbit model, but MMC had a better preventive effect than that of HCPT....(more)
Li X, et al. Eur J Pharmacol 2013 Mar 5;703(1-3):42-5.
Related Products: 10-Hydroxycamptothecin
- 11. Hypoxia modulates A431 cellular pathways association to tumor radioresistance and enhanced migration revealed by comprehensive proteomic and functional studies.
Tumor hypoxia induces cancer cell angiogenesis, invasiveness, treatment resistance, and contributes to poor clinical outcome. However, the molecular mechanism by which tumor hypoxia exerts a coordinated effect on different molecular pathways to enhance tumor growth and survival and lead to poor clinical outcome is not fully understood. In this study, we attempt to elucidate the global protein expression and functional changes in A431 epithelial carcinoma cells induced by hypoxia and reoxygenation using iTRAQ quantitative proteomics and biochemical functional assays. Quantitative proteomics results showed that 4316 proteins were quantified with FDR<1%, in which over 1200 proteins were modulated >1.2 fold, and DNA repair, glycolysis, integrin, glycoprotein turnover, and STAT1 pathways were perturbed by hypoxia and reoxygenation-induced oxidative stress. For the first time, hypoxia was shown to up-regulate the nonhomologous end-joining pathway, which plays a central role in DNA repair of irradiated cells, thereby potentially contributing to the radioresistance of hypoxic A431 cells. The up-regulation of Ku70/Ku80 dimer, a key molecular complex in the nonhomologous end-joining pathway, was confirmed by Western blot and liquid chromatography/tandem mass spectrometry-MRM methods. Functional studies confirmed that up-regulation of glycolysis, integrin, glycoprotein synthesis, and down-regulation of STAT1 pathways during hypoxia enhanced metastastic activity of A431 cells. Migration of A431 cells was dramatically repressed by glycolysis inhibitor (2-Deoxy-d-glucose), glycoprotein synthesis inhibitor (1-Deoxynojirimycin Hydrochloride), and STAT1α overexpression that enhanced the integrin-mediated cell adhesion. These results revealed that hypoxia induced several biological processes involved in tumor migration and radioresistance and provided potential new targets for tumor therapy....(more)
Ren Y, et al. Mol Cell Proteomics 2013 Feb;12(2):485-98.
Related Products: 1-Deoxynojirimycin
- 12. Production of the α-glycosidase inhibitor 1-deoxynojirimycin from Bacillus species.
1-Deoxynojirimycin (DNJ), a potent α-glycosidase inhibitor, has therapeutic applications in treatments of HIV, Gaucher's disease, and diabetes. DNJ has been extracted from natural sources (mulberry leaves) for therapeutic purposes; however, DNJ ingredients are in limited supply and are costly to obtain on a large scale. Since certain strains of Bacillus and Streptomyces species reportedly produce DNJ, they may serve as potential sources for high-yield DNJ production. In this study, we obtained evidence for a DNJ production in Bacillus subtilis DSM704 by hydrophilic interaction chromatography-tandem mass spectrometry. In addition, from a screen of 750 microorganisms, we identified additional Bacillus strains (Bacillus amyloliquefaciens AS385 and Bacillus subtilis B4) that produce DNJ in large quantities. Investigation of the effect of various culture conditions, using Bacillus subtilis DSM704 and the DNJ high-production Bacillus strains, provided evidence for the importance of sorbitol supplementation on the yield of the DNJ precursor, 2-amino-2-deoxy-D-mannitol, thereby increasing DNJ production. The role of sorbitol in increased DNJ production was supported by an observed increase in mRNA expression of the biosynthetic gene, gabT1. When Bacillus amyloliquefaciens AS385 was cultured in medium supplemented with sorbitol, extracellular DNJ concentration reached a maximum of 460 mg/l of medium (equivalent to 9.20mg/g of freeze-dried medium), indicating that this strain can serve as a source for food- and drug-grade products. These findings not only lead to a further understanding of the DNJ biosynthetic pathway, but also suggest a method for microbial mass production of DNJ for therapeutic applications....(more)
Onose S, et al. Food Chem 2013 May 1;138(1):516-23.
Related Products: 1-Deoxynojirimycin
- 13. Isolation of the putative biosynthetic gene cluster of 1-deoxynojirimycin by Bacillus amyloliquefaciens 140N, its production and application to the fermentation of soybean paste.
