“Neuronal activity”-dependent transcriptional activation is required for the long-lasting, functional changes that are involved in memory consolidation or drug addiction. Elucidation of the molecular mechanisms underlying the neuronal activity-dependent transcription of synaptic plasticity-related genes has helped towards understanding neuronal function and disorders as well in identifying new target molecules for drug design. In this study, we focused on neurotrophin and neuropeptide, which both have the ability to modulate neuronal survival and function. We also examined the molecular mechanisms by which underlying neurotrophin genes are regulated by neuronal activity. Brain-derived neurotrophic factor (BDNF) is a neurotrophin family member that has important roles in neuronal survival and plasticity as well as in psychiatric disorders. Transcriptional activation of the BDNF gene is commonly regulated by a key transcription factor, cAMP response element-binding protein (CREB), and this at least in part contributes to neuronal activity-dependent neuronal survival. Among at least four distinct promoters of the BDNF gene, promoters I and III are differentially activated by Ca2+ signals via NMDA receptors and L-type voltage-dependent Ca2+ channels. Especially, BDNF gene promoter I activation requires the cooperative binding of and upstream stimulatory factor (USF) and CREB to a CRE/USF binding site. By contrast, NT-3 gene transcription is regulated by Sp3/4. An important future direction will be to elucidate how long-lasting changes in neuronal plasticity are “epigenetically” and “structurally” controlled. Our studies on the relationships between long-lasting neuronal responses and gene expressions should help guide research into novel drugs for neuronal or psychiatric disorders.
A highly sensitive flow injection fluorometry for the determination of albumin was developed and applied to the determination of albumin in human bronchoalveolar lavage fluids (BALF). This method is based on binding of chromazurol S (CAS) to albumin. The calibration curve was linear in the range of 5—200 μg/ml of albumin. A highly linear correlation (r=0.986) was observed between the albumin level in BALF samples (n=25) determined by the proposed method and by a conventional fluorometric method using CAS (CAS manual method). The IgG interference was lower in the CAS flow injection method than in the CAS manual method. The albumin level in BALF collected from healthy volunteers (n=10) was 58.5±13.1 μg/ml. The albumin levels in BALF samples obtained from patients with sarcoidosis and idiopathic pulmonary fibrosis were increased. This finding shows that the determination of albumin levels in BALF samples is useful for investigating lung diseases and that CAS flow injection method is promising in the determination of trace albumin in BALF samples, because it is sensitive and precise.
Although thalidomide was withdrawn due to teratogenicity and neuropathy, there is now growing clinical interest in this compound because of its immunomodulatory and anti-angiogenic properties. In 1998, thalidomide was approved by the U.S. Food and Drug Administration for the treatment of erythema nodosum leprosum (ENL), an inflammatory complication of Hansen's disease, through a restricted-use program. Thalidomide was approved for the treatment of relapsed or refractory multiple myeloma (MM) as an orphan drug in Japan. Direct deproteinization method was shown to be useful for quantitation of enantioselective thalidomide blood level. Stabilized blood was deproteinized with methanol and 2 m trichloroacetic acid. The supernatant was injected onto reverse-phase column (CHIRALPAK AD-RH). The mobile phase consisted of 10% acetonitrile, 70% methanol and 20% 0.025 m citrate buffer (pH 3.0), and the flow rate was 0.5 ml/min. Wavelength of detection was 220 nm. (−)-(S)-thalidomide and (+)-(R)-thalidomide were separated at 13.5 min and 17.6 min, respectively. The accuracy of this method was almost the same as that of the measurement technique with extraction and concentration. In clinical practice, MM patients usually take many kinds of drugs at the same time. Actually, this patient takes a lot of drugs with thalidomide. However, we found no interference of these drugs and thalidomide on the chromatogram. This simple and reliable HPLC determination method for both enantiomers of thalidomide is thought to be very useful for thalidomide studies.
A method for predicting bioactive candidates in herbal medicines (HMs) was developed using four types of target cell extraction followed by high performance liquid chromatography coupled with diode array detection-mass spectrometry (HPLC-DAD-MS) analysis. Through the proposed method, some potential bioactive components in Radix Salviae miltiorrhizae, a widely used HM for the treatment of cardiovascular diseases, were screened in view of interacting with endothelial cells, myocardial cells, blood platelets and red cells. Specifically, eleven compounds were detected in the desorption eluate of endothelial cells, nine in myocardial cells, fifteen in blood platelets and five in red cells. Totally, sixteen compounds were detected and fourteen of them were identified qualitatively in terms of their MS spectra and in comparison with some of the reference compounds. The results indicate that the proposed method may be applied to prediction of the bioactive multi-compounds in HMs.
Biotin-binding IgG (B-IgG) in human sera was quantified using previously developed F(ab′)2anti-human IgG-coated multiwell microplates (Muratsugu M. et al., 2003, Biol. Pharm. Bull., 26, 1605—1608). The levels of B-IgG in sera, however, were higher than those we predicted. In this study, we modified the assay using F(ab′)2anti-human IgG-coated multiwell microplates and successfully quantified the levels of B-IgG in sera. The cause of the unpredicted results was discussed in the text. In addition, the levels of biotin-binding IgA (B-IgA) and IgM (B-IgM) in sera could be measured using F(ab′)2anti-human IgA- or IgM-coated multiwell microplates. We quantified B-IgG, B-IgA, and B-IgM in sera from healthy specimens and patients with bronchial asthma, atopic dermatitis, epilepsy, and juvenile rheumatoid arthritis.
We examined the correlations between serum dolichol levels and laboratory test parameters in patients affected by disease, as well as the distribution of dolichol in sera from patients with hyperbetalipoproteinemia and hyperalphalipoproteinemia. Serum dolichol was evaluated by a reverse-phase HPLC method. After centrifugation, the serum dolichol found in healthy controls was mainly associated with medium-sized particles of the high-density lipoprotein (HDL) fraction. For patients with hyperbetalipoproteinemia, serum dolichol was also associated with the medium HDL fractions. However, for hyperalphalipoproteinemia patients the levels of large HDL and serum dolichol were increased, and serum dolichol was mainly associated with the large HDL fraction. On laboratory tests of components, the dolichol level was not correlated with the values for markers of the liver and biliary system, with the values of renal function markers, with creatine kinase activity, amylase activity or uric acid concentration, but was correlated with total cholesterol, HDL-cholesterol and apoA-I concentrations, and with lactate dehydrogenase (LDH) activity. These results suggest that serum dolichol exclusively localized in HDL, and in subpopulation, that in normocholesterolemia or hyperbeta-cholesterolemia is associated with HDL3, which is small sized and high density HDL, however, that in hyperalphacholesterolemia is associated with HDL2, which is large sized and lower density HDL.
