-
Min Wei, Ye Lu, Daniel Liu, Wenwen Ru
2014 Volume 37 Issue 9 Pages
1444-1449
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Catalpol, an iridoid glycoside obtained from various natural sources, has many biological functions. However, its ovarian failure-resistant effect has scarcely been studied. The present study used senile 14-month-old Sprague-Dawley female rats to examine the
in vivo ovarian failure-resistant activity of catalpol. Daily oral graded doses of catalpol (1, 3, or 5 mg/kg/d) for 4 weeks significantly increased the levels of serum 17β-estradiol (E
2) and progesterone (P4) but reduced follicle-stimulating hormone and luteinizing hormone levels. Electron microscopic analysis and flow cytometry showed that catalpol significantly retarded apoptosis of the ovarian granulocytes of the rats. These findings suggest that catalpol works on the sex organs by nourishing ovarian tissues and improving both the quality and quantity of follicles, thus leading to rebalanced E
2 and P4 levels in aged rats so that catalpol has a direct
in vivo antiaging effect on the rat ovarian system.
View full abstract
-
Xu Wang, Chongkui Sun, Shiliang He, Xiurong Guo, Hao Xu, Xin Zeng, Lu ...
2014 Volume 37 Issue 9 Pages
1450-1459
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Diosgenyl saponins possess a variety of biological functions. Herein, we demonstrate a new type of diosgenyl saponin derivatives that inhibit cellular proliferation of oral squamous cell carcinoma (OSCC) cell lines. Thereafter, we analyzed these cells’ expression of apoptosis-related proteins. Crucial proteins that participate in apoptosis regulation including caspases 8, 9, and 3, and cleaved Bid were activated and upregulated accompanied by increased concentrations of diosgenyl saponins. Meanwhile, Bcl-2 was downregulated and mitochondrial membrane potential decreased. In our mice model of OSCC, compound 1 showed potent inhibition of solid tumor growth and salient antitumor activity. Diosgenyl β-D-galactopyranosyl-(1→4)-β-D-glucopyranoside might induce OSCC cell line apoptosis through extrinsic and intrinsic pathways, and might provide a mechanistic background for the development of this new type of diosgenylsaponin derivatives into anti-oral cancer agents against OSCC.
View full abstract
-
Toshio Kojima, Xiaofei Wang, Kyoko Fujiwara, Shunzo Osaka, Yukihiro Yo ...
2014 Volume 37 Issue 9 Pages
1460-1465
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Supplementary material
Osteosarcoma is one of the most prevalent bone tumors, occurring mostly in adolescence. However, no noticeable progress has been achieved in developing new therapeutic agents for this disease. Matrix metalloproteinase 9 (MMP9), a type IV collagenase, is a known anticancer target and is overexpressed in osteosarcomas. MMPs can degrade components of the extracellular matrix and are known to be involved in tumor invasion and metastasis. In the present study, we designed and synthesized a pyrrole–imidazole polyamide (HN.49), a gene-silencing agent that specifically targets the nuclear factor-kappa B (NF-κB) binding site of the human MMP9 promoter. We then examined the effect of HN.49 on the enzyme activity of MMP9 and the migration activity of osteosarcoma cells
in vitro. It was clearly shown that HN.49 polyamide reduced the expression level of MMP9 mRNA and the enzymatic activity of MMP-9 in SaOS-2 cells. Moreover, HN.49 polyamide inhibited migration and invasion by SaOS-2 cells in
in vitro wound-closure and matrigel-invasion assays. These results indicate that HN.49 may be a potential therapeutic agent for inhibiting the invasion and metastasis of osteosarcoma.
View full abstract
-
Rong You, Qihua Pang, Lin Li
2014 Volume 37 Issue 9 Pages
1466-1474
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
Advance online publication: July 08, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Supplementary material
Restraint stressed rats were used as a model of
Shanghuo and a global metabolic investigation of the effects of cantonese herbal tea (CHT) on the model rats was then performed by gas chromatography-mass spectrometry (GC/MS) metabonomics in an attempt to characterize the metabolic changes underlying such stress and any protective effects of CHT. Serum and urinary GC/MS profiling of rats exposed to 14 d of successive restraint stress for 6 h every day revealed dramatic changes as evidenced by downregulation of tryptophan metabolism, amino acid metabolism, energy metabolism and perturbation of gut microbiota composition. The administration of CHT to restraint-stressed rats ameliorated the symptoms by upregulation of energy metabolism, amino acid metabolism and modulation of the gut microbiota composition. In addition, CHT-treated rats exhibited a higher level of antioxidant production and a reduction in cholesterol level. The lower level of tryptophan metabolism caused by restraint stress, however, was not completely restored after CHT intake, indicating that the tea did not substantially improve this element. This research indicated that CHT intervention modeled
Shanghuo symptoms of restraint stress through partial regulation of the perturbed metabolic pathways.