The 1-deoxynojirimycin (DNJ) biosynthetic gene cluster of Bacillus amyloliquefaciens 140N isolated from traditional Korean fermented food was isolated by PCR screening. It showed 78.9% inhibitory activity against α-glucosidase and produced 0.8 g/L of DNJ in an optimized medium containing 2% soluble starch, 1% tryptone, 0.05% KH(2)PO(4), and 0.05% (NH(2))(4)SO(4). Soybean paste fermented with B. amyloliquefaciens 140N produced DNJ with 84.4% inhibitory activity....(more)
Seo MJ, et al. Biosci Biotechnol Biochem 2013;77(2):398-401.
Related Products: 1-Deoxynojirimycin
- 14. 1-deoxynojirimycin inhibits glucose absorption and accelerates glucose metabolism in streptozotocin-induced diabetic mice.
We investigated the role of 1-deoxynojirimycin (DNJ) on glucose absorption and metabolism in normal and diabetic mice. Oral and intravenous glucose tolerance tests and labeled (13)C6-glucose uptake assays suggested that DNJ inhibited intestinal glucose absorption in intestine. We also showed that DNJ down-regulated intestinal SGLT1, Na(+)/K(+)-ATP and GLUT2 mRNA and protein expression. Pretreatment with DNJ (50mg/kg) increased the activity, mRNA and protein levels of hepatic glycolysis enzymes (GK, PFK, PK, PDE1) and decreased the expression of gluconeogenesis enzymes (PEPCK, G-6-Pase). Assays of protein expression in hepatic cells and in vitro tests with purified enzymes indicated that the increased activity of glucose glycolysis enzymes was resulted from the relative increase in protein expression, rather than from direct enzyme activation. These results suggest that DNJ inhibits intestinal glucose absorption and accelerates hepatic glucose metabolism by directly regulating the expression of proteins involved in glucose transport systems, glycolysis and gluconeogenesis enzymes....(more)
Li YG, et al. Sci Rep 2013 Mar 28;3:1377.
Related Products: 1-Deoxynojirimycin
- 15. Kinetic and thermodynamic analysis of the inhibitory effects of maltose, glucose, and related carbohydrates on wheat β-amylase.
Inhibition of wheat β-amylase (WBA) by glucose and maltose was studied by kinetics and thermodynamics. The inhibitory effects of fructose, difructose, sucrose, trehalose, cellobiose, acarbose, and 1-deoxynojirimycin on WBA were also evaluated. The half maximal inhibitory concentrations (IC50) of acarbose, maltose and glucose were 0.06±0.01M, 0.22±0.09M, and 1.41±0.17M, respectively. The inhibitor constant (Ki) and the thermodynamic parameters such as changes in Gibbs energy (ΔG), enthalpy (ΔH), and entropy (ΔS) of the dissociation reactions of the WBA-glucose and WBA-maltose complexes were temperature and pH-dependent. The dissociation reactions were endothermic and enthalpy-driven. Both glucose and maltose behaved as competitive inhibitors at pH 3.0 and 5.4 at a temperature of 25°C with respective Ki values of 0.33±0.02M and 0.12±0.03M. In contrast, both sugars exhibited uncompetitive inhibition at pH 9 at a temperature of 25°C with Ki values of 0.21±0.03M for glucose and 0.11±0.04M for maltose. The pH-dependence of the inhibition type and Ki values indicate that the ionizing groups of WBA influence drastically the interaction with these carbohydrates. This evidence enables us to consider temperature and pH in the WBA-catalyzed hydrolysis to manipulate the inhibition by end-product, maltose, and even by glucose....(more)
Daba T, et al. Enzyme Microb Technol 2013 Apr 10;52(4-5):251-7.
Related Products: 1-Deoxynojirimycin
- 16. Intake of mulberry 1-deoxynojirimycin prevents diet-induced obesity through increases in adiponectin in mice.
In this study, the anti-obesity effect of 1-deoxynojirimycin (DNJ) was examined in the diet-induced obese mouse model. Mulberry DNJ was administered to the obese mice for 12weeks. As a result, DNJ decreased both the visceral fat weight and adipocyte size. To determine the influence of DNJ on lipid metabolism, lipid parameters of the plasma and the liver and the activities of several molecules related to lipid metabolism in the liver were measured. DNJ activated the β-oxidation system, suppressed lipid accumulation in the liver and reduced plasma triacylglycerol. Since it was thought that the factor activated in the β-oxidation system was adiponectin, plasma adiponectin levels were measured and it was shown that plasma adiponectin was increased with DNJ. Therefore, it was suggested that DNJ promoted an increase in plasma adiponectin and activated the β-oxidation system. Overall, it was shown that DNJ prevents diet-induced obesity through an increase in adiponectin....(more)
Tsuduki T, et al. Food Chem 2013 Aug 15;139(1-4):16-23.
