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PubMed2006

Inhibition of nitric oxide biosynthesis by anthocyanin fraction of blackberry extract.

Anthocyanins are natural colorant belonging to the flavonoid family, widely distributed among flowers, fruits, and vegetables. Some flavonoids have been found to possess anticarcinogenic, cytotoxic, cytostatic, antioxidant, and anti-inflammatory properties. Since increased nitric oxide (NO) plays a role in inflammation, we have investigated whether the pharmacological activity of the anthocyanin fraction of a blackberry extract (cyanidin-3-O-glucoside representing about 88% of the total anthocyanin content) was due to the suppression of NO synthesis. The markedly increased production of nitrites by stimulation of J774 cells with lipopolysaccharide (LPS) for 24 h was concentration-dependently inhibited by the anthocyanin fraction (11, 22, 45, and 90 microg/ml) of the extract. Moreover, this inhibition was dependent on a dual mechanism, since the extract attenuated iNOS protein expression and decreased the iNOS activity in lungs from LPS-stimulated rats. Inhibition of iNOS protein expression appeared to be at the transcriptional level, since the extract and similarly cyanidin-3-O-glucoside (10, 20, 40, and 80 microg/ml, amounts corresponding to the concentrations present in the extract) decreased LPS-induced NF-kappaB activation, through inhibition of IkappaBalpha degradation, and reduced ERK-1/2 phosphorylation in a concentration-dependent manner. In conclusion, our study demonstrates that at least some part of the anti-inflammatory activity of blackberry extract is due to the suppression of NO production by cyanidin-3-O-glucoside, which is the main anthocyanin present in the extract. The mechanism of this inhibition seems to be due to an action on the expression/activity of the enzyme. In particular, the protein expression was inhibited through the attenuation of NF-kappaB and/or MAPK activation.

Animals↗
PubMedDate not supplied

Induction of apoptosis by the aqueous extract of Rubus coreanum in HT-29 human colon cancer cells.

OBJECTIVES: The incompletely ripened fruit of Rubus coreanum (IRFRC) has been used in traditional herbal medicine to manage various diseases. To explore the possibility that IRFRC has chemopreventive effects, we examined whether or not extracts of IRFRC inhibits HT-29 cell growth and explored the mechanism for this effect. METHODS: We cultured HT-29 cells in the presence of the aqueous or ethanol extract of IRFRC. DNA synthesis was estimated by 5-bromo-2'-deoxyuridine incorporation. We measured apoptosis using a DNA fragmentation assay and Annexin V staining. We used western blot analyses to determine the cleavage of caspases and poly (adenosine diphosphate-ribose) polymerase. RESULTS: Aqueous extract of IRFRC substantially inhibited viable HT-29 cell number in a dose-dependent manner, whereas ethanol extract had only a minimal effect. Aqueous extract inhibited DNA synthesis and induced apoptosis of HT-29 cells in a dose-dependent manner. Aqueous extract induced cleavage of caspase-3, -7, and -9 and induced the activity of caspase-3 and cleavage of poly (adenosine diphosphate-ribose) polymerase. CONCLUSIONS: We have shown that aqueous extract of IRFRC inhibits cell proliferation and stimulates apoptosis in HT-29 cells, and that this may be mediated by its ability to activate the caspase-3 pathway. It remains to be determined whether the aqueous extract of IRFRC has chemopreventive activities in animal models.

Antineoplastic Agents, Phytogenic↗
PubMed2006

Antiproliferative activity is predominantly associated with ellagitannins in raspberry extracts.

Raspberry extracts enriched in polyphenols, but devoid of organic acids, sugars and vitamin C, were prepared by sorption to C18 solid phase extraction matrices and tested for their ability to inhibit the proliferation of human cervical cancer (HeLa) cells in vitro. The raspberry extract reduced proliferation in a dose-dependent manner whether this was judged by cell number or measurements of cell viability. However, measurements based on cell viability were more accurate and gave an EC(50) value of 17.5 microg/ml gallic acid equivalents (GAE) at day 4 of culture. Raspberry extracts were fractionated by sorption to Sephadex LH-20 into an unbound fraction, which was obviously enriched in anthocyanins, and a bound fraction. The unbound anthocyanin-enriched fraction was much less effective in reducing proliferation then the original extract and gave an EC(50) value estimated at 67 microg/ml. The LH-20 bound fraction was more effective than the original raspberry extract (EC(50)=13 microg/ml) suggesting that the main anti-proliferative agents were retained in the bound fraction. Analysis of the original extract, the unbound and the LH20 bound fractions by LC-MS confirmed that the unbound fraction was enriched in anthocyanins and the bound fraction primarily contained ellagitannins. The ellagitannin-rich bound fraction had the highest antioxidant capacity as measured by the ferric reducing antioxidant potential (FRAP) assay. The mechanism by which the ellagitannins inhibit proliferation of cancer cells is discussed.