We determined the effects of psychotropic drugs on the cytochrome P450 2D (CYP2D)-mediated 21-hydroxylation of progesterone (PROG) and allopregnanolone (ALLO) with the goal of clarifying whether neurosteroid levels are affected by psychotropic drugs in the brain. PROG or ALLO was incubated with rat CYP2D4 or human CYP2D6 in the presence of typical psychotropic drugs, fluoxetine, imipramine, desipramine, mazindol, and GBR12909, and the 21-hydroxylated metabolites of PROG and ALLO were determined by high performance liquid chromatography and liquid chromatography-tandem mass spectrometry, respectively. Fluoxetine competitively inhibited CYP2D4-mediated PROG 21-hydroxylation and increased both Km and Vmax values of CYP2D6-mediated PROG 21-hydroxylation. In addition, fluoxetine competitively inhibited ALLO 21-hydroxylation mediated by CYP2D4 and CYP2D6. Imipramine, desipramine, mazindol, and GBR12909 competitively inhibited PROG 21-hydroxylation mediated by CYP2D4 and/or CYP2D6, and all psychotropic drugs inhibited ALLO 21-hydroxylation mediated by CYP2D4 and/or CYP2D6. The inhibition constants (Ki values) of imipramine, desipramine, and mazindol against the 21-hydroxylation of PROG and ALLO by CYP2D6 were lower than those by CYP2D4. These results indicate that psychotropic drugs including fluoxetine affected the metabolism of neurosteroids, such as PROG and ALLO in the brain, suggesting that the regulation of the neurosteroid levels is modified by central nervous system-active drugs that inhibit brain CYP2D isoforms.
A biotin-conjugated photoactivatable phenylaminodiazirine derivative of 2,3-didehydro-2-deoxy-N-acetylneuraminic acid (DANA) was synthesized to identify sialidase. The free carboxylic group and N-acetyl substituent of sialic acid, which are important for recognition and enzymatic activity of sialidase, were conserved by the photolabeling compound as confirmed using analytical methods. The synthesized compound and DANA competitively inhibited starfish sialidase with a Ki value of 7.6 μM and 4.6 μM, respectively. Photo incorporation of the labeling compound to sialidase increased with irradiation time; 90% photo incorporation was achieved with more than 10-min irradiation, and labeling was completely inhibited by the addition of a competitive inhibitor. Starfish sialidase purified using high-performance gel filtration chromatography was subjected to photoaffinity labeling. A 50-kDa band was revealed to contain the sialidase active site by the photolabeling compound, and labeling was completely hindered in presence of the competitive inhibitor. Labeling specificity was ensured by the addition of the heat-deactivated standard protein chymotrypsinogen A to the reaction mixture.
Aromatase, a key steroidogenic enzyme that catalyses the conversion of androgens to estrogens, present a target for endocrine disrupting chemicals. However, little is known about the effect of pollutants on aromatase enzymes. In this study, we first optimized a non-radioisotope aromatase assay using rat ovarian microsomes in vitro and measuring the estrone level with an enzyme-linked immunosorbent assay (EIA method). The sensitivity of the EIA method was about ten times as high as that of the radioisotope (RI) method. A significant positive correlation was indicated between EIA and RI method. We used this EIA assay system to investigate the effects of aromatase activity on 45 chemicals that had previously been reported to act as endocrine disruptors or to have the possibility of having such an effect. Six of the chemicals, rose bengal, erythrosine, phloxine, allura red, gallic acid, and tributyltin, inhibited aromatase activity. The inhibitory effect of rose bengal was the strongest (IC50=2.4×10−8 M), and its strength of inhibition was about 100 times that of a known aromatase inhibitor, 4-hydroxy-androstenedione (IC50=2.6×10−6 M) but was about 1/25 that of fadrazole (IC50=1.0×10−9 M). It is thought that this EIA method would be useful for measuring the aromatase activity of microstructures.
Matrix metalloproteinase-9 (MMP-9) is involved in atherogenesis, and the production of MMP-9 in macrophages is considered to be mediated by the arachidonic acid cascade. The present study examined the possible involvement of group IVA phospholipase A2 (IVA-PLA2), a key enzyme in the arachidonic acid cascade, in the production of MMP-9 induced by oxidized low-density lipoprotein (oxLDL) in macrophages and high-fat diet-induced formation of atherosclerotic lesions using IVA-PLA2-deficient mice (C57BL/6 background). In wild-type mouse peritoneal macrophages, oxLDL induced an increase in MMP-9 in the culture medium. The oxLDL-promoted production of MMP-9 was markedly reduced in IVA-PLA2-deficient macrophages compared to wild-type macrophages. Feeding of wild-type mice with a high-fat diet caused the formation of early atherosclerotic lesions in the aortic root with increases in MMP-9 and macrophages in the lesions and with higher serum levels of total cholesterol. Such lesions were apparently less severe in IVA-PLA2-deficient mice fed a high-fat diet, despite higher total cholesterol levels. Under the conditions, a high-fat diet reduced the serum levels of high-density lipoprotein-cholesterol (HDL-C) in wild-type mice. However, IVA-PLA2-deficient mice fed a high-fat diet were protected against the decrease in HDL-C levels. The present results suggest that IVA-PLA2 is involved in the oxLDL-induced production of MMP-9 in macrophages and the high-fat diet-induced formation of early atherosclerotic lesions. The protection against the lesions in IVA-PLA2-deficient mice may be ascribable, in part, to the impaired production of MMP-9 and/or the maintained levels of HDL-C.