Related Products: 1-Deoxynojirimycin
- 17. A Fully Unsupervised Compartment-on-Demand Platform for Precise Nanoliter Assays of Time-Dependent Steady-State Enzyme Kinetics and Inhibition.
The ability to miniaturize biochemical assays in water-in-oil emulsion droplets allows a massive scale-down of reaction volumes, so that high-throughput experimentation can be performed more economically and more efficiently. Generating such droplets in compartment-on-demand (COD) platforms is the basis for rapid, automated screening of chemical and biological libraries with minimal volume consumption. Herein, we describe the implementation of such a COD platform to perform high precision nanoliter assays. The coupling of a COD platform to a droplet absorbance detection set-up results in a fully automated analytical system. Michaelis-Menten parameters of 4-nitrophenyl glucopyranoside hydrolysis by sweet almond β-glucosidase can be generated based on 24 time-courses taken at different substrate concentrations with a total volume consumption of only 1.4 μL. Importantly, kinetic parameters can be derived in a fully unsupervised manner within 20 min: droplet production (5 min), initial reading of the droplet sequence (5 min), and droplet fusion to initiate the reaction and read-out over time (10 min). Similarly, the inhibition of the enzymatic reaction by conduritol B epoxide and 1-deoxynojirimycin was measured, and Ki values were determined. In both cases, the kinetic parameters obtained in droplets were identical within error to values obtained in titer plates, despite a >10<sup>4</sup>-fold volume reduction, from micro- to nanoliters....(more)
Gielen F, et al. Anal Chem 2013 Apr 24.
Related Products: 1-Deoxynojirimycin
- 18. 1-Deoxynojirimycin Isolated from a Bacillus subtilis Stimulates Adiponectin and GLUT4 Expressions in 3T3-L1 Adipocytes.
We have demonstrated that 1-deoxynojirimycin (DNJ) isolated from Bacillus subtilis MORI could enhance the levels of adiponectin and its receptors in differentiated 3T3-L1 adipocytes, which has been shown to be effective in lowering blood glucose levels and enhancing insulin sensitivity. DNJ was not toxic to differentiated 3T3-L1 adipocytes for up to a concentration of 5 microM. In terms of expression levels of adiponectin and its receptors (AdipoR1 and AdipoR2), DNJ in concentrations as low as 0.5 microM elevated both mRNA and protein levels of adiponectin and transcript levels of AdipoR1 and AdipoR2. In addition, DNJ increased phosphorylation of 5' adenosine monophosphateactivated protein kinase (AMPK) in a statistically significant manner. Finally, treatment with DNJ resulted in increased mRNA expression of glucose transporter 4 (GLUT4), which encodes for a glucose transporter, along with a significant increase in glucose uptake into the adipocytes based on results of a 2-deoxy-D-[3H] glucose uptake assay. Our findings indicate that DNJ may greatly facilitate glucose uptake into adipose tissues by increasing the action of adiponectin via its up-regulated expression as well as its receptor genes. In addition, the glucose-lowering effects of DNJ may be achieved by an increased abundance of GLUT4 protein in the plasma membrane, as a consequence of the increased transcript levels of the GLUT4 gene and the activation of AMPK....(more)
Lee SM, et al. J Microbiol Biotechnol 2013 May;23(5):637-43.
Related Products: 1-Deoxynojirimycin
- 19. Studies Targeting α-Glucosidase Inhibition, Antiangiogenic Effects, and Lipid Modification Regulation: Background, Evaluation, and Challenges in the Development of Food Ingredients for Therapeutic Purposes.
Since the discovery of α-glucosidase inhibitors and their inhibitory effects on the digestion of carbohydrates, promising results have been obtained as to the antidiabetic effects of this family of compounds. Antiangiogenic compounds have been identified that suppress tumor growth via a unique mechanism, confirming that such compounds can act as clinically applicable anticancer agents. Lipid peroxidation and lipid glycation have been suggested to play roles in food deterioration and in the pathophysiology of human diseases such as atherogenesis and diabetes, and antioxidative and antiglycative compounds can potentially be used in the prevention of food deterioration as well as to treat disease. On this basis, this review describes studies of α-glucosidase inhibition by mulberry 1-deoxynojirimycin, antiangiogenic effects of rice bran tocotrienol, and membrane lipid peroxidation/glycation and its inhibitors. These studies are ongoing in our work, with an emphasis on analytical techniques....(more)
Nakagawa K. Biosci Biotechnol Biochem 2013 May 7.