View full abstract
-
Osamu Kimura, Koichi Haraguchi, Chiho Ohta, Nobuyuki Koga, Yoshihisa K ...
2014 Volume 37 Issue 9 Pages
1475-1479
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
The uptake mechanism of aristolochic acid I (AAI) was investigated using Caco-2 cells cultured on dishes and permeable membranes. The uptake of AAI from the apical membrane of Caco-2 cells cultured on a dish was rapid, and a decrease in the pH of the incubation medium significantly increased uptake. Incubation at low temperature (4°C) and treatment with sodium azide (a metabolic inhibitor) or carbonylcyanide
p-trifluoromethoxyphenylhydrazone (a protonophore) significantly inhibited the AAI uptake. Coincubation with L-lactic acid or benzoic acid, typical substrates for the proton-linked monocarboxylic acid transporters (MCTs), significantly decreased the AAI uptake, as did coincubation with α-cyano-4-hydroxycinnamate (an inhibitor of MCTs). Dixon plotting revealed the competitive inhibition of benzoic acid on the AAI uptake. To confirm the AAI uptake
via MCTs, the apical-to-basolateral transport of AAI was investigated using the Caco-2 cells cultured on the permeable membranes. The transport of AAI at pH 6.0 was markedly higher than that at pH 7.4, and was significantly decreased by coincubation with benzoic acid. These results suggest that the uptake of AAI from the apical membrane of Caco-2 cells is mediated mainly by MCTs along with benzoic acid.
View full abstract
-
Yang-Suk Yoon, Ma. Easter Joy Villarosa Sajo, Rosa Mistica Coles Ignac ...
2014 Volume 37 Issue 9 Pages
1480-1485
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Atopic dermatitis (AD) is a chronically relapsing, pruritic, eczematous skin disorder accompanying allergic inflammation. AD is triggered by oxidative stress and immune imbalance. In the present study, we investigated the effect of drinking hydrogen water (HW) on 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis in NC/Nga mice and found that HW ameliorated DNCB-induced AD-like clinical symptoms. In line with this, the level of reactive oxygen species in the HW group was significantly inhibited compared with that in the purified water (PW) group. In parallel, HW enhanced glutathione peroxidase activity in DNCB-induced AD as compared with the PW group. Accordingly, the levels of thymus and activation-regulated chemokine and cytokines were significantly decreased in the HW group compared with the PW group. Notably, the levels of Th
2 cytokine, interleukin-5 (IL-5), and proinflammatory cytokines such as tumor necrosis factor-α and IL-6 in HW-fed mice were significantly lower than in control and PW-fed mice. The total serum immunoglobulin E level was also markedly reduced in the HW group. The collective results indicate that HW suppresses DNCB-induced AD in NC/Nga mice
via redox balance and immune modulation and could be a safe clinical fluid treatment for AD.
View full abstract
-
Biswajit Podder, Kyoung Seob Song, Ho-Yeon Song, Yong-Sik Kim
2014 Volume 37 Issue 9 Pages
1486-1494
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Supplementary material
Mucins are highly glycosylated secretary proteins produced by most epithelial cells. Hypersecretion of mucins is one of the prominent symptoms of several airway diseases, including asthma, cystic fibrosis, nasal allergy, rhinitis, and sinusitis. Paraquat (PQ), a common herbicide, has been associated with pulmonary damage and is a potent reactive oxygen species (ROS) producer. However, until now the role of PQ on mucin overproduction has not been studied. The aim of this study is to explore how kaempferol (KM), a widely used dietary flavonoid, affects the protection of human PQ-exposed bronchial epithelium BEAS-2B cells by suppressing
Mucin gene expression
via nuclear factor-kappa B (NF-κB). We observed that PQ generates intracellular ROS, and also induces lipid peroxidation in BEAS-2B cells. Additionally, we found that PQ effectively induces the expression of the
MUC5AC gene; however, co-treatment of PQ with KM drastically reduces its expression. Furthermore, we observed that PQ activates NF-κB, while co-treatment with KM occludes its nuclear translocation, and additionally KM repressed the PQ phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) in BEAS-2B cells. Based on our data, we believe that KM can suppress the over-expression of the
MUC5AC gene. This would contribute to the protection of PQ cytotoxicity to exposed BEAS-2B cells, and allow further study toward a better understanding of ROS-associated diseases.