In this study, the authors evaluated the possible use of 3-hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) in anti-leukemic chemotherapy. Cytotoxic potency against HL-60 was as follows; simvastatin (SV)>atorvastatin>cerivastatin>fluvastatin. Interestingly, HL-60-R2, an all-trans retinoic acid (ATRA)-resistant HL-60 variant, was twice as sensitive to SV than HL-60. Further studies revealed the particular mechanism of action of SV-induced apoptosis in leukemia. SV directly and rapidly disordered mitochondria with a loss of its membrane potential, reactive oxygen species (ROS) generation and subsequent irreversible damage with cytochrome c leakage and, finally, SV induced apoptosis through caspase-9 activation, whereas several studies have shown that other statins induced apoptosis to leukemia by the depletion of isoprenoids used for the prenylation of small GTPases, which are essential for cellular signal transduction. Our findings suggest that the mitochondrial pathway plays an important role in the higher potency of SV as a new class of agents for anti-leukemic therapy alone and/or in combination with agents.
Disposable gloves made of nitrile-butadiene rubber (NBR) are used for contact with foodstuffs rather than polyvinyl chloride gloves containing di(2-ethylhexyl)phthalate (DEHP), because endocrine-disruptive effects are suspected for phthalate diesters including DEHP. However, 4,4′-butylidenebis(6-t-butyl-m-cresol) (BBBC), 2,4-di-t-butylphenol, and 2,2,4-trimetyl-1,3-pentanediol diisobutyrate can be eluted from NBR gloves, and possibly also detected in food. In this study, we examined the endocrine-disrupting effects of these chemicals via androgen receptor (AR) and estrogen receptor (ER)-mediated pathways using stably transfected reporter gene cell lines expressing AR (AR-EcoScreen system) and ER (MVLN cells), respectively. We also examined the binding activities of these chemicals to AR and ER. The IC50 value of BBBC for antagonistic androgen was in the range of 10−6M. The strength of inhibition was about 5 times that of a known androgen antagonist, 1,1′-(2,2-dichloroethylidene)bis[4-chlorobenzene] (p,p′-DDE), and similar to that of bisphenol A. The IC50 value of BBBC for antagonistic estrogen was in the range of 10−6M. These results suggest that BBBC and its structural homologue, 4,4′-thiobis(6-t-butyl-m-cresol) are androgen and estrogen antagonists. It is therefore necessary to study these chemicals in vivo, and clarify their effect on the endocrine system.
We previously demonstrated the existence of a minor 130 kDa subunit in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)/Western blot analysis of monkey liver cytosol and expressed monkey aldehyde oxidase (AO) in Escherichia coli. In contrast, the 130 kDa subunit was not observed in rat AO. In the current study, the properties of the 130 kDa subunit were investigated from the viewpoint of species differences in the presence of the subunit and AO activity. Monkey AO with His-tag at the N- and C-terminus were expressed, and were immunoanalyzed with anti-AO and anti-His-tag antisera. The results revealed that the minor 130 kDa subunit was produced by cleavage at the N-terminal side of the 150 kDa subunit. The cleavage point was shown to be located between 188Leu and 189Pro of 150 kDa AO subunit by the Edman degradation method. The two amino acids related to the cleavage are contained in the linkage between the 2Fe–2S and FAD domains in AO of human and monkey, but not in AO of rat and mouse. As a fact, the 130 kDa subunit was observed in AO of human and monkey, but not in AO of rat and mouse, suggesting the two amino acids might be one reason of a species difference in the formation of the 130 kDa subunit. However, the existence of the 130 kDa subunit is not associated with the species differences in AO activity, because the cleavage results in the loss of 2Fe–2S cluster domain essential for exertion of AO activity.
Alveolar epithelial cell death plays a crucial role in the progression of acute lung injury. We have demonstrated up-regulation of Fas expression on alveolar epithelial cells, and soluble Fas ligand secretion from inflammatory cells upon acute lung injury. Here we show that the lipopolysaccharide-stimulated human monocyte cell line THP-1 releases Fas ligand, and that conditioned medium from lipopolysaccharide-stimulated THP-1 cells induces apoptosis of the human pulmonary adenocarcinoma cell line A549. Activation of caspase-3 and -8 is associated with the apoptosis. Gene targeting on Fas in A549 cells by specific small interfering RNA impairs apoptosis induced by conditioned medium from activated THP-1, while that on Fas ligand in THP-1 cells impairs the apoptosis-inducing activity of the conditioned medium produced by lipopolysaccharide-stimulated cells. These results suggest that Fas ligand released by monocytes causes alveolar epithelial cell death through a Fas-dependent apoptotic mechanism in the development of acute lung injury.
Ewing's sarcoma (ES) is one of the most malignant tumors of bone and soft tissue in children and young adults. ES belongs to a group of small round cell tumors (SRCTs) that also includes neuroblastoma, rhabdomyosarcoma, and malignant lymphoma. However, ES exhibits several specific chimeric genes (EWS–FLI1, EWS–ERG, EWS–ETV1, EWS–E1AF, and EWS–FEV) caused by chromosomal translocations that are not shared by other SRCTs. These chimeric genes regulate the expression of various other genes; that is, they activate inhibitors of DNA binding 2 (Id2) gene expression or they suppress transforming growth factor β II (TβRII) receptor gene expression. The regulation of these chimeric genes may affect critical cell signal transductions, such as signals involved in cell cycle and apoptosis in ES tumor cells. Using an antisense oligodeoxynucleotide against a sequence containing the ATG initiation codon of the EWS–FLI1 chimeric gene that specifically reacts with the EWS–FLI1 and EWS–ERG chimeric genes, we were able to regulate the cell cycle through the down-regulation of Id2. Here, we report that treatment with an antisense oligodeoxynucleotide against this chimeric gene was very useful for inducing the regression of ES tumor growth; thus, this chimeric gene may be an important target for the treatment of ES patients.
