The interaction of host genetic factors and <Emphasis Type="Italic">Helicobacter</Emphasis> <Emphasis Type="Italic">pylori</Emphasis> infection

Helicobacter pylori plays an important role in the development of atrophic gastritis that represents the most recognized pathway in multistep gastric carcinogenesis. Recent studies suggest that a combination of host genetic factors, bacterial virulence factors, and environmental and lifestyle factors determine the severity of gastric damage and the eventual clinical outcome of Helicobacter pylori infection. As to bacterial virulence factors, a high proportion of Japanese strains are cagA⁺vacAs1. The CagA protein is injected from attached Helicobacter pylori into gastric epithelial cells and the CagA-SHP-2 interactions elicit cellular changes that increase the risk of carcinogenesis. Host cytokine gene polymorphisms and a frequent single nucleotide polymorphism in the PTPN11 gene that encodes SHP-2 may associate with gastric atrophy among Helicobacter pylori-infected subjects. Prevention of gastric cancer requires the development of better screening strategies for determining eradication candidates and further improvement of treatments of Helicobacter pylori infection. Received 6 August 2006; accepted 21 August 2006     

Components of convolvulin from <Emphasis Type="Italic">Quamoclit</Emphasis> × <Emphasis Type="Italic">multifida</Emphasis>

Alkaline hydrolysis of the ether-insoluble resin glycoside (convolvulin) fraction of the seeds of Quamoclit × multifida (syn. Q. sloteri House, Convolvulaceae), a hybrid between Q. pennat and Q. coccinea, gave three new glycosidic acids (maltifidinic acids C, D, and E) along with three known glycosidic acids (quamoclinic acids B, C, and D) and four organic acids (2S-methylbutyric, tiglic, 2R,3R-nilic, and 7S-hydroxydecanoic acids). The structures of the new glycosidic acids were characterized on the basis of spectroscopic data as well as chemical evidence.     

β-secretase (BACE1) inhibitors from <Emphasis Type="Italic">Perilla frutescens</Emphasis> var. <Emphasis Type="Italic">acuta</Emphasis>

In the course of screening for anti-dementia agents from natural products, two β-secretase (BACE1) inhibitors were isolated from the methanolic extract of Perilla frutescens var. acuta and identified as luteolin (1) and rosmarinic acid (2) with IC₅₀ values of 5.0×10⁻⁷ M and 2.1×10⁻⁵ M, respectively. They inhibited BACE1 in a non-competitive manner with a substrate in Dixon plots, suggesting that they might bind to either β-secretase subsite or to another regulatory site. Ki values of 1 and 2 were 6.2×10⁻⁵ M and 3.9×10⁻⁵ M, respectively. They were less inhibitory against other enzymes such as α-secretase (TACE), acetylcholine esterase (AchE), chymotrypsin, and elastase, indicating that they were relatively specific inhibitors of BACE1.     

<Emphasis Type="Italic">Buddlejol</Emphasis>, a new α-chymotrypsin inhibitor from <Emphasis Type="Italic">Buddleja asiatica</Emphasis>

Buddlejol (1), a new sterol, has been isolated from the ethyl acetate soluble fraction of the antispasmodic plant Buddleja asiatica along with stigmasterol (2), lignoceric acid (3), taraxerol (4) and α-amyrin (5), respectively. The structure of Buddlejol (1) was established as (24S)-stigmast-5,22-diene-7β-ethoxy-3β-ol by spectral analysis and comparison with closely related structures. Buddlejol revealed to be a competitive inhibitor of chymotrypsin with the Ki value of 10.60 µM as indicated by Lineweaver–Burk and Dixon plots and their re-plots against its chymotrypsin inhibition assay, while the other compounds showed less inhibitory potential. The bioassay-guided isolation was stimulated by the preliminary cytotoxic screening of various fractions of B. asiatica.     

Poly(ε-caprolactone)-<Emphasis Type="Italic">Block</Emphasis>-poly(ethyl Ethylene Phosphate) Micelles for Brain-Targeting Drug Delivery: <Emphasis Type="Italic">In Vitro</Emphasis> and <Emphasis Type="Italic">In Vivo</Emphasis> Valuation

Purpose  

The purpose of this work was to investigate the potential of poly(ε-caprolactone)-block-poly(ethyl ethylene phosphate) (PCL-PEEP) micelles for brain-targeting drug delivery.     