View full abstract
-
Seung Ho Lee, Min Ji Sung, Hyang Mi Lee, Daehyun Chu, Sang June Hahn, ...
2014 Volume 37 Issue 9 Pages
1495-1504
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
The effects of paroxetine, a selective serotonin reuptake inhibitor, on human ether-a-go-go-related gene (HERG) channels were investigated using the whole-cell patch-clamp technique. The HERG channels were stably expressed in human embryonic kidney cells. Paroxetine inhibited the peak tail currents of the HERG channel in a concentration-dependent manner, with an IC
50 value of 0.45 µM and a Hill coefficient of 0.85. These effects were reversible after wash-out of the drug. The paroxetine-induced inhibition of the HERG channels was voltage-dependent. There was a steep increase in inhibition over the voltage range of the channel opening. Also, a shallow voltage-dependent inhibition was detected over the voltage range in which the channels were fully activated. The fractional electrical distance was estimated to be 0.11. Paroxetine induced a leftward shift in the voltage-dependence of the steady-state activation of the HERG channels. Before and after application of the 1 µM paroxetine, the half-maximum activation was −14.21 mV and −27.04 mV, respectively, with no shift in the slope value. The HERG channel block was not use-dependent. The characteristics of the block were dependent on open and inactivated channel states rather than closed state. Paroxetine had no effect on activation and deactivation kinetics, steady-state inactivation. These results suggest that paroxetine blocks the HERG channels by binding to these channels in the open and inactivated states.
View full abstract
-
Wei He, Bin Wang, Jing Yang, Yun Zhuang, Liangzhi Wang, Xiaodan Huang, ...
2014 Volume 37 Issue 9 Pages
1505-1509
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Autophagy is involved in the activation of hepatic stellate cells (HSCs), which is the key process of liver fibrosis. We reasoned that chloroquine, based on its ability to inhibit autophagy, might exert beneficial effects in liver fibrosis. Liver fibrosis in rats was induced by carbon tetrachloride (CCl
4). Rats were divided into three groups, a normal control group (N group), model group (M group), and chloroquine group (CQ group). Liver fibrosis in the rats was evaluated by hematoxyline–eosin (H&E) and Masson staining. The activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TB) were determined using an automated biochemistry analyzer. Total hepatic hydroxyproline levels were determined with a kit. The expressions of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) were detected by immunofluorescence staining, and the expressions of LC3-II and p62 were determined by Western blotting. Compared with N group, M group showed impaired liver function, liver fibrosis, increased hydroxyproline content, up-regulated expressions of α-SMA and TGF-β1, which have been reported to be pro-fibrogenic genes
in vivo, and increased autophagy flux as indicated by the accumulation of LC3-II and degradation of p62. These changes were attenuated by chloroquine treatment. Chloroquine exerts beneficial effects in CCl
4-induced liver fibrosis. The mechanism of action includes inhibition of autophagy pathways and inhibition of activation of HSCs.
View full abstract
-
Koki Iwata, Kohta Kurohane, Katsuhiro Nakanishi, Masaki Miyake, Yasuyu ...