In order to elucidate the role of the system L-type amino acid transporters (LATs) in the wound healing process of aged and young subjects, we investigated the expression of LAT1, LAT2 and their subunit 4F2hc in the skin healing process after artificial wounds of dorsal skin in the young and old rats. Methods: The 1 cm full-thickness incisional wounds were made through the skin and panniculus carnosus muscle. The wounds were harvested at days 1, 3, 5 and 7 post-wounding, the experimental controls were harvested the skin of rat without wounds and the various analyses were performed. Results: In young rats, gradually and noticeable wound healing was detected, however, in old rats, wound healing was found to be greatly delayed. In young rats, the expression of LAT1 was increased rapidly on the day 1 after wound induction, on the other hand, in old rats, the expression of LAT1 after wound induction was not different from the control group. In young rats, the expression of LAT2 after the induction of wound was not different from the control group, however in old rats, the expression of LAT2 on the day 1 of wound induction was rapidly elevated. Conclusion: These results suggest that the LAT1 and LAT2 increase in the wound healing process after cell injury in young and old rats, respectively.
To investigate chemopreventive effect of liposomal β-sitosterol on tumor metastasis, we prepared liposomal β-sitosterol composed of egg yolk phosphatidylcholine for oral delivery. Although orally administered β-sitosterol (4 μmol as β-sitosterol/mouse) was not absorbed into plasma, the amount of immune response cytokines such as IL-12 and IL-18 was increased in the small intestine after the liposome intake. Moreover, after daily oral administration of the liposome for 7 d, natural killer (NK) cell activity in the mice was increased, suggesting that the immune surveillance activity of mice was enhanced by the liposomal β-sitosterol intake. Thus, we examined metastatic potential of B16BL6 melanoma cells, which were intravenously injected into mice after sequential administration of liposomal β-sitosterol for 7 d. The number of metastatic colonies in the lungs was significantly less than that of control group two weeks after the injections of the cells. These results suggest that daily liposomal β-sitosterol intake prevents tumor metastasis may be due to enhancement of gut immune surveillance systems.
Familial juvenile hyperuricemic nephropathy (FJHN) and medullary cystic kidney disease type 2 (MCKD2) are autosomal dominant disorders characterized by juvenile hyperuricemia of the underexcretion type, juvenile gout and chronic renal failure in the adult. FJHN/MCKD2 constitute diseases caused by mutations of the human uromodulin (UMOD) gene that encodes uromodulin, the most abundant glycoprotein in normal human urine. The mutations affect the transport of uromodulin, resulting in the accumulation of uromodulin in the kidneys of FJHN/MCKD2 patients. The purpose of this study was to confirm the accumulation of uromodulin in the kidneys of transgenic mice harboring the mutant human UMOD gene with mouse UMOD gene promoter, and to determine the relationship between its accumulation and the effect on uromodulin transport. The mutant human UMOD mRNA and its protein were expressed in the kidneys of transgenic mice. Moreover, the staining of human uromodulin was colocalized with that of mouse uromodulin. Although the human UMOD mRNA levels increased, the protein levels did not change and the accumulation of human uromodulin was not observed. However, the mouse uromodulin consists of two forms, 103 and 117 kDa, and the 103 kDa protein was gradually increased in the kidneys of transgenic mice. Human and mouse uromodulins in the kidneys of transgenic mice were mainly detected in the Triton X-100 insoluble microsomal fraction. Therefore, the progressive accumulation of uromodulin was observed in the plasma membrane of the kidneys of transgenic mice but the accumulated uromodulin protein was not that encoded by the transgene.
To determine the role of nitric oxide (NO) in rat liver transporter regulation, we investigated whether NO mediates lipopolysaccharide (LPS)-induced changes in transporters and their transcription factor expression using aminoguanidine (AG), an inhibitor of induced nitric oxide synthase (iNOS). We confirmed that LPS decreased mRNA levels for Ntcp, Oatp1, Oatp2, Oatp4, Oct1, Mrp2, Mdr1a and increased those for Mdr1b at 16 h after administration. AG attenuated these decreases for Ntcp, Oatp1 and Oatp4 (retinoid X receptor (RXR)α- and hepatocyte nuclear factor (HNF)4α-dependent genes) and increase for Mdr1b (nuclear factor (NF)-κB-dependent gene). Concomitantly, it suppressed LPS-induced NF-κB-dependent gene transcription, such as those for proinflammatory cytokines (cytokines; tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6) and iNOS, and also suppressed IL-1β release from Kupffer cells (KCs) at post-translational levels, but had little effect on the LPS-induced decreases in RXRα and HNF4α transcriptional activities. These findings indicate that hepatocytes were stimulated directly by LPS, which lead to the activation of NF-κB and reduction of RXRα and HNF4α transcriptional activities as early responses, and indirectly by cytokines and NO released from KCs via activation of NF-κB by LPS as delayed responses. We conclude that AG, which suppresses LPS-induced NF-κB activation in both hepatocytes and KCs and then the release of cytokines and NO from KCs, attenuates LPS-induced changes of Ntcp, Oatp1, Oatp4 and Mdr1b transcription in hepatocytes. The roles of cytokines and NO could not be distinguished, however. Further in vitro study is needed to clarify the role of NO in transporter regulation.
Trehalose, a nonreducing disaccharide which accumulates dramatically during stationary phase or under oxidative stress, is well known as a stress protectant in several organisms. Here we investigated the putative correlation of trehalose with Cap1p, which is a basic region-leucine zipper (bZip) transcription factor participating in oxidative stress tolerance in Candida albicans. HPLC-MS analysis showed that trehalose did not accumulate in the cap1/cap1 mutant during stationary phase. When the mutant was exposed to high concentration of H2O2, trehalose accumulation was still not induced. Under both of the conditions above, the cap1/cap1 mutant showed high sensitivity to H2O2, and the cell viability was rather low. Furthermore, when exogenous trehalose was added to the culture of the cap1/cap1 mutant, the tolerance of this strain to oxidative stress was increased. Real time reverse transcription polymerase chain reaction (RT-PCR) analysis revealed that the transcript levels of TPS2 and TPS3 were increased in the wild type strain compared to that in cap1/cap1 mutant when exposed to H2O2. These results indicated that trehalose accumulation is important to the oxidative stress tolerance mediated by Cap1p in C. albicans.