Related Products: 1-Deoxynojirimycin
- 20. An iminosugar N-pentafluorobenzyl-1-deoxynojirimycin as a novel potential immunosuppressant for the treatment of Th2-related diseases.
Increased levels of Th2 cytokine interleukin-4 (IL-4) have been reported to be involved in the pathogenesis of the parasite Schistosoma japonicum (S. japonicum) infection or detected in the serum of the causative agent of acquired immunodeficiency syndrome (AIDS) patients. This correlates with a worsened outcome of AIDS. The inhibition of a Th2 type response might aid in the treatment of these Th2-related diseases. Previously, we found that N-pentafluorobenzyl-1-deoxynojirimycin (5F-DNM), a new derivative of 1-deoxynojirimycin (DNM) (an inhibitor of the glycoprotein processing enzymes, glucosidase I and II), had specific inhibition effects on human CD4(+) T cells. In this study, we further found that 5F-DNM not only markedly inhibited in vitro IL-4 production from human PBMCs, CD4(+) T cells and mouse splenocytes but also strongly inhibited the production of IL-4 in splenocytes from a mouse model of S. japonicum infection. The numbers of S. japonicum worms were significantly decreased in vivo upon the treatment of mice with 5F-DNM. We demonstrated the mechanism of 5F-DNM effects on CD4(+) T cells acts via the inhibition of the IL-4/JAK1/STAT6 signaling pathway. Moreover, 5F-DNM was found to induce CD4 internalization (transfer from the cellular surface to the cytoplasm) in CD4(+) T cells and had no significant effects on the overall expression levels of CD4. These findings indicate that 5F-DNM might be used as a potential candidate for the treatment of S. japonicum parasitic infection, AIDS and other Th2-related diseases....(more)
Liu M, et al. Bioorg Med Chem Lett 2012 Jan 1;22(1):564-70.
Related Products: 1-Deoxynojirimycin
- 21. A novel l-isoleucine-4'-dioxygenase and l-isoleucine dihydroxylation cascade in Pantoea ananatis.
A unique operon structure has been identified in the genomes of several plant- and insect-associated bacteria. The distinguishing feature of this operon is the presence of tandem hilA and hilB genes encoding dioxygenases belonging to the PF13640 and PF10014 (BsmA) Pfam families, respectively. The genes encoding HilA and HilB from Pantoea ananatis AJ13355 were cloned and expressed in Escherichia coli. The culturing of E. coli cells expressing hilA (E. coli-HilA) or both hilA and hilB (E. coli-HilAB) in the presence of l-isoleucine resulted in the conversion of l-isoleucine into two novel biogenic compounds: l-4'-isoleucine and l-4,4'-dihydroxyisoleucine, respectively. In parallel, two novel enzymatic activities were detected in the crude cell lysates of the E. coli-HilA and E. coli-HilAB strains: l-isoleucine, 2-oxoglutarate: oxygen oxidoreductase (4'-hydroxylating) (HilA) and l-4'-hydroxyisoleucine, 2-oxoglutarate: oxygen oxidoreductase (4-hydroxylating) (HilB), respectively. Two hypotheses regarding the physiological significance of C-4(4')-hydroxylation of l-isoleucine in bacteria are also discussed. According to first hypothesis, the l-isoleucine dihydroxylation cascade is involved in synthesis of dipeptide antibiotic in P. ananatis. Another unifying hypothesis is that the C-4(4')-hydroxylation of l-isoleucine in bacteria could result in the synthesis of signal molecules belonging to two classes: 2(5H)-furanones and analogs of N-acyl homoserine lactone....(more)
Smirnov SV, et al. Microbiologyopen 2013 Apr 2.
Related Products: 4-Hydroxyisoleucine
- 22. Non-insulin dependent anti-diabetic activity of (2S, 3R, 4S) 4-hydroxyisoleucine of fenugreek (Trigonella foenum graecum) in streptozotocin-induced type I diabetic rats.