2014 Volume 37 Issue 9 Pages
1510-1515
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
Advance online publication: July 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Antigen-specific immunoglobulin A (IgA) may be useful for preventing infectious diseases through passive immunization on the mucosal surface. We previously established mouse IgA and IgG monoclonal antibodies (mAbs) specific for the binding subunit of Shiga toxin 1 (Stx1B). We also developed a recombinant hybrid-IgG/IgA, in which variable regions from the IgG mAb were present. The binding activity of recombinant hybrid-IgG/IgA was verified by transient expression. Aiming at a constant supply, we established Chinese hamster ovary cells stably expressing monomeric or dimeric hybrid-IgG/IgA. The cDNAs encoding heavy and light chains were co-expressed for the monomeric hybrid-IgG/IgA, while those encoding heavy, light, and joining chains were co-expressed for the dimeric one. Serum-free culture supernatants of the cloned transfectants were subjected to size-exclusion chromatography. The elution patterns showed that the binding to immobilized Stx1B and the immunoblot signals of assembled immunoglobulins were correlated. In the transfectant for the dimeric hybrid-IgG/IgA, both monomers and dimers were observed. Size-exclusion chromatography enabled us to prepare a sample of the dimeric hybrid-IgG/IgA devoid of the monomeric one. The monomeric and dimeric forms of hybrid-IgG/IgA were prepared from the respective transfectants to examine the neutralization of Stx1. After pretreatment with monomeric or dimeric hybrid-IgG/IgA, the cytotoxicity of Stx1 toward Vero cells was abolished. Furthermore, the dimeric form was more than 10-fold more effective than the monomeric one in terms of toxin neutralization. These results suggest that the tetravalent feature of the binding sites of the dimeric hybrid-IgG/IgA contributes to the efficacy of toxin neutralization.
View full abstract
-
Qiuling Wang, Peigen Xiao, Kun Luo, Jingyuan Song, Shengli Wei, Zaiyou ...
2014 Volume 37 Issue 9 Pages
1516-1524
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
Advance online publication: July 09, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Supplementary material
One hundred and forty-four samples of
Chishao and
Baishao, which represented six species of
Paeonia L. were evaluated for their genetic variation, genetic differentiation and phylogenetic relationship, based on the nuclear ribosomal DNA internal transcribed spacer (ITS) region. Samples from representative of the population were then used to do a cultivation comparison experiment, and then to identify the contents of the active ingredients. The results showed there were differences in the haplotype distribution and frequency between populations of
Chishao and
Baishao. An analysis of molecular variance (AMOVA) indicated statistically significant (
p<0.001) genetic differentiation between the populations of wild and cultivated
Paeonia lactiflora PALL. The albiflorin content between
Chishao and
Baishao was also significantly different (
p<0.05). All the results clearly illustrate that currently cultivated
P. lactiflora cannot be used as a substitute for
Chishao.
View full abstract
-
Hui-Hua Qu, Ye Sun, Ting-Ting Wu, Gui-Liang Zhang, Jin-Jun Cheng, Xue- ...
2014 Volume 37 Issue 9 Pages
1525-1533
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Geniposide, Geniposide, the main active component in extracts of
Gardenia jasminoides ELLIS., is one of the main components of Huanglian-Jiedu-Tang (HJT). This study aimed to validate an indirect competitive enzyme-linked immunosorbent assay (icELISA) based on monoclonal antibodies (mAb) against geniposide (anti-geniposide mAb), which was developed by our lab, and apply the assay to study the pharmacokinetics of geniposide in HJT in mice. Blood samples were drawn from mice at predetermined time points after oral administration of HJT in three dosages. A linear correlation was obtained for geniposide concentrations in the range from 1.17 to 37.50 µg/mL. The intra-day and inter-day precision values of the icELISA method were well within the recommended range (≤10%). The recovery rates ranged from 99.74 to 102.40%. Stability studies showed that geniposide sample solutions were intact for 12 h. The
Tmax and mean residence time (MRT) of geniposide of the three groups were consistent with previous data. The results suggest that a reliable and effective method was established and could be applied to the study of the pharmacokinetics of geniposide in HJT.
View full abstract
-
Nattisa Niyomtham, Nuttapon Apiratikul, Kanyarat Chanchang, Praneet Op ...