Using a plaque reduction assay, treatment of human influenza A viruses with the fruit-juice concentrate of Japanese plum (Prunus mume SIEB. et ZUCC) showed strong in vitro anti-influenza activity against human influenza A viruses before viral adsorption, but not after viral adsorption, with 50% inhibitory concentration (IC50) values against A/PR/8/34 (H1N1) virus, A/Aichi/2/68 (H3N2) virus and A/Memphis/1/71 (H3N2) virus of 6.35±0.17, 2.84±1.98 and 0.53±0.10 μg/ml, respectively. The plum-juice concentrate exhibited hemagglutination activity toward guinea pig erythrocytes. Its hemagglutination activity was inhibited by the monosaccharide N-acetylneuraminic acid and a sialoglycoprotein (fetuin), but not by the other tested monosaccharides (mannose, galactose, glucose and N-acetylglucosamine), suggesting the presence of a lectin-like molecule(s) in the Japanese plum-juice concentrate. Our findings suggest that the fruit-juice concentrate of Japanese plum may prevent and reduce infection with human influenza A virus, possibly via inhibition of viral hemagglutinin attachment to host cell surfaces by its lectin-like activity.
We cloned a gene responsible for multidrug resistance from chromosomal DNA of Serratia marcescens, and determined the nucleotide sequence. We designated the gene as ssmE. The deduced amino acid sequence of SsmE showed high similarity with the small multidrug resistance (SMR)-type multidrug efflux pumps. Cells of Escherichia coli KAM32, a drug hyper-susceptible mutant, transformed with a plasmid pESM437 carrying the ssmE gene showed elevated minimum inhibitory concentrations of structurally unrelated antimicrobial agents. E. coli KAM32/pESM437 showed elevated energy dependent efflux of ethidium. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis revealed that ssmE was expressed in cells of S. marcescens.
Cinnamaldehyde is a principle compound isolated from Guizhi-Tang (GZT), which is a famous traditional Chinese medical formula used to treat influenza, common cold and other pyretic conditions. Transient receptor potential vanilloid subtype 4 (TRPV4) is expressed in the anterior hypothalamus and may act as thermosensor. The purpose of the present study was to investigate the effects of cinnamaldehyde on the production of prostaglandin E2 (PGE2) and the expression of TRPV4 in mouse cerebral microvascular endothelial cell strain (b.End3). In the research work, the b.End3 cells were cultured in DMEM medium containing interleukin-1β (IL-1β) in the presence or absence of ruthenium red (RR), a kind of known TRPV4 inhibitor, or different concentrations of cinnamaldehyde. The results suggested that IL-1β significantly increase production of PGE2 and cinnamaldehyde evidently decrease IL-1β-induced PGE2 production, while RR showed no inhibitory effect on PGE2 production. Moreover, it was identified that TRPV4 was expressed at the mRNA and protein levels in b.End3 cells. IL-1β could up-regulate the expression of TRPV4, RR and cinnamaldehyde could down-regulate the high expression of mRNA and protein of TRPV4 by IL-1β induced in b.End3 cells. In conclusion, cinnamaldehyde decreased the production of PGE2 and the expression of TRPV4 in b.End3 cells induced by IL-1β.
Byakkokaninjinto (BN) is a Kampo preparation used for the treatment of xerostomia induced by drug, ageing, Sjogren syndrome, etc. The mechanism for BN to induce salivary secretion has not been made clear. In this study, various rat thirst models were prepared using muscarinic receptor blockers, such as 4-diphenylacetoxy-N-methylpiperidine (4-DAMP) and atropine, or adrenoceptor blockers, such as phentolamine and propranolol, in order to investigate the efficiency of BN. When BN was orally administered to the rats in the dose range of 100 to 300 mg/kg, the salivary secretion increased in a dose-dependent manner. The suppression of salivary secretion induced by phentolamine, atropine, and 4-DAMP was recovered by the additional treatment of BN. Interestingly, BN treatment increased the expression of aquaporin 5 in rats, which is known to regulate salivary secretion from the submandibular gland. These results suggested that BN increased the expression of aquaporin 5 through activation of muscarinic M3 receptor and enhanced salivary secretion.
Many studies have suggested that the behavioral and reinforcing effects of cocaine can be mediated by the central dopaminergic systems. It has been shown that repeated injections of cocaine produce an increase in locomotor activity, the expression of the immediate-early gene, c-fos, and the release of dopamine (DA) in the nucleus accumbens (NAc), which is one of the main dopaminergic terminal areas. Several studies have shown that behavioral activation and changes in extracellular dopamine levels in the central nervous system induced by psychomotor stimulants are prevented by ginseng total saponins (GTS). In order to investigate the effects of GTS on the repeated cocaine-induced behavioral and neurochemical alterations, we examined the influence of GTS on the cocaine-induced behavioral sensitization and on c-Fos expression in the brain using immunohistochemistry in rats repeatedly treated with cocaine. We also examined the effect of GTS on cocaine-induced dopamine release in the NAc of freely moving rats repeatedly treated with cocaine using an in vivo microdialysis technique. Pretreatment with GTS (100, 200, 400 mg/kg, i.p.) 30 min before the daily injections of cocaine (15 mg/kg, i.p.) significantly inhibited the repeated cocaine-induced increase in locomotor activity as well as the c-Fos expression in the core and shell in a dose-dependent manner. Also, pretreatment with GTS significantly decreased the repeated cocaine-induced increase in dopamine release in the NAc. Our data demonstrate that the inhibitory effects of GTS on the repeated cocaine-induced behavioral sensitization were closely associated with the reduction of dopamine release and the postsynaptic neuronal activity. The results of the present study suggest that GTS may be effective for inhibiting the behavioral effects of cocaine by possibly modulating the central dopaminergic system. These results also suggest that GTS may prove to be a useful therapeutic agent for cocaine addiction.