Toxicity of abamectin to the terrestrial isopod <Emphasis Type="Italic">Porcellio</Emphasis> <Emphasis Type="Italic">scaber</Emphasis> (Isopoda,Crustacea)

To determine effects of the antiparasitic veterinary drug abamectin on the isopod Porcellio scaber, animals were exposed for 21 days to Lufa 2.2 soil spiked at concentrations of 3–300 mg/kg dry soil. After exposure, abamectin residues in the isopods were analysed using a novel analytical method. Toxicity was evaluated on different levels of biological organisation: biochemical, cellular and the individual organism. Measurements included glutathione S-transferase (GST) activity and stability of cell membranes in the digestive gland, animal mass gain or loss, food consumption, behaviour and mortality. LC50 for the effect of abamectin on survival of P. scaber was 71 mg/kg dry soil. The most obvious sublethal effects were reduced food consumption and decreased body mass (NOEC 3 mg/kg dry soil). Additionally, loss of digging activity and reduced GST activity (NOEC 30 mg/kg dry soil) and cell membrane destabilization (NOEC 10 mg/kg dry soil) were recorded. Abamectin only slightly accumulated in the isopods, with bioaccumulation factors always being <0.1. Based on these results and current information on environmental levels of abamectin, it is not likely that isopods will be affected by abamectin, but further studies with exposure through faeces are recommended.     

Synthesis and pharmacological properties of alkylammonium salts of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-malonyl-<Emphasis Type="Italic">bis</Emphasis>-<Emphasis Type="Italic">p</Emphasis>-aminobenzoic acid

A series of ammonium salts of N,N′-malonyl-bis-p-aminobenzoic acid with some alkylamines have been obtained. It is established that these compounds possess hypotensive, antiarrhythmic, and anticoagulative activities depending on the structure of the alkylamine constituents.     

Structure–activity relationship study of secondary metabolites from <Emphasis Type="Italic">Mesua beccariana</Emphasis>, <Emphasis Type="Italic">Mesua ferrea</Emphasis> and <Emphasis Type="Italic">Mesua congestiflora</Emphasis> for anti-cholinesterase activity

Our search for potential anti-acetylcholinesterase (AChE) inhibitors for treatment of Alzheimer’s disease has led to the discovery of two bioactive compounds, α-mangostin (11) and congestiflorone acetate (13). This discovery was achieved from a preliminary screening of the anti-AChE activity on the extracts of three Mesua species namely M. ferrea, M. beccariana and M. congestiflora using Ellman’s method. The pure metabolites, 1–12 which were isolated from the Mesua species, along with a synthetic derivative, compound 13 were then evaluated for their activities in order to identify the compounds that correspond to the enzyme inhibitory activities. Compounds 11 and 13 were found to give significant anti-AChE activities with IC₅₀ values of 17.51 and 20.25 µM.     

A glycerol α-<Emphasis Type="SmallCaps">d</Emphasis>-glucuronide and a megastigmane glycoside from the leaves of <Emphasis Type="Italic">Guettarda</Emphasis><Emphasis Type="Italic">speciosa</Emphasis> L.

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Guettarda speciosa L., two new compounds (1, 2) were isolated together with six known compounds. Spectroscopic analysis of 1 and 2 established their structures to be derivatives of a glycerol α-glucuronide and a megastigmane glycoside, respectively. HPLC analysis of the hydrolyzate of 1 confirmed the presence of d-glucuronic acid in the structure, and the modified Mosher’s method established the absolute structure of 2.     

<Emphasis Type="Italic">Helicobacter pylori</Emphasis>-induced <Emphasis Type="Italic">gastric mucosal</Emphasis> TGF-α ectodomain shedding and EGFR transactivation involves Rac1/p38 MAPK-dependent TACE activation

Infection of gastric mucosa by H. pylori triggers a pattern of inflammatory responses characterized by the rise in proinflammatory cytokine production, up-regulation in mitogen-activated protein kinase (MAPK) cascade, and the induction in epidermal growth factor receptor (EGFR) activation. In this study, we report on the role of MAPK/p38 and Rac1 in the regulation of H. pylori LPS-induced TGF-α ectodomain shedding and EGFR transactivation. We show that stimulation of gastric mucosal cells with the LPS, reflected in p38 phosphorylation, guanine nucleotide exchange factor Dock180 activation and the rise in Rac1-GTP level, is accompanied by the activation of membrane-associated metalloprotease, (TACE) also known as ADAM17, responsible for soluble TGF-α release. Further, we reveal that the LPS-induced TGF-α shedding and EGFR transactivation involves the TACE activation through phosphorylation by p38 that requires Rac1 participation. Moreover, we demonstrate that up-regulation in H. pylori LPS-elicited Rac1-GTP membrane translocation plays a pivotal role in recruitment of the activated p38 to the membrane for TACE activation through phosphorylation on Thr⁷³⁵. Taken together, our findings provide strong evidence as to the essential function of Rac1 in TACE activation, TGF-α ectodomain shedding, and the EGFR transactivation.     