Antioxidants↗
PubMed2005

Nucleotide sequence of Blackberry yellow vein associated virus, a novel member of the Closteroviridae.

The complete nucleotide sequence of a novel member of the genus Crinivirus (family Closteroviridae), isolated from blackberry and tentatively named Blackberry yellow vein associated virus, was determined. The virus possesses a bipartite genome. RNA 1 is 7,801 nucleotides in length and papain-like protease, methyltransferase, RNA helicase and RNA-dependent RNA polymerase motifs have been identified in the proteins coded for by this molecule. The polymerase is probably expressed via a +1 ribosomal frameshift, a common feature among members of the Closteroviridae. RNA 2 is 7,917 nucleotides long and encodes nine open reading frames, similar in size and position to orthologous genes of other criniviruses with the exception of a second hydrophobic peptide found near the 5' terminus of the molecule. Phylogenetic analysis revealed a close relationship between Blackberry yellow vein associated virus and Beet pseudo yellows virus, another crinivirus that infects small fruit crops.

Amino Acid Motifs↗
PubMed2006

Phylogenetic relationships, host affinity, and geographic structure of boreal and arctic endophytes from three major plant lineages.

Although associated with all plants, fungal endophytes (microfungi that live within healthy plant tissues) represent an unknown proportion of fungal diversity. While there is a growing appreciation of their ecological importance and human uses, little is known about their host specificity, geographic structure, or phylogenetic relationships. We surveyed endophytic Ascomycota from healthy photosynthetic tissues of three plant species (Huperzia selago, Picea mariana, and Dryas integrifolia, representing lycophytes, conifers, and angiosperms, respectively) in northern and southern boreal forest (Québec, Canada) and arctic tundra (Nunavut, Canada). Endophytes were recovered from all plant species surveyed, and were present in <1-41% of 2 mm2 tissue segments examined per host species. Sequence data from the nuclear ribosomal internal transcribed spacer region (ITS) were obtained for 280 of 558 isolates. Species-accumulation curves based on ITS genotypes remained non-asymptotic, and bootstrap analyses indicated that a large number of genotypes remain to be found. The majority of genotypes were recovered from only a single host species, and only 6% of genotypes were shared between boreal and arctic communities. Two independent Bayesian analyses and a neighbor-joining bootstrapping analysis of combined data from the nuclear large and small ribosomal subunits (LSUrDNA, SSUrDNA; 2.4 kb) showed that boreal and arctic endophytes represent Dothideomycetes, Sordariomycetes, Chaetothyriomycetidae, Leotiomycetes, and Pezizomycetes. Many well-supported phylotypes contained only endophytes despite exhaustive sampling of available sequences of Ascomycota. Together, these data demonstrate greater than expected diversity of endophytes at high-latitude sites and provide a framework for assessing the evolution of these poorly known but ubiquitous symbionts of living plants.

Ascomycota↗
PubMed2002

Effects of sanguiin H-6, a component of Sanguisorbae Radix, on lipopolysaccharide-stimulated nitric oxide production.

The present study was conducted to evaluate the effect of sanguiin H-6, a component of Sanguisorbae Radix, on the production of nitric oxide (NO), using macrophages activated by lipopolysaccharide (LPS). Sanguiin H-6 inhibited nitrite production, taken as an index for NO, in a concentration-dependent fashion. This compound decreased inducible NO synthase (iNOS) activity, with the inhibitory effect at a concentration of 25 microM being equal to that of the known iNOS inhibitor aminoguanidine at 50 microM. However, unlike aminoguanidine, sanguiin H-6 was associated with improved cell viability. Reverse transcription-polymerase chain reaction analysis revealed that the expression of iNOS mRNA in activated macrophages was suppressed by sanguiin H-6 in a concentration-dependent manner. In addition, sanguiin H-6 even at a low concentration showed a clear scavenging effect on the NO generated from sodium nitroprusside (an NO donor). These findings indicate that not only does sanguiin H-6 act directly as an NO scavenger, but it also inhibits NO production in LPS-activated macrophages by the concomitant inhibition of iNOS mRNA induction and enzyme activity.

Animals↗
PubMed2003

Involvement of three pathogenicity factors of Erwinia amylovora in the oxidative stress associated with compatible interaction in pear.

