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| | 1. |
2011 Sep 19 |
Simultaneous isolation of artemisinin and its precursors from Artemisia annua L. by preparative RP-HPLC.
Tian N, Li J, Liu S, Huang J, Li X, Liu Z
Biomed Chromatogr. 2011 Sep 19; [Epub ahead of print]
Abstract
It is still a major challenge to simultaneously isolate artemisinin and its precursors, especially dihydroartemisinic acid and artemisinic acid, from herbal Artemisia annua. A rapid, economical and automatical chromatographic separation process to isolate and purify artemisinin, dihydroartemisinic acid and artemisinic acid at the same time on a preparative scale was developed. The procedure included solvent extraction of ground Artemisia annua leaves by refluxing and purification of crude extract by preparative reverse-phase high-performance liquid chromatography (RP-HPLC). Fractions containing artemisinin and its precursors were collected and identified by gas chromatography and mass spectrometry. High purity of artemisinin, dihydroartemisinic acid and artemisinic acid was obtained by preparative HPLC with a C(18) column and 60% acetonitrile in water as the mobile phase. The techniques described here are useful tools for the preparative-scale isolation of artemisinin and its precursors in a fast, cost-effective and environmental friendly manner. Copyright © 2011 John Wiley & Sons, Ltd.
[Pubmed: 21932380]
| | 2. |
2011 Jun 3 |
Rhodococcus artemisiae sp. nov., a new endophytic actinobacterium isolated from pharmaceutical plant Artemisia annua L.
Zhao GZ, Li J, Zhu WY, Tian SZ, Zhao LX, Yang LL, Xu LH, Li WJ
Int J Syst Evol Microbiol. 2011 Jun 3; [Epub ahead of print]
Abstract
A novel Gram-positive, non-motile actinobacterium, designated as strain YIM 65754T, was isolated from the stems of Artemisia annua L. collected from Yunnan province, south-west China. A polyphasic study was undertaken to establish the taxonomic position of this strain. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YIM 65754T form an evolutionary lineage within the genus Rhodococcus and formed a monophyletic lineage with Rhodococcus pyridinivorans DSM 44555T, Rhodococcus gordoniae W4937T and Rhodococcus rhodochrous DSM 43241T, with which it shared sequence similarities of 98.4%, 97.9% and 97.8%, respectively. However, DNA-CDNA relatedness demonstrated that strain YIM 65754T was distinct from its closest phylogenetic neighbours. Its cell-wall peptidoglycan contained meso-diaminopimelic acid (meso-DAP), arabinose, galactose, mannose and glucose (cell-wall chemotype IV sensu). The major menaquinone was MK-8(H2) and the predominant fatty acids were C16 : 0 (27.83%), iso-C15 : 0 2-OH/C16 : 1ω7c (20.21%) and 10-methyl C18 : 0 (17.50%). The DNA G+C content of the isolate was 66.2 mol%. On the basis of the phenotypic and phylogenetic evidence, the isolate is separate from previously described members of the genus Rhodococcus and represents a novel species in this genus, for which the name Rhodococcus artemisiae sp. nov. is proposed. The type strain is YIM 65754T (= CCTCC AA 209042T = DSM 45380T).
[Pubmed: 21642485]
| | 3. |
2011 Sep 23 |
Comparative Evaluation of Two Different Artemisia dracunculus L. Cultivars for Blood Sugar Lowering Effects in Rats.