Standardization of extract mixture of <Emphasis Type="Italic">Chaenomeles sinensis</Emphasis> and <Emphasis Type="Italic">Phyllostachys bambusoides</Emphasis> for anti-obesity by HPLC–UV

JM-101 is a developed functional food formula using water extract of Chaenomeles sinensis and Phyllostachys bambusoides for anti-obesity. Standardization and quality control of herb mixture is more difficult than those of single herb. Additionally, the estimation of mixing ratio is an essential requirement for standardization. This study aimed to develop an efficient analytical method for the standardization of JM-101 based on C. sinensis and P. bambusoides. Protocatechuic acid and p-coumaric acid were selected as marker compounds of JM-101. A mixture of the two medicinal materials (1:1 w/w) was extracted by water and then liquid–liquid extracted (LLE) by ethyl acetate. The supernatant was evaporated to dryness and dissolved in methanol for analysis. The extraction time, material-to-water ratio and ethyl acetate-to-water ratio were optimized by multi-response optimization based on response surface methodology (RSM). The established methods were validated in terms of linearity, precision, accuracy, repeatability, stability and recovery. The novel method based on LLE and RSM provides a sensitive, accurate analysis and excellent extraction efficiency of marker compounds in JM-101, without interruption of other compounds in JM-101. In conclusion, the developed simultaneous analytical method contributes to the standardization of two materials (C. sinensis and P. bambusoides) and JM-101.     

Imiquimod Induces Apoptosis in Human Endometrial Cancer Cells <Emphasis Type="Italic">In vitro</Emphasis> and Prevents Tumor Progression <Emphasis Type="Italic">In vivo</Emphasis>

Purpose

The increasing incidence of endometrial cancer (EC), in younger age at diagnosis, calls for new tissue-sparing treatment options. This work aims to evaluate the potential of imiquimod (IQ) in the treatment of low-grade EC.

Methods

Effects of IQ on the viabilities of Ishikawa and HEC-1A cells were evaluated using MTT assay. The ability of IQ to induce apoptosis was evaluated by testing changes in caspase 3/7 levels and expression of cleaved caspase-3, using luminescence assay and western blot. Apoptosis was confirmed by flow cytometry and the expression of cleaved PARP. Western blot was used to evaluate the effect of IQ on expression levels of Bcl-2, Bcl-xL, and BAX. Finally, the in vivo efficacy of IQ was tested in an EC mouse model.

Results

There was a decrease in EC cell viability following IQ treatment as well as increased caspase 3/7 activities, cleaved caspase-3 expression, and Annexin-V/ 7AAD positive cell population. Western blot results showed the ability of IQ in cleaving PARP, decreasing Bcl-2 and Bcl-xL expressions, but not affecting BAX expression. In vivo study demonstrated IQ’s ability to inhibit EC tumor growth and progression without significant toxicity.

Conclusions

IQ induces apoptosis in low-grade EC cells in vitro, probably through its direct effect on Bcl-2 family protein expression. In, vivo, IQ attenuates EC tumor growth and progression, without an obvious toxicity. Our study provides the first building block for the potential role of IQ in the non-surgical management of low-grades EC and encouraging further investigations.

     

Synthesis and anticonvulsant evaluation of<Emphasis Type="Italic">N-Cbz</Emphasis>-α-amino-<Emphasis Type="Italic">N</Emphasis>-alkoxysuccinimides