IgE-mediated mast cell activation is critical for development of allergic inflammation. We have recently found that selinidin, one of the coumarin derivatives isolated from Angelica keiskei, attenuates mast cell degranulation following engagement of the high-affinity receptor for IgE (FcεRI) with IgE and antigen. In the present study, we investigated the effects of selinidin on intracellular signaling and mast cell activation employing bone marrow-derived mast cells. Here, we report that selinidin attenuates the release of β-hexosaminidase, synthesis of leukotriene C4, and production of tumor necrosis factor-α without affecting IgE-FcεRI binding. Furthermore, biochemical analyses of the FcεRI-mediated signaling pathway demonstrated that selinidin decreases phosphorylation of phospholipase C-γ1, p38 mitogen-activated protein kinase, and IκB-α upon FcεRI stimulation. These results suggest that this compound suppresses IgE-mediated mast cell activation by inhibiting multiple steps of FcεRI-dependent signaling pathways and would be beneficial for the prevention of allergic inflammation.
trans-3,4′-Dimethyl-3-hydroxyflavanone (t-flavanone) is a synthetic compound with hair growth enhancing activity that is effective against male pattern alopecia. t-Flavanone was designed as a derivative of astilbin, the active hair growth enhancing component of Hypericum perforatum extracts. This study was designed to elucidate the mechanism of hair growth enhancement by t-flavanone. We investigated the effects of t-flavanone on transforming growth factor β (TGF-β), a known catagen-inducing factor induced in hair papilla cells by male hormone. When t-flavanone was added to cocultures of human hair papilla cells and human keratinocytes, there was no change in the total level of TGF-β2. However, levels of active TGF-β2 were reduced, suggesting the involvement of t-flavanone in the activation pathway of TGF-β2. In order to investigate the effects of t-flavanone on TGF-β2 activation by human keratinocytes, we evaluated the level of active TGF-β2 converted from the inactive form in t-flavanone-treated human keratinocytes. The amount of active TGF-β2 was reduced compared with controls suggesting that t-flavanone suppresses the TGF-β2 activation cascade in human keratinocytes. We then examined the activity of urokinase-type plasminogen activator (uPA), the rate-limiting enzyme in the TGF-β2 activation cascade, in t-flavanone-treated human keratinocytes. We found that t-flavanone reduces uPA activity on the keratinocyte surface. t-Flavanone is a hair growth enhancing component that has a novel mechanism of action which suppresses TGF-β2 activation, and thereby is expected to have therapeutic effects on other types of alopecia in addition to male pattern alopecia.
It has been reported that pisosterol was active against cancer cells but lacked activity on the development of sea urchin eggs. Recently, it was reported that pisosterol induces differentiation in leukemia cell line. The present study evaluated the in vivo antitumor activity of pisosterol a triterpene isolated from Pisolithus tinctorius. Histopathological and morphological analyses of the tumor and the organs, including liver, spleen and kidney, were performed in order to evaluate toxicological aspects associated with pisosterol treatments. Antitumor activity of pisosterol (50 or 100 mg/m2) was confirmed in mice bearing Sarcoma 180 tumor cells. The tumor growth inhibition ratios were 43.0% and 38.7% for mice treated with pisosterol at 50 and 100 mg/m2, respectively. Histopathological analysis of liver, kidney and spleen was also evaluated. Liver and kidney were the major affected organs by pisosterol, although the observed alterations can be considered reversible.
Madecassoside (MA), one of the principle terpenoids in Centella asiatica, has shown protect effect on isolated rat hearts and isolated cardiomyocytes against reperfusion injury in our previous studies. The aim of this study is to investigate if MA also protected against myocardial ischemia-reperfusion injury in vivo. The ischemia infarction model was established in rats. Left ventricular function was monitored during the ischemia-reperfusion period by a multi-channel recorder. After the ischemia-reperfusion process the infarcted areas were assessed. The levels of lactate dehydrogenase (LDH), creatinephosphokinase (CK), malondialdehyde (MDA), super-oxide dismutase (SOD) and C-reactive protein (CRP) in serum were determined. Cardiomyocytic apoptosis was measured by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining. Pre-treatment with MA (50, 10 mg/kg) attenuated myocardial damage characteristic of decreasing infarct size, decreasing LDH and CK release. Activities of SOD were increased and MDA level increased obviously in control group whereas pretreatment with MA blunted the decrease of SOD activity, markedly reduced the level of MDA and the activity of CRP, and relieved myocardial cell apoptosis. These results suggest that MA has the protective effect on myocardial ischemia-reperfusion injury. This protection ability possibly due to its anti-lipid peroxidation, anti-inflammation and anti-apoptosis function and the enhancement of SOD activity.
In a Japanese cedar pollen-induced allergic conjunctivitis model in guinea pigs, symptoms were aggravated by repeated pollen challenges. In addition, the number of mast cells in the conjunctiva was increased by multiple challenges. The amount of a mast cell mediator, histamine in ophthalmic lavage fluid was also increased by multiple challenges. In the present study, we evaluated the effects of multiple dexamethasone treatments to assess the relationship between the aggravation of symptoms and mast cell hyperplasia. Sensitized guinea pigs were challenged by dropping a pollen suspension onto their eye surface once a week until the 15th challenge. Dexamethasone (10 mg/kg, p.o.) was administered once 3 h before the 15th challenge or 3 h before every 1st—15th challenge. Mast cells in the conjunctival tissue were detected by toluidine blue staining. Histamine was fluorometrically assayed by high-performance liquid chromatography. Serum Cry j 1-specific IgE titer was measured by an enzyme-linked immunosorbent assay. The results indicated that a single treatment with dexamethasone did not affect the 15th challenge-induced symptoms; however, multiple treatments with the corticosteroid suppressed not only conjunctivitis symptoms after every challenge but also the mast cell hyperplasia and the increase in histamine in the lavage fluid. Conversely, the increase in the IgE titer in the serum was not affected by multiple treatments with dexamethasone. In conclusion, increased numbers of mast cells in the conjunctival tissue may be associated with the aggravation of allergic conjunctivitis symptoms.
The administration of L-isoleucine (isoleucine) has been shown to induce hypoglycemia in normal rats. However, it remains to be elucidated whether isoleucine can improve the blood glucose level in glucose-intolerant or diabetic animals. In the present study, oral isoleucine significantly reduced the blood glucose level after an oral glucose challenge in normal mice, as well as in glucose-intolerant mice fed a high-fat diet (HFD) and db/db mice, a model of severe type 2 diabetes. Isoleucine treatment significantly augmented the blood insulin level after an oral glucose load in HFD mice, but not in normal or db/db mice, suggesting that its hypoglycemic activity was attributable to both insulinotropic and non-insulinotropic mechanisms. Chronic supplementation of isoleucine in mice on a high-fat/high-sucrose diet significantly reduced insulin release after an oral glucose challenge without any change in glucose tolerance curve, suggesting that isoleucine might have an insulin-sensitizing effect along with its acute hypoglycemic effect. These results indicate that both acute and chronic treatment with isoleucine is beneficial for glucose metabolism in glucose-intolerant and diabetic animals.