Weinoehrl S, Feistel B, Pischel I, Kopp B, Butterweck V
Phytother Res. 2011 Sep 23; [Epub ahead of print]
Abstract
Recent concerns about the potential carcinogenicity of estragole and methyleugenol led a number of regulatory bodies to call for restrictions on the use of herbs that contain these constituents. A number of medicinal plants produce essential oils that contain estragole and methyleugenol, including Artemisia dracunculus L. (tarragon). Previous studies have proven the antidiabetic properties of tarragon. In order to address the safety concerns of estragole containing tarragon extracts, an extraction procedure was developed to minimize the estragole and methyleugenol content in tarragon extracts and the ethanol versus aqueous extracts from two Artemisia dracunculus cultivars (French and Russian tarragon) were tested for blood glucose lowering effects in rats. It could be demonstrated that aqueous extracts of both Artemisia cultivars did not contain detectable amounts of estragole and methyleugenol, whereas ethanol extracts (60% v/v) of the French cultivar contained higher levels of the aforementioned compounds than those of the Russian cultivar. Further testing revealed that Russian tarragon lowered blood glucose levels in rats after glucose challenge, with the ethanol extract being as active as the aqueous extract. The results suggest that by using adequate production procedures the amount of potentially harmful compounds in extracts can be limited without affecting the overall pharmacological activities of these preparations. Copyright © 2011 John Wiley & Sons, Ltd.
[Pubmed: 21953838]
| | 4. |
2011 Nov 9 |
Degradation of seed mucilage by soil microflora promotes early seedling growth of a desert sand dune plant.
Yang X, Baskin CC, Baskin JM, Zhang W, Huang Z
Plant Cell Environ. 2011 Nov 9; [Epub ahead of print]
Abstract
In contrast to the extensive understanding of seed mucilage biosynthesis, much less is known about how mucilage is biodegraded and what role it plays in the soil where seeds germinate. We studied seed mucilage biodegradation by a natural microbial community. High-performance anion-exchange chromatography (HPAEC) was used to determine monosaccharide composition in achene mucilage of Artemisia sphaerocephala. Mucilage degradation by the soil microbial community from natural habitats was examined by monosaccharide utilization tests using Biolog plates, chemical assays and phospholipid fatty acid (PLFA) analysis. Glucose (29.4%), mannose (20.3%) and arabinose (19.5%) were found to be the main components of achene mucilage. The mucilage was biodegraded to CO(2) and soluble sugars, and an increase in soil microbial biomass was observed during biodegradation. Fluorescence microscopy showed the presence of mucilage (or its derivatives) in seedling tissues after growth with fluorescein isothiocyanate (FITC)-labeled mucilage. The biodegradation also promoted early seedling growth in barren sand dunes, which was associated with a large soil microbial community that supplies substances promoting seedling establishment. We conclude that biodegradation of seed mucilage can play an ecologically important role in the life cycles of plants especially in harsh desert environments to which A. sphaerocephala is well-adapted.
[Pubmed: 22070663]
| | 5. |
2011 Dec 17 |
Antiproliferative effects of artemisinin on human breast cancer cells requires the downregulated expression of the E2F1 transcription factor and loss of E2F1-target cell cycle genes.
Tin AS, Sundar SN, Tran KQ, Park AH, Poindexter KM, Firestone GL
Anticancer Drugs. 2011 Dec 17; [Epub ahead of print]
Abstract
Artemisinin, a sesquiterpene phytolactone derived from Artemisia annua, is a potent antimalarial compound with promising anticancer properties, although the mechanism of its anticancer signaling is not well understood. Artemisinin inhibited proliferation and induced a strong G1 cell cycle arrest of cultured MCF7 cells, an estrogen-responsive human breast cancer cell line that represents an early-stage cancer phenotype, and effectively inhibited the in-vivo growth of MCF7 cell-derived tumors from xenografts in athymic nude mice. Artemisinin also induced a growth arrest of tumorigenic human breast cancer cell lines with preneoplastic and late stage cancer phenotypes, but failed to arrest the growth of a nontumorigenic human mammary cell line. Concurrent with the cell cycle arrest of MCF7 cells, artemisinin selectively downregulated the transcript and protein levels of the CDK2 and CDK4 cyclin-dependent kinases, cyclin E, cyclin D1, and the E2F1 transcription factor. Analysis of CDK2 promoter-luciferase reporter constructs showed that the artemisinin ablation of CDK2 gene expression was accounted for by the loss of CDK2 promoter activity. Chromatin immunoprecipitation revealed that artemisinin inhibited E2F1 interactions with the endogenous MCF7 cell CDK2 and cyclin E promoters. Moreover, constitutive expression of exogenous E2F1 prevented the artemisinin-induced cell cycle arrest and downregulation of CDK2 and cyclin E gene expression. Taken together, our results demonstrate that the artemisinin disruption of E2F1 transcription factor expression mediates the cell cycle arrest of human breast cancer cells and represents a critical transcriptional pathway by which artemisinin controls human reproductive cancer cell growth.