In previous studies for the development of new anticonvulsants, we found that N-Cbz-alpha-amino-N-alkylsuccinimides exhibited significant anticonvulsant activities in the Maximal electroshock seizure (MES) and Pentylenetetrazole induced seizure (PTZ) tests, and also their anticonvulsant activities were dependent on the N-alkyl substituents existent in their structures. Based on these estimations, N-Cbz-alpha-amino-N-hydroxysuccinimide and various N-Cbz-alpha-amino-N-alkoxysuccinimides were prepared in order to develop more active anticonvulsants and to examine the effects of N-hydoxy or N-alkoxy groups on their anticonvulsant activities. The (R)- or (S)-N-Cbz-alpha-amino-N-hydroxysuccinimide and N-Cbz-alpha-amino-N-alkoxysuccinimides were prepared from the corresponding (R)- or (S)-N-Cbz-aspartic acid through the known synthetic procedures. Their anticonvulsant activities in the MES and PTZ test were evaluated. All of these compounds except 3a showed significant anticonvulsant activities against the PTZ test, but these compounds were not active in the MES test. The most active compound in the PTZ test was (R)-N-Cbz-alpha-amino-N-benzyloxysuccinimide (ED50=62.5 mg/kg). In addition, the anticonvulsant activities of these compounds were dependent on their N-substited groups. The order of anticonvulsant activity against the PTZ test, as judged from the ED50 values for (R) series was N-benzyloxy > N-hydroxy > N-isopropoxy > N-methoxy > N-ethoxy; for the (S) series N-ethoxy > N-benzyloxy > N-methoxy > N-isopropoxy.     

Side Effects of Interferon-<Emphasis Type="Italic">α</Emphasis> Therapy

Aim

Interferon-α (IFN-α) has been extensively explored for its efficacy in various disease conditions and is currently used as a standard treatment in several of these. Its use is accompanied by a wide variety of possible side effects. These side-effects may hamper reaching and maintaining the dose needed for maximal therapeutic effect while their occurrence can outweigh clinical benefit of IFN-α treatment. This review addresses the toxicity profile of IFN-α, the presumed pathophysiology of the different side effects and the strategies to handle these.

Methods

Computerized searches were used and cross-references of articles and books were checked.

Results

Adverse effects due to IFN-α have been described in almost every organ system. Many side-effects are clearly dose-dependent. Taken together, occurrence of flu-like symptoms, hematological toxicity, elevated transaminases, nausea, fatigue, and psychiatric sequelae are the most frequently encountered. Although insight in the mechanisms accounting for IFN-α-related toxicities has improved in recent years, much remains to be elucidated. Guidelines on the management of these untoward sequelae are mostly based on clinical experience, while many side-effects can only be adequately handled by dose adjustment or cessation of treatment.

Conclusion

Further research on the mechanisms underlying both therapeutic effects and adverse events is warranted. Hopefully, this will lead to better identification of those patients who are likely to benefit from treatment without experiencing severe toxicities.

     

Quantification of toxins in a Cry1Ac + CpTI cotton cultivar and its potential effects on the honey bee <Emphasis Type="Italic">Apis mellifera</Emphasis> L.

Transgenic Cry1Ac + CpTI cotton (CCRI41) is increasingly planted throughout China. However, negative effects of this cultivar on the honey bee Apis mellifera L., the most important pollinator for cultivated ecosystem, remained poorly investigated. The objective of our study was to evaluate the potential side effects of transgenic Cry1Ac + CpTI pollen from cotton on young adult honey bees A. mellifera L. Two points emphasized the significance of our study: (1) A higher expression level of insecticidal protein Cry1Ac in pollen tissues was detected (when compared with previous reports). In particular, Cry1Ac protein was detected at 300 ± 4.52 ng g⁻¹ [part per billion (ppb)] in pollen collected in July, (2) Effects on chronic mortality and feeding behaviour in honey bees were evaluated using a no-choice dietary feeding protocol with treated pollen, which guarantee the highest exposure level to bees potentially occurring in natural conditions (worst case scenario). Tests were also conducted using imidacloprid-treated pollen at a concentration of 48 ppb as positive control for sublethal effect on feeding behaviour. Our results suggested that Cry1Ac + CpTI pollen carried no lethal risk for honey bees. However, during a 7-day oral exposure to the various treatments (transgenic, imidacloprid-treated and control), honey bee feeding behaviour was disturbed and bees consumed significantly less CCRI41 cotton pollen than in the control group in which bees were exposed to conventional cotton pollen. It may indicate an antifeedant effect of CCRI41 pollen on honey bees and thus bees may be at risk because of large areas are planted with transgenic Bt cotton in China. This is the first report suggesting a potential sublethal effect of CCRI41 cotton pollen on honey bees. The implications of the results are discussed in terms of risk assessment for bees as well as for directions of future work involving risk assessment of CCRI41 cotton.     