Erwinia amylovora, the causal agent of fire blight of Maloideae, induces in its susceptible host plants an oxidative burst as does an incompatible pathogen. In this paper we present evidence that the elicitation of this phenomenon is the result of the combined action of two Hrp effectors of the bacteria, HrpN and DspA. We also confirmed that desferrioxamine, the siderophore of E. amylovora, is necessary for the bacteria to tolerate high levels of hydrogen peroxide. Two other pathogenicity factors of the bacteria, the HrpW effector and the capsule, do not seem to play any role in the elicitation of the oxidative burst nor in the protection of the bacteria.

Erwinia↗
PubMed2002

Increase of nitrous oxide flux to the atmosphere upon nitrogen addition to red mangroves sediments.

Response of nitrous oxide N20 sediment/air flux to nitrogen addition was assessed in mangrove (Rhizophora mangle) sediments. Fluxes were enhanced with both ammonium and nitrate loading. Greatest fluxes (52 micromol m(-2) h(-1)) were obtained with ammonium addition and saturation was achieved with additions of 0.9 mol m(-2). Maximum flux following ammonium addition was 2785 times greater than control plots and 4.5 times greater during low tide than with equivalent ammonium addition at high tide. Nitrate enrichment resulted in exponential growth, with maximal mean flux of 36.7 micromolm(-2) h(-1) at 1.9 molm(-2); saturation was not achieved. Differential response to ammonium and nitrate, and to tide and elevation, indicate that microbial nitrification is responsible for most of the observed gas flux. Mangrove sediments constitute an important source of global atmospheric N20 and increases in nitrogen loading will lead to significant increases in the flux of this atmospherically active gas.

Air Pollutants↗
PubMed1992

Carbon dioxide laser surgery for skin disease.

Since it was developed in the 1960s, the carbon dioxide (CO2) laser has had an important role in the practice of dermatology. The CO2 laser has some advantages over conventional techniques used in dermatologic surgical treatment. It routinely provides a bloodless surgical field as well as unusual surgical precision. Although the CO2 laser is specifically indicated for certain conditions, in other situations, only marginal benefit may be noted in comparison with standard techniques such as scalpel surgical procedures, dermabrasion, cryosurgery, and electrosurgery. In this article, we briefly review the history and physics of the CO2 laser, its operation, and safety principles and discuss dermatologic conditions that are treated with the CO2 laser. We also describe 8 representative cases from our experience with more than 800 cases of CO2 laser treatment in the practice of dermatology at the Mayo Clinic since 1986.

Adult↗
PubMed1998

Cutaneous manifestations of systemic diseases.

Many aspects of dermatologic diagnosis are either of importance or interest to the nondermatologist, and there are many excellent textbooks available for guidance. This article focuses on four categories of conditions that are the source of frequent queries from the primary care setting: (1) common skin diseases that frequently mimic systemic illness, (2) common skin diseases that have important systemic associations, (3) common systemic diseases that have prominent cutaneous findings, and (4) the seldom seen but frequently raised concerns regarding cutaneous signs of internal malignancy.

Cellulitis↗
PubMed2001

First cyclotide from Hybanthus (Violaceae).

Hypa A, a novel macrocyclic polypeptide containing 30 amino acid residues, has been isolated from the n-butanol extract of the Argentine plant Hybanthus parviflorus. The sequence, cyclo-(SCVYIPCTITALLGCSCKNKVCYNGIPCAE), was determined by automated Edman degradation, quantitative amino acid analysis and nanospray MS/MS(2). Three intramolecular disulfide bridges stabilize the cyclic peptide backbone of hypa A. Using these structural features to classify the peptide as a cyclotide, we extended the distribution of that substance class to a new genus, and now propose a uniform nomenclature for cyclotides.

Amino Acid Sequence↗
PubMed2001

Stress induced carbazole phytoalexins in Glycosmis species.

Induced formation of a series of carbazole alkaloids was observed in leaves of Glycosmis parviflora and G. pentaphylla after wounding, UV-irradiation, and particularly after inoculation with the fungus Botrytis cinerea. Chemical variation between different provenances and even individuals of G. parviflora led to an accumulation of different derivatives from which three proved to be undescribed natural products. Their structures were identified by spectroscopic methods and named carbalexins A, B, and C. Bioautographic tests on TLC plates with Cladosporium herbarum exhibited strong antifungal activity for the new carbalexins as well as for the already known 2-hydroxy-3-methylcarbazole, but only weak effects for the pyranocarbazole glycoborinine. Detailed experiments with marked infection areas confirmed the restricted accumulation of carbazole derivatives which could not be detected in non-infected areas of the same leaf. Apart from carbazoles, in some individuals of G. parviflora an additional accumulation of the pyranoquinolones flindersine and methylflindersine was induced, which supports the already previously discussed biogenetic connections between carbazoles and prenylated quinolones.