2014 Volume 37 Issue 9 Pages
1534-1542
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Lipid-mediated delivery of DNA into cells holds great promise both for gene therapy and basic research applications. The primary approach to improving transfection efficiency is the design and synthesis of novel cationic lipids. Alternatively, using the synergistic effect of different cationic mixtures can provide another approach to increasing transfection efficiency. This paper describes the synergistic effect of lipids with different polarheads, central core structures and hydrophobic tails. The enhancement of cellular transfection into HEK293 cells was observed by combining two lipids having aminoglycerol and di(hydroxylethyl)amino core structures at a 1 : 1 weight ratio. Additionally, the liposome formation of these lipids with the helper lipid, 1,2-dioleoyl-propyl-3-phosphatidylethanolamine (DOPE), at the weight ratio of 1 : 1 can provide higher transfection efficiency into HEK293, MCF-7 and HeLa cells than Lipofectamine™ 2000. Our finding indicated that cationic liposomes comprised of a mixture of lipids with different polarheads, central core structures and hydrophobic tails should be very promising in liposome-mediated gene delivery
in vitro and
in vivo.
View full abstract
-
Sureewan Duangjit, Praneet Opanasopit, Theerasak Rojanarata, Jun Takay ...
2014 Volume 37 Issue 9 Pages
1543-1549
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
Advance online publication: July 09, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
A nonlinear response surface method incorporating multivariate spline interpolation (RSM-S) is a useful technique for the optimization of pharmaceutical formulations, although the direct reliability of the optimal formulation must be evaluated. In this study, we demonstrated the feasibility of using the bootstrap (BS) resampling technique to evaluate the direct reliability of the optimal liposome formulation predicted by RSM-S. The formulation characteristics (
Xn), including vesicle size (
X1), size distribution (
X2), zeta potential (
X3), elasticity (
X4), drug content (
X5), entrapment efficiency (
X6), release rate (
X7), and the penetration enhancer (PE) factors as formulation factors (
Zn), with the type of PE (
Z1) and content of PE (
Z2) were used as causal factors of the response surface analysis. The intended responses were high skin permeability (flux,
Y1) and high stability formulation (drug remaining,
Y2). Based on the dataset obtained, the simultaneous optimal solutions were estimated using RSM-S. Leave-one-out-cross-validation showed satisfying reliability of the optimal solution. Concurrently, similar BS optimal solutions were estimated from the BS dataset that was generated from the original dataset through BS resampling at frequencies of 250, 500, 750, and 1000. The analysis and simulation indicated that
X4,
X5, and
Z2 were the prime factors affecting
Y1 and
Y2. These findings suggest that this approach could also be useful for evaluating the reliability of an optimal liposome formulation predicted by RSM-S and would be beneficial for the pharmaceutical development of liposomes for transdermal drug delivery.
View full abstract
-
Yuji Mukai, Takaki Toda, Toru Hayakawa, Erik Eliasson, Anders Rane, No ...
2014 Volume 37 Issue 9 Pages
1550-1554
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
The present study aimed to characterize the inhibitory effects of losartan, an angiotensin II receptor blocker, on CYP2C8. Inhibition experiments were based on human lymphoblast-expressed recombinant CYP2C8 (rCYP2C8) and paclitaxel as a CYP2C8 substrate. The disappearance of paclitaxel (initial concentration: 7.5 µmol/L) was monitored over time at different concentrations of losartan (0, 100, 500 and 1000 µmol/L). For Dixon and Cornish–Bowden plots, various concentrations of losartan (final concentration: 0, 50, 100 and 250 µmol/L) and paclitaxel (final concentration: 3.75, 7.5 and 15 µmol/L) were used. Losartan exhibited significant inhibitory effects on paclitaxel disappearance at losartan concentrations of ≥100 µmol/L (
p<0.05). Losartan at 50 µmol/L inhibited the disappearance of paclitaxel by about 60%. Both plots showed that losartan exerted competitive inhibition of rCYP2C8, and its apparent
Ki value was estimated to be 40.7 µmol/L. The degree of inhibition (
R value) for rCYP2C8 after oral administration of losartan (100 mg) was estimated to be 1.2, using the maximum hepatic input total blood concentration (7.3 µmol/L). The present results show that losartan acts as a competitive inhibitor of CYP2C8-dependent drug metabolism
in vitro. Subjects with a low clearance of losartan, resulting in a high average systemic blood concentration of losartan after repeated oral administration, should be carefully monitored for possible adverse reactions during co-medication with CYP2C8 substrate drugs.
View full abstract
-
Junko Kimura, Kiyomitsu Nemoto, Masakuni Degawa, Akihito Yokosuka, Yos ...