The seeds of fenugreek, Trigonella foenum graecum, commonly used as a spice in Middle Eastern countries and widely used in south Asia and Europe, are known to have anti-diabetic properties. They contain an unusual amino acid (2S, 3R, 4S) 4-hydroxyisoleucine (4HO-Ile), so far found only in fenugreek, which has anti-diabetic properties of enhancing insulin secretion under hyperglycaemic conditions, and increasing insulin sensitivity. Here we describe for the first time the anti-diabetic activity of 4HO-Ile in a model of type I diabetes, streptozotocin-treated rats, where levels of insulin are much reduced, by 65%, compared to normal animals. Treatment of diabetic rats with daily doses of 4HO-Ile at 50 mg/kg/day for four weeks could reduce plasma glucose in the diabetic group. Moreover the high levels of lipids (cholesterol, HDL, LDL and triglycerides) and uric acid in the diabetic rats, could be restored to levels found in non-diabetic controls by the treatment with 4HO-Ile. These results demonstrate that 4HO-Ile has significant anti-diabetic activities that are independent of insulin and suggest the potential of 4HO-Ile as an adjunct to diabetes treatment and for type 1 as well as type 2 diabetes....(more)
Haeri MR, et al. Phytomedicine 2012 May 15;19(7):571-4.
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- 23. A novel family of bacterial dioxygenases that catalyse the hydroxylation of free L-amino acids.
L-isoleucine-4-hydroxylase (IDO) is a recently discovered member of the Pfam family PF10014 (the former DUF 2257 family) of uncharacterized conserved bacterial proteins. To uncover the range of biochemical activities carried out by PF10014 members, eight in silico-selected IDO homologues belonging to the PF10014 were cloned and expressed in Escherichia coli. L-methionine, L-leucine, L-isoleucine and L-threonine were found to be catalysed by the investigated enzymes, producing L-methionine sulfoxide, 4-hydroxyleucine, 4-hydroxyisoleucine and 4-hydroxythreonine, respectively. An investigation of enzyme kinetics suggested the existence of a novel subfamily of bacterial dioxygenases within the PF10014 family for which free L-amino acids could be accepted as in vivo substrates. A hypothesis regarding the physiological significance of hydroxylated l-amino acids is also discussed....(more)
Smirnov SV, et al. FEMS Microbiol Lett 2012 Jun;331(2):97-104.
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- 24. 4-Hydroxyisoleucine stimulates glucose uptake by increasing surface GLUT4 level in skeletal muscle cells via phosphatidylinositol-3-kinase-dependent pathway.
PURPOSE:
To determine the effect of 4-Hydroxyisoleucine (4-HIL), an unusual amino acid isolated from the seeds of Trigonella foenum-graecum, on glucose uptake and the translocation of glucose transporter 4 (GLUT4) to plasma membrane in skeletal muscle cells and to investigate the underlying mechanisms of action.
METHODS:
Rat skeletal muscle cells (L6-GLUT4myc) were treated with 4-HIL, and the effect on glucose uptake was determined by measuring the incorporation of radio-labeled 2-deoxy-[(3)H]-D-glucose (2-DG) into the cell. Translocation of GLUT4myc to plasma membrane was measured by an antibody-coupled colorimetric assay.
RESULTS:
The prolonged exposure (16 h) of L6-GLUT4myc myotubes to 4-HIL caused a substantial increase in the 2-DG uptake and GLUT4 translocation to the cell surface, without changing the total amount of GLUT4 and GLUT1. Cycloheximide treatment reversed the effect of 4-HIL on GLUT4 translocation to the basal level suggesting the requirement of new protein synthesis. The 4-HIL-induced increase in GLUT4 translocation was completely abolished by wortmannin, and 4-HIL significantly increased the basal phosphorylation of AKT (Ser-473), but did not change the mRNA expression of AKT, IRS-1, GLUT4, and GSK3β.
CONCLUSION:
Results suggest that 4-HIL stimulates glucose uptake in L6-GLUT4myc myotubes by enhancing translocation of GLUT4 to the cell surface in a PI-3-kinase/AKT-dependent mechanism....(more)
Jaiswal N, et al. Eur J Nutr 2012 Oct;51(7):893-8.
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- 25. Expression, purification, crystallization and preliminary X-ray analysis of 4-hydroxy-3-methyl-2-keto-pentanoate aldolase (asHPAL) from Arthrobacter simplex strain AKU 626.
4-Hydroxy-3-methyl-2-keto-pentanoate aldolase (asHPAL), an enzyme used in the synthesis of (2S,3R,4S)-4-hydroxyisoleucine, was crystallized in the absence and the presence of 2-ketobutyrate as one of its substrates by the sitting-drop vapour-diffusion method using PEG 400 as a precipitant. Crystals of asHPAL grown without and with 2-ketobutyrate diffracted to 1.60 and 1.55Å resolution and belonged to space group C2, with unit-cell parameters a = 116.8, b = 88.2, c = 85.3Å, β = 122.3° and a = 116.2, b = 88.1, c = 85.0Å, β = 122.3°, respectively....(more)
Guo L, et al. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012 Aug;68(Pt 8):958-61.