Antioxidant constituents in the dayflower (<Emphasis Type="Italic">Commelina communis</Emphasis> L.) and their α-glucosidase-inhibitory activity

The dayflower, Commelina communis L., contains 1-deoxynojirimycin (DNJ) and (2R,3R,4R,5R)2,5-bis(hydroxymethyl)-3,4-dihydroxypyrrolidine (DMDP), potent α-glucosidase inhibitors. The extracts and powder of this herb are important food materials for prophylaxis against type 2 diabetes. Eleven flavonoid glycosides as antioxidants, isoquercitrin, isorhamnetin-3-O-rutinoside, isorhamnetin-3-O-β-d-glucoside, glucoluteolin, chrysoriol-7-O-β-d-glucoside, orientin, vitexin, isoorientin, isovitexin, swertisin, and flavocommelin, were identified from the aerial parts of C. communis. Their antioxidant activities were measured using in vitro assays employing the 1,1-diphenyl-2-picrylhydrazyl radical- and superoxide radical-scavenging assays. The results showed that glucoluteolin, orientin, isoorientin, and isoquercitrin are the predominant antioxidants in this herb. Moreover, isoquercitrin, isorhamnetine-3-O-rutinoside, vitexin, and swertisin inhibited the activity of α-glucosidase from rat intestine.     

Synthesis of novel <Emphasis Type="Italic">N</Emphasis>-acyl-<Emphasis Type="Italic">β</Emphasis>-<Emphasis Type="SmallCaps">d</Emphasis>-glucopyranosylamines and ureas as potential lead cytostatic agents

Novel classes of acetylated and fully deprotected N-acyl-β-d-glucopyranosylamines and ureas have been synthesized and biologically evaluated. Acylation of the per-O-acetylated β-d-glucopyranosylurea (5), easily prepared via its corresponding phosphinimine derivative, by zinc chloride catalyzed reaction of the corresponding acyl chlorides RCOCl (a–f) gave the protected N-acyl-β-d-glucopyranosylureas (6a–f), in acceptable-to-moderate yields. Subsequent deacetylation of analogues 6a–f under Zemplén conditions afforded the fully deprotected derivatives 7a,b,d,e,f, while the desired urea 7c was formed after treatment of 6c with dibutyltin oxide. All protected and unprotected compounds were examined for their cytotoxic activity in different L1210, CEM and HeLa tumor cell lines and were also evaluated against a broad panel of DΝΑ and RNA viruses. Derivative 7c exhibited cytostatic activity against the three evaluated tumor cell lines (IC₅₀ 9–24 μΜ) and might be the basis for the synthesis of structure-related derivatives with improved cytostatic potential. Only analogue 6f weakly but significantly inhibited the replication of parainfluenza-3 virus, Sindbis virus and Coxsackie virus B4 in cell cultures at concentrations of 45–58 μM.     

Propensity to metal accumulation and oxidative stress responses of two benthic species (<Emphasis Type="Italic">Cerastoderma edule</Emphasis> and <Emphasis Type="Italic">Nephtys hombergii</Emphasis>): are tolerance processes limiting their responsiveness?

The chronic exposure of benthic organisms to metals in sediments can lead to the development of tolerance mechanisms, thus diminishing their responsiveness. This study aims to evaluate the accumulation profiles of V, Cr, Co, Ni, As, Cd, Pb and Hg and antioxidant system responses of two benthic organisms (Cerastoderma edule, Bivalvia; Nephtys hombergii, Polychaeta). This approach will provide clarifications about the ability of each species to signalise metal contamination. Organisms of both species were collected at the Tagus estuary, in two sites with distinct contamination degrees (ALC, slightly contaminated; BAR, highly contaminated). Accordingly, C. edule accumulated higher concentrations of As, Pb and Hg at BAR compared to ALC. However, antioxidant responses of C. edule were almost unaltered at BAR and no peroxidative damage occurred, suggesting adjustment mechanisms to the presence of metals. In contrast, N. hombergii showed a minor propensity to metal accumulation, only signalising spatial differences for As and Pb and accumulating lower concentrations of metals than C. edule. The differences in metal accumulation observed between species might be due to their distinctive foraging behaviour and/or the ability of N. hombergii to minimise the metal uptake. Despite that, the accumulation of As and Pb was on the basis of the polychaete antioxidant defences inhibition at BAR, including CAT, SOD, GR and GPx. The integrated biomarker response index (IBRv2) confirmed that N. hombergii was more affected by metal exposure than C. edule. In the light of current findings, in field-based studies, the information of C. edule as a bioindicator should be complemented by that provided by another benthic species, since tolerance mechanisms to metals can hinder a correct diagnosis of sediment contamination and of the system’s health. Overall, the present study contributed to improve the lack of fundamental knowledge of two widespread and common estuarine species, providing insights of the metal accumulation profiles under a scenario of chronic contamination. Finally, this work provided useful information that can be applied in the interpretation of future environmental monitoring studies.