2014 Volume 37 Issue 9 Pages
1555-1558
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
Advance online publication: June 26, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
The
N-methyl-D-aspartate (NMDA) receptor plays a key role in learning and memory. Our recent studies have shown that nobiletin from citrus peels activates the cAMP response element-binding protein (CREB) signaling pathway and ameliorates NMDA receptor antagonist-induced learning impairment by activating extracellular signal-regulated kinase. For the first time, we have shown that nobiletin significantly upregulated mRNA expression of the NMDA receptor subunits NR1, NR2A, and NR2B in PC12D cells. Furthermore, c-Fos mRNA expression also increased due to the action of nobiletin. Our results indicate that nobiletin modulates the expression of essential genes for learning and memory by activating the CREB signaling pathway, and suggest that this action mechanism of nobiletin plays a crucial role in improving NMDA receptor antagonist-induced learning impairment in model animals with dementia.
View full abstract
-
Kakuyou Ogawa, Takashi Miyoshi, Takashi Kitayama, Michiho Ito
2014 Volume 37 Issue 9 Pages
1559-1563
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Supplementary material
Zerumbone
1 is an 11-membered cyclic sesquiterpene obtained from the rhizomes of
Zingiber zerumbet SMITH (Zingiberaceae). In this study, we investigated the structure–activity relationship of
1, α-humulene (
2), tetrahydrozerumbone stereoisomers (
3–
5), and tetrahydrozerumbone derivatives (
6–
9). The oxygen-containing functional groups and the configurations at C1 and C2 contributed to the spontaneous locomotor activity reduction of zerumbone
1 and derivatives
2–
9.
View full abstract
-
Motohiro Nishimura, Yoshio Nishimura, Chinatsu Abe, Mayuko Kohhata
2014 Volume 37 Issue 9 Pages
1564-1568
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
Advance online publication: July 09, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
Vanillate is converted to protocatechuate by an
O-demethylase consisting of VanA and VanB in
Streptomyces sp. NL15-2K. In this study, vanillate demethylase from this strain was functionally expressed in
Escherichia coli, and its substrate range for vanillate analogs was determined by an
in vivo assay using recombinant whole cells. Among aromatic methyl ethers, vanillate, syringate,
m-anisate, and veratrate were good substrates, whereas ferulate, vanillin, and guaiacol were not recognized by
Streptomyces vanillate demethylase. After vanillate, 4-hydroxy-3-methylbenzoate was a better substrate than
m-anisate and veratrate, and the 3-methyl group was efficiently oxidized to a hydroxymethyl group. These observations suggest that the combination of a carboxyl group on the benzene ring and a hydroxyl group in the
para-position relative to the carboxyl group may be preferable for substrate recognition by the enzyme.
1H-NMR analysis showed that the demethylation product of veratrate was isovanillate rather than vanillate. Therefore, it was concluded that
O-demethylation of veratrate by
Streptomyces vanillate demethylase occurred only at the
meta-position relative to the carboxyl group.
View full abstract
-
Hitoshi Ueno, Ryo Shimizu, Tomofumi Okuno, Hirofumi Ogino, Tomohiro Ar ...
2014 Volume 37 Issue 9 Pages
1569-1574
Published: September 01, 2014
Released on J-STAGE: September 01, 2014
JOURNAL
FREE ACCESS
FULL-TEXT HTML
The effects of administering the selenocompounds, sodium selenite, methylseleninic acid (MSA), and seleno-L-methionine (SeMet) on glucose tolerance were compared in the nicotinamide (NA) and streptozotocin (STZ)-induced diabetic mouse model. ICR mice were intraperitoneally treated twice with STZ (100 mg/kg) 15 min after an injection of NA (120 mg/kg) at a 1-d interval. Non-fasting blood glucose levels were then monitored weekly while orally administering the selenocompounds at 158 µg Se/kg body weight with free access to a selenium-deficient diet for 5 weeks. The mean body weights of NA/STZ-induced diabetic mice were partly restored by the administration of selenocompounds, while SeMet led to a higher selenium content and glutathione peroxidase 1 activity in the pancreas. Non-fasting and oral glucose tolerance-tested blood glucose levels, which were elevated by NA/STZ, were significantly suppressed by the administration of SeMet. These results suggest that SeMet may improve glucose tolerance in a NA/STZ-induced mild diabetic mouse model by increasing bioavailability in the pancreas.
View full abstract