The present study was undertaken to investigate binding activity of synthesized 1,4-dihydropyridine (1,4-DHP) derivatives (Compounds 1—124) to 1,4-DHP calcium channel antagonist receptors in rat brain. Sixteen 1,4-DHP derivatives inhibited specific (+)-[3H]PN 200–110 binding in rat brain in a concentration-dependent manner with IC50 value of 0.43 to 3.49 μM. Scatchard analysis revealed that compounds 54, 69, 85, like nifedipine, caused a significant increase in apparent dissociation constant (Kd) for (+)-[3H]PN 200–110, while compounds 68, 69 and 80 caused a significant decrease in maximal number of bindings sites (Bmax). These data suggest that compounds 68, 69 and 80 exert longer-acting antagonistic effects of 1,4-DHP receptors than compounds 54, 69 and 85. The structure–activity relationship study has revealed that 1) ester groups in 3- and 5-positions are the most effective, 2) the aryl group in the 4-position of 1,4-DHP ring is the basic requirement for optimal activity, 3) position and type of electron-withdrawing groups on phenyl group at position 4 would affect the receptor-binding activity. Furthermore, compound 58 exerted α1 receptor binding activity, being 1.6 times greater than 1,4-DHP receptors. Compounds 81, 84, 91, 94, 106, 108 and 109 showed significant binding of ATP-sensitive potassium (KATP) channel, and the binding activities of compounds 81, 84, 108 and 109 were 1.6—3.8 times greater than the binding activity for 1,4-DHP receptors. Compounds 91 and 106 had similar binding activity for KATP channel and 1,4-DHP receptors. In conclusion, the present study has shown that novel 1,4-DHP derivatives exert relatively high binding affinity to 1,4-DHP receptors and has revealed new aspect of structure–activity relationships of 1,4-DHP derivatives, especially hexahydroquinoline derivatives.
A line of evidence has shown that ginsenoside Rg3 (Rg3) could be one of bioactive ligands in brain Na+ channel regulations. Rg3 exists as stereoisomer of 20(R)- or 20(S)-form. Rg3 consists of three different parts; steroid- like backbone structure, carbohydrate portion, and aliphatic side chain [–CH2CH2CH=C(CH3)2], which is coupled to the carbon-20 of backbone structure. In the previous report, we demonstrated that 20(S)- but not 20(R)-Rg3 and carbohydrate portion of Rg3 play important roles in rat brain NaV1.2 channel regulations. However, little is known about the role of aliphatic side chain coupled to the carbon-20 in brain Na+ channel regulations. In the present study, we prepared Rg3 derivatives by modifying the aliphatic side chain of Rg3, remaining with backbone structure and carbohydrate portion intact, and examined the effects of Rg3 derivatives on Na+ channel activity. We found that reduction of double bond in aliphatic side chain of Rg3 exhibited agonistic actions in Na+ channel current inhibitions by shifting concentration–response curve to leftward by three-fold, whereas deletion, hydroxylation, or oxygenation of aliphatic side chain caused an attenuation or loss of Na+ channel current inhibitions. These results provide evidences that the aliphatic side chain of Rg3 is also involved in Na+ channel regulations and further show a possibility that the aliphatic side chain of Rg3 could be the target of chemical modifications for abolishment or potentiation of Rg3 actions in Na+ channel regulations.
Using a mouse model of advanced skin cancer which has mixed nociceptive-neuropathic pain, we evaluated the analgesic effects of morphine and analgesic adjuvants. Morphine hydrochloride (10—30 mg/kg, oral) and mexiletine hydrochloride (10—30 mg/kg, intraperitoneal) dose-dependently inhibited thermal hyperalgesia. Baclofen (10 mg/kg, subcutaneous) suppressed thermal hyperalgesia, without effects at lower doses of 1 and 5 mg/kg. Ketamine hydrochloride (50 mg/kg, oral) was without effect. Analgesic tolerance was observed after 6th administration of morphine, and it was not developed until at least 7th administration of mexiletine and baclofen. This mouse model of skin cancer may be useful for the pharmacological evaluation of the effects of opioids and analgesic adjuvants on mixed nociceptive-neuropathic pain of advanced cancer.
In the course of isolating preventive agents from sepsis based on the in vivo assay model from the EtOAc extract of the roots of Saururus chinensis, twelve lignans, sarisan (1), erythro-austrobailignan-6 (2), meso-dihydroguaiaretic acid (3), saucerneol B (4), manassantin B (5), manassantin A (6), rel-(8R,8′R)-dimethyl-(7S,7′R)-bis(3,4-methylenedioxyphenyl)tetrahydro-furan (7), (+)-saururinone (8), sauchinone (9), sauchinone B (10), nectandrin B (11) and machilin D (12), were isolated. Compounds 9 and 10, at a dose of 10 mg/kg, increased survival rates to 80% from 20% for the control experiment, and decreased the plasma levels of tumor necrosis factor-α (TNF-α) and alanine aminotransferase (ALT) activity in mice administered LPS/D-GalN.
Chronic marginal periodontitis is a destructive inflammatory disease caused by an imbalance between bacterial virulence and host defense ability, resulting in eventual tooth exfoliation. Porphyromonas gingivalis, a major periodontal pathogen, triggers a series of cellular inflammatory responses including the production of prostaglandin E2 (PGE2), which causes periodontal destruction; thus, anti-inflammatory reagents are considered beneficial for periodontal therapy. In the present study, we examined whether hop- and apple-derived polyphenols (HBP and ACT, respectively) inhibit PGE2 production by human gingival epithelial (HGE) cells stimulated with P. gingivalis components. HGE cells were stimulated with P. gingivalis membrane vesicles, and the effects of HBP, ACT and epigallocatechin gallate (EGCg) on PGE2 production by HGE cells were evaluated using an enzyme-linked immunosorbent assay. HBP and EGCg significantly inhibited PGE2 production, whereas ACT did not. By further fractionation steps of HBP to identify the effective components, 3 components of HBP, 2-[(2-methylpropanoyl)-phloroglucinol]1-O-β-D-glucopyranoside (MPPG), quercetin 3-O-β-D-glucopyranoside (isoquercitrin), and kaempferol 3-O-β-glucopyranoside (astragalin), were found to be elements which significantly inhibited cellular PGE2 production. These results suggest that HBP is a potent inhibitor of cellular PGE2 production induced by P. gingivalis, and HBP may be useful for the prevention and attenuation of periodontitis.