Alkaloids↗
PubMed2001

Characterization of peroxidase-mediated chlorophyll bleaching in strawberry fruit.

Peroxidase (POX) from strawberry fruits was analyzed for its capacity to bleach chlorophyll. The partially purified enzyme preperation catalyzed the bleaching of chlorophylls and their derivatives in the presence of H(2)O(2) and phenolic compounds. The optimal reaction conditions were 35 degrees C, pH 5.2 and ionic strength equal to 0.2. The maximum activity was observed at 1 mM of H(2)O(2), while higher concentrations inhibited enzyme activity. Compounds with a high affinity to the heme group, radical scavengers and reducing agents, showed an inhibitory effect. Phenolic compounds such as umbelliferone, naringenin and p-substituted monophenols acted as cofactors. Instead, other phenolic compounds tested such as caffeic acid, catechin, ellagic acid, esculin and quercetin inhibited the activity of POX on chlorophylls. Phenolic compounds extracted from strawberry fruits showed an inhibitory effect on POX-chlorophyll bleaching activity, although this effect decreased markedly during ripening. POX showed higher affinity for compounds derived from chlorophyll a than from chlorophyll b, and the enzyme preferentially degraded chlorophyll derivatives with the Mg(2+) ion present and the phytol group removed. The POX-chlorophyll bleaching activity was found in all ripening stages from small green to ripe, the highest activity corresponding to large green fruits.

Chlorophyll↗
PubMed2002

Three anthrones from Rubus ulmifolius.

From the aerial parts of Rubus ulmifolius Schott three new anthrones, rubanthrone A, B and C, have been isolated. Their structures were established by spectral procedures including 1D and 2D NMR techniques and chemical derivatization. Rubanthrone A showed antimicrobial activity against Staphylococcus aureus at 4.5 mg/ml.

Anthracenes↗
PubMed2003

A family of polyketide synthase genes expressed in ripening Rubus fruits.

Quality traits of raspberry fruits such as aroma and color derive in part from the polyketide derivatives, benzalacetone and dihydrochalcone, respectively. The formation of these metabolites during fruit ripening is the result of the activity of polyketide synthases (PKS), benzalcetone synthase and chalcone synthase (CHS), during fruit development. To gain an understanding of the regulation of these multiple PKSs during fruit ripening, we have characterized the repertoire of Rubus PKS genes and studied their expression patterns during fruit ripening. Using a PCR-based homology search, a family of ten PKS genes (Ripks1-10) sharing 82-98% nucleotide sequence identity was identified in the Rubus idaeus genome. Low stringency screening of a ripening fruit-specific cDNA library, identified three groups of PKS cDNAs. Group 1 and 2 cDNAs were also represented in the PCR amplified products, while group 3 represented a new class of Rubus PKS gene. The Rubus PKS gene-family thus consists of at least eleven members. The three cDNAs exhibit distinct tissue-specific and developmentally regulated patterns of expression. RiPKS5 has high constitutive levels of expression in all organs, including developing flowers and fruits, while RiPKS6 and RiPKS11 expression is consistent with developmental and tissue-specific regulation in various organs. The recombinant proteins encoded by the three RiPKS cDNAs showed a typical CHS-type PKS activity. While phylogenetic analysis placed the three Rubus PKSs in one cluster, suggesting a recent duplication event, their distinct expression patterns suggest that their regulation, and thus function(s), has evolved independently of the structural genes themselves.

Amino Acid Sequence↗
PubMed2003

Enzymatic carotenoid cleavage in star fruit (Averrhoa carambola).

This paper presents the first description of an enzyme fraction exhibiting carotenoid cleavage activity isolated from fruit skin of Averrhoa carambola. Partial purification of the enzyme could be achieved by acetone precipitation, ultrafiltration (300 kDa, 50 kDa), isoelectric focusing (pH 3-10) and sodium dodecyl sulfate polyacrylamide gel electrophoresis (7.5%). In this way, an enzymatically active protein fraction was obtained, consisting of four proteins in the molecular weight range of between 12 and 90 kDa. Using beta-carotene as substrate, the enzyme activity was detected spectrophotometrically at 505 nm. The main reaction product, detected by GC analysis, was beta-ionone. This proves that the isolated enzymes are closely related to aroma metabolism and release of star fruit. The time constant of the reaction was 16.6 min, the Michaelis Constant K(m)=3.6 micromol 1(-1) and the maximum velocity V(max)=10.5 x 10(-3) micromol l(-1) s(-1) mg((Protein))(-1). The optimum temperature was 45 degrees C.

Carotenoids↗