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- 26. Biochemical monitoring in fenugreek to develop functional food and medicinal plant variants.
Many plants used as functional foods or for medicinal purposes have been criticized for their inconsistent physiological effects. Variation in genotype and environmental conditions under which plants are produced can contribute to this inconsistency in biochemical composition. Fenugreek (Trigonella foenum-graecum L.) is a medicinal plant that not only can lower blood glucose and cholesterol levels in animals, but also can be used as a forage crop for livestock feed. Seed content for the bioactive compounds diosgenin, galactomannan and 4-hydroxyisoleucine was characterized for ten fenugreek genotypes under rainfed and irrigated conditions. High and low seed yielding genotype/environment combinations were identified that possessed distinct biochemical and seed production traits. In general high seed yielding genotype/environment combinations exhibited a more stable biochemical composition and consisted largely of irrigated fenugreek. This research indicates that comprehensive biochemical analysis of plant products would facilitate the development of more reliable produce for use by the functional food/medicinal plant industry....(more)
Thomas JE, et al. N Biotechnol 2011 Feb 28;28(2):110-7.
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- 27. A novel L-isoleucine metabolism in Bacillus thuringiensis generating (2S,3R,4S)-4-hydroxyisoleucine, a potential insulinotropic and anti-obesity amino acid.
4-Hydroxyisoleucine (HIL) found in fenugreek seeds has insulinotropic and anti-obesity effects and is expected to be a novel orally active drug for insulin-independent diabetes. Here, we show that the newly isolated strain Bacillus thuringiensis 2e2 and the closely related strain B. thuringiensis ATCC 35646 operate a novel metabolic pathway for L-isoleucine (L-Ile) via HIL and 2-amino-3-methyl-4-ketopentanoic acid (AMKP). The HIL synthesis was catalyzed stereoselectively by an α-ketoglutaric acid-dependent dioxygenase and to be useful for efficient production of a naturally occurring HIL isomer, (2S,3R,4S)-HIL. The (2S,3R,4S)-HIL was oxidized to (2S,3R)-AMKP by a NAD(+)-dependent dehydrogenase. The metabolic pathway functions as an effective bypass pathway that compensates for the incomplete tricarboxylic acid (TCA) cycle in Bacillus species and also explains how AMKP, a vitamin B(12) antimetabolite with antibiotic activity, is synthesized. These novel findings pave a new way for the commercial production of HIL and also for AMKP....(more)
Ogawa J, et al. Appl Microbiol Biotechnol 2011 Mar;89(6):1929-38.
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- 28. Characterization of Bacillus thuringiensis L-isoleucine dioxygenase for production of useful amino acids.
We determined the enzymatic characteristics of an industrially important biocatalyst, α-ketoglutarate-dependent l-isoleucine dioxygenase (IDO), which was found to be the enzyme responsible for the generation of (2S,3R,4S)-4-hydroxyisoleucine in Bacillus thuringiensis 2e2. Depending on the amino acid used as the substrate, IDO catalyzed three different types of oxidation reactions: hydroxylation, dehydrogenation, and sulfoxidation. IDO stereoselectively hydroxylated several hydrophobic aliphatic l-amino acids, as well as l-isoleucine, and produced (S)-3-hydroxy-l-allo-isoleucine, 4-hydroxy-l-leucine, (S)-4-hydroxy-l-norvaline, 4-hydroxy-l-norleucine, and 5-hydroxy-l-norleucine. The IDO reaction product of l-isoleucine, (2S,3R,4S)-4-hydroxyisoleucine, was again reacted with IDO and dehydrogenated into (2S,3R)-2-amino-3-methyl-4-ketopentanoate, which is also a metabolite found in B. thuringiensis 2e2. Interestingly, IDO catalyzed the sulfoxidation of some sulfur-containing l-amino acids and generated l-methionine sulfoxide and l-ethionine sulfoxide. Consequently, the effective production of various modified amino acids would be possible using IDO as the biocatalyst....(more)
Hibi M, et al. Appl Environ Microbiol 2011 Oct;77(19):6926-30.
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- 29. Antihyperglycaemic effect of an unusual amino acid (4-hydroxyisoleucine) in C57BL/KsJ-db/db mice.