Inducible heme oxygenase (HO)-1 is known to play a major role in the pathogenesis of several diseases, and it protects cells against oxidant-mediated injury. The bioassay-guided fractionation of the EtOH extract of the flowered fruit-spike of Prunella vulgaris L. (Labiatae) yielded two ursane-type triterpenes, 3β,23-dihydroxyurs-12-en-28-oic acid (23-hydroxyursolic acid) (1) and 3β-hydroxyurs-12-en-28-oic acid (ursolic acid) (2). Western blotting demonstrated that treatment with compound 1 increased the expression of HO-1 in a dose-dependent manner in human liver-derived HepG2 cells. Investigation of structure-related HO-1 inducing activity suggested that the hydroxyl group at the C-23 position in the ursane skeleton is important for this activity.
Many phytochemicals found in the diet may prevent colon carcinogenesis by affecting biochemical processes in the colonic mucosa. Inflammation and subsequent elevation of the enzyme cyclooxygenase-2 (COX-2) are two such factors involved in the development of colon cancer, and inhibition of these processes could be important targets for chemoprevention. We have previously shown COX-2 inhibitory activity locally in the colon; e.g. in human fecal water from a group of vegetarians. In this study we focus on 2-pentanone, a frequently occurring compound in common foods such as banana and carrot. The aim was to study the inhibitory effects on prostaglandin production and COX-2 protein expression in tumour necrosis factor-α stimulated colon cancer cells (HT29) by radioimmunoassay and Western blotting. 2-Pentanone inhibited both prostaglandin production and COX-2 protein expression in human colon cancer cells. A concentration of 400 μmol/l 2-pentanone inhibited the prostaglandin production by 56.9±12.9% which is in the same range as the reference compound NS398 (59.8±7.6%). The two highest concentrations of 2-pentanone were further analyzed by Western blot, and 400 μmol/l and 200 μmol/l 2-pentanone resulted in a 53.3±9.6% and ±27.1% reduction of the COX-2 protein levels respectively. Further studies on flavouring compounds, for example 2-pentanone, as colon cancer chemopreventives would be very valuable, and such results may contribute to future dietary recommendations.
The aim of the study was to investigate the anti-trypanocidal activities of natural chromene and chromene derivatives. Five chromenes were isolated from Piper gaudichaudianum and P. aduncum, and a further seven derivatives were prepared using standard reduction, methylation and acetylation procedures. These compounds were assayed in vitro against epimastigote forms of Trypanosoma cruzi, the causative agent of Chagas disease. The results showed that the most of the compounds, especially those possessing electron-donating groups as substituents on the aromatic ring, showed potent trypanocidal activity. The most active compound, [(2S)-methyl-2-methyl-8-(3″-methylbut-2″-enyl)-2-(4′-methylpent-3′-enyl)-2H-chromene-6-carboxylate], was almost four times more potent than benznidazole (the positive control) and showed an IC50 of 2.82 μM. The results reveal that chromenes exhibit significant anti-trypanocidal activities and indicate that this class of natural product should be considered further in the development of new and more potent drugs for use in the treatment of Chagas disease.
The effect of iontophoresis and switching iontophoresis on the skin accumulation of drugs was investigated. An acrylic diffusion cell mounted with electrode cells (bore: 2.2 cm) with circular platinum electrodes (diameter: 2.0 cm) was used for the skin accumulation study. The skin accumulation of fluorescein after non-switching and switching iontophoresis was macroscopically compared with that achieved by passive diffusion (control). Intense fluorescence was observed after the application of non-switching and switching iontophoresis. Furthermore, fluorescence was observed just under the electrode cell and hardly spread in the skin beyond the area of the electrode cell. The skin accumulation of ketoprofen after non-switching and switching iontophoresis was also compared with control data. Although non-switching iontophoresis showed the highest amount of ketoprofen accumulated in skin, skin irritation was observed. Among the various switching intervals, switching iontophoresis using 10-min intervals achieved the highest value, and there was no skin irritation. Furthermore, the amount of ketoprofen accumulated was maintained after switching iontophoresis at 10-min intervals up to 180 min. Since the amount of ketoprofen in skin after switching iontophoresis was greater than that after intermittent iontophoresis, switching iontophoresis should increase the amount of ketoprofen due to enhancement of skin penetration by skin hydration. These findings suggest that switching iontophoresis using an optimal switching interval can prevent skin irritation and enhance drug accumulation in the skin.
In the case of cancer chemotherapy for hepatocellular carcinoma, anthracycline anticancer agents such as epirubicin are widely used, and have typically been given by intrahepatic arterial (i.a.) infusion to increase treatment efficacy and to reduce systemic toxicity. The anthracyclines are eliminated primarily by the liver, and the use of these drugs in patients with hepatic failure can be difficult. In this study, we investigated the effect of acute hepatic failure on the pharmacokinetics of epirubicin after i.a. injection in rats. Experimental acute hepatic failure was induced by carbon tetrachloride-treatment. Epirubicin was injected into the hepatic artery or the saphenous vein of the rats at a dose of 2 mg/kg. After both intravenous (i.v.) and i.a. injection, the serum concentration and the AUC0—24 of epirubicin in hepatic failure rats were significantly higher than the values in control rats. The AUC0—24 ratio of hepatic failure (i.a.) to control (i.a.) was higher than the ratio of hepatic failure (i.v.) to control (i.v.). These results suggest that the influence of hepatic failure on serum epirubicin concentration is larger with the i.a. route than with the i.v. route. The liver concentration of epirubicin after i.a. administration in hepatic failure rats was significantly lower than that in control rats. This result suggests that the effect of the liver-selective drug targeting after i.a. injection in hepatic failure rats is lower than in normal rats. Therefore, we should be careful when administering epirubicin by the i.a. route in patients with acute hepatic failure.