The present report confirms the anti-hyperglycaemic and anti-dyslipidemic properties of 4-hydroxyisoleucine, an unusual amino acid isolated from Trigonella foenum-graecum seeds, for the first time in a well-characterised model of type II diabetes, i.e. db/db mice. 4-Hydroxyisoleucine, when given orally to these mice at 50 mg kg(-1) dose level, significantly (p < 0.05) declined their elevated blood glucose, plasma insulin, triglycerides, total cholesterol, low-density lipoprotein-cholesterol levels and raised their declined plasma high-density lipoprotein-cholesterol level. These results indicate that 4-hydroxyisoleucine exhibits significant potential as an anti-diabetic agent by suppressing progression of type II diabetic states that is suggested by enhancement of insulin sensitivity and glucose uptake in peripheral tissue....(more)
Singh AB, et al. Nat Prod Res 2010 Feb;24(3):258-65.
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- 30. An Organocatalyzed enantioselective synthesis of (2S,3R,4S)-4-hydroxyisoleucine and its stereoisomers.
A concise enantioselective total synthesis of (2S,3R,4S)-4-hydroxyisoleucine and its stereoisomers is described. A key feature of this protocol is a catalytic enantioselective mannich reaction that is either anti- or syn-selective as genesis of chirality....(more)
Kumaraswamy G, et al. J Org Chem 2010 Apr 16;75(8):2745-7.
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- 31. Amino acid oxidation of Candida antarctica lipase B studied by molecular dynamics simulations and site-directed mutagenesis.
Molecular dynamics simulations have been performed on lipase B from Candida antarctica (CalB) in its native form and with one or two oxidized residues, either methionine oxidized to methionine sulfoxide, tryptophan oxidized to 5-hydroxytryptophan, or cystine oxidized to a pair of cysteic acid residues. We have analyzed how these oxidations affect the general structure of the protein as well as the local structure around the oxidized amino acid and the active site. The results indicate that the methionine and tryptophan oxidations led to rather restricted changes in the structure, whereas the oxidation of cystines, which also caused cleavage of the cystine S-S linkage, gave rise to larger changes in the protein structure. Only two oxidized residues caused significant changes in the structure of the active site, viz., those of the Cys-22/64 and Cys-216/258 pairs. Site-directed mutagenesis studies were also performed. Two variants showed a behavior similar to that of native CalB (M83I and M129L), whereas W155Q and M72S had severely decreased specific activity. M83I had a slightly higher thermostability than native CalB. No significant increase in stability toward hydrogen peroxide was observed. The same mutants were also studied by molecular dynamics. Even though no significant increase in stability toward hydrogen peroxide was observed, the results from simulations and site-directed mutagenesis give some clues about the direction of further work on stabilization....(more)
Irani M, et al. Biochemistry 2013 Feb 19;52(7):1280-9.
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- 32. Chronic SSRI treatment exacerbates serotonin deficiency in humanized Tph2 mutant mice.
Selective serotonin reuptake inhibitors (SSRIs) are a major class of antidepressants that act by blocking inward transport of serotonin (5-HT) into presynaptic neurons mediated by the serotonin transporter (SERT). Both reuptake and ongoing synthesis are essential in supporting intraneuronal serotonin concentrations in serotonergic neurons. A rare mutation in tryptophan hydroxylase 2 (Tph2), the rate limiting enzyme for 5-HT synthesis, was identified in several patients with major depression, and knock-in mice expressing the analogous mutation (R439H Tph2 KI) show 80% reduction in 5-HT synthesis and tissue levels. Chronic treatment with SSRIs (fluoxetine and paroxetine) resulted in a dramatic further depletion of 5-HT tissue levels in R439H Tph2 KI mice (down to 1-3% of wild type levels) while having little effects in wild-type controls. Treatment with the 5-HT precursor 5-hydroxytryptophan (5-HTP) restored 5-HT tissue content in mutant mice, and cotreatment with 5-HTP and fluoxetine essentially prevented the depleting effect of a chronic SSRI. These data demonstrate that chronic SSRI treatment could further exacerbate the 5-HT deficiency in Tph2 mutation carriers, and this can be prevented by 5-HTP supplementation....(more)
Siesser WB, et al. ACS Chem Neurosci 2013 Jan 16;4(1):84-8.
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- 33. Effects of repeated exposure to MDMA on 5HT1a autoreceptor function: behavioral and neurochemical responses to 8-OHDPAT.
A consistent effect of repeated exposure to 3,4 methylenedioxymethamphetamine (MDMA) is a decrease in the tissue levels of serotonin (5-HT). A variety of behavioural and neurochemical tests were conducted to determine whether the tissue deficits were accompanied by an increased sensitivity of the 5-HT1a autoreceptor. Tests were conducted 2 weeks following MDMA exposure (four injections of 10.0 mg/kg, IP, administered at 2-h intervals in a single day). The response to the 5-HT1a agonist, 8-OHDPAT (0.003-0.5 mg/kg, SC), was assessed using lower lip retraction (LLR), hypoactivity, and 5-hydroxytryptophan (5-HTP) accumulation following decarboxylase inhibition. The 8-OHDPAT produced a dose-dependent increase in LLR and hypoactivity, but these effects were comparable for MDMA and saline pretreated groups. MDMA decreased tissue levels of 5-HT and the accumulation of 5-HTP, but these effects were not reflected in the changes in autoreceptor sensitivity. The data suggest that the decrease in tissue levels of 5-HT produced by MDMA is accompanied by a decrease in tryptophan hydroxylase activity but cannot be explained by supersensitivity of the 5-HT1a autoreceptor....(more)
Schenk S, et al. Psychopharmacology (Berl) 2013 May;227(2):355-61.
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- 34. Spatiotemporal expression pattern of DsRedT3/CCK gene construct during postnatal development of myenteric plexus in transgenic mice.
Cholecystokinin (CCK) is an early marker of both neuronal and endocrine cell lineages in the developing gastrointestinal tract. To determine the quantitative properties and the spatial distribution of the CCK-expressing myenteric neurones in early postnatal life, a transgenic mouse strain with a CCK promoter-driven red fluorescent protein (DsRedT3/CCK) was established. The cell-specific expression of DsRedT3/CCK was validated by in situ hybridization with a CCK antisense riboprobe and by in situ hybridization coupled with immunohistochemistry involving a monoclonal antibody to CCK. A gradual increase in the DsRedT3/CCK-expressing enteric neurones with clear regional differences was documented from birth until the suckling to weaning transition, in parallel with the period of rapid intestinal growth and functional maturation. To evaluate the proportion of myenteric neurones in which DsRedT3/CCK transgene expression was colocalized with the enteric neuronal marker peripherin, immunofluorescence techniques were applied. All DsRedT3/CCK neurones were peripherin-immunoreactive and the proportion of DsRedT3/CCK-expressing myenteric neurones in the duodenum was the highest after the third week of life, when the number of peripherin-immunoreactive myenteric neurones in this region had decreased. Nearly all of the DsRedT3/CCK-expressing neurones also expressed 5-hydroxytryptophan (5-HT). Thus, by utilizing a new transgenic mouse strain, we have demonstrated a small number of CCK-expressing myenteric neurones with a developmentally regulated spatiotemporal distribution. The coexistence of CCK and 5-HT in the majority of these neurones suggests their possible regulatory role in feeding at the suckling to weaning transition....(more)
Máté Z, et al. Cell Tissue Res 2013 May;352(2):199-206.
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- 35. Comparative study of efficacy of l-5-hydroxytryptophan and fluoxetine in patients presenting with first depressive episode.
INTRODUCTION:
Role of l-5-hydroxytryptophan (l-5-HTP) in depression is relatively less studied but the literature has shown its robust role in depression. The present randomized double blind study was undertaken to assess the role of l-5-HTP as an antidepressant and to compare its antidepressant efficacy with fluoxetine in first depressive episode patients of Indian population.
METHODS:
A total of 70 patients of first depressive episode, all of whom were diagnosed with ICD-10 criteria, were recruited but only 60 patients completed the study and were randomly divided into two groups, receiving l-5-HTP and fluoxetine, respectively, for a period of 8weeks. All patients were administered Hamilton Rating Scale for Depression (HAM-D) to assess severity of depression at baseline, 2weeks, 4weeks and 8weeks. The efficacy of treatment was assessed by comparing HAM-D scores obtained at these examinations with the baseline examination; final evaluation of both efficacy and tolerance was assessed using the Clinical Global Impression (CGI) scale at the end of study.
RESULTS:
Both treatment groups showed significant and nearly equal reduction in HAM-D scores beginning at week two and continuing through week eight. Twenty-two patients (73.33%) in the l-5-HTP group and 24 patients (80%) in the fluoxetine group showed positive response at the end of the study.
CONCLUSION:
l-5-HTP has definitely got antidepressant effect in patients of depression. Antidepressant effect was seen within 2weeks of treatment and was apparent in all degrees of depression. The therapeutic efficacy of l-5-HTP was considered as equal to that of fluoxetine.
Copyright © 2012 Elsevier B.V. All rights reserved....(more)
Jangid P, et al. Asian J Psychiatr 2013 Feb;6(1):29-34.
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