[Pubmed: 22185819]
| | 6. |
2011 Dec 9 |
Mining of miRNAs and potential targets from gene oriented clusters of transcripts sequences of the anti-malarial plant, Artemisia annua.
Pérez-Quintero AL, Sablok G, Tatarinova TV, Conesa A, Kuo J, López C
Biotechnol Lett. 2011 Dec 9; [Epub ahead of print]
Abstract
miRNAs involved in the biosynthesis of artemisinin, an anti-malarial compound form the plant Artemisia annua, have been identified using computational approaches to find conserved pre-miRNAs in available A. annua UniGene collections. Eleven pre-miRNAs were found from nine families. Targets predicted for these miRNAs were mainly transcription factors for conserved miRNAs. No target genes involved in artemisinin biosynthesis were found. However, miR390 was predicted to target a gene involved in the trichome development, which is the site of synthesis of artemisinin and could be a candidate for genetic transformation aiming to increase the content of artemisinin. Phylogenetic analyses were carried out to determinate the relation between A. annua and other plant pre-miRNAs: the pre-miRNA-based phylogenetic trees failed to correspond to known phylogenies, suggesting that pre-miRNA primary sequences may be too variable to accurately predict phylogenetic relations.
[Pubmed: 22160362]
| | 7. |
2011 Nov 23 |
Use of Artemisia annua as a natural coccidiostat in free-range broilers and its effects on infection dynamics and performance.
Almeida GF, Horsted K, Thamsborg SM, Kyvsgaard NC, Ferreira JF, Hermansen JE
Vet Parasitol. 2011 Nov 23; [Epub ahead of print]
Abstract
This work investigated the preventive effect of Artemisia annua L. dried leaves supplied as a botanical coccidiostat to two broiler genotypes reared in a Danish free-range system in a factorial experiment (two genotypes and ± supplement of dried A. annua leaves). The genotypes White Bresse L40, a pure slow-growing line, and Kosmos 8 Ross, a hybrid genotype with medium growing characteristics, were used. Broilers were raised indoor until 29-days-old and kept free of parasites. Twelve groups of 30 randomly selected broilers were placed in the range forming three replicates for each treatment combination. The paddocks were cultivated with a mix of grass and clover. A separate group of broilers was naturally infected with Eimeria spp. oocysts and five animals nominated as "seeders" were introduced to the above mentioned 12 groups, 10days after its formation, with each group consisting of 35 animals per plot. This infection strategy was meant to imitate the transmission pathway observed at farm level. Ten individual birds from each of the 12 groups, in total 120 animals of mixed sex, were monitored twice weekly for 30days for oocysts excretion. PCR of pooled faecal samples, oocyst morphology and localization upon necropsy were used to identify the Eimeria species involved in the infection. In general, broilers from both genotypes in the range coped well with a coccidia infection caused by Eimeria acervulina and Eimeria maxima as no clinical symptoms, or deaths, were reported during the experiment. In general, broilers supplemented with A. annua dried leaves showed a significantly (p<0.05) reduced number of excreted oocysts during the infection with no interaction to genotype. Females generally had a significantly higher shedding of oocysts than males (p<0.05). The overall body weight gain and the daily weight gain when infection was subdued showed a three-way interaction among genotype, sex and treatment - accounted mainly for the fact that Kosmos females responded positively to the Artemisia treatment while Kosmos males responded negatively, and only minor differences were found between sexes for the White Bresse genotype. In conclusion, supply of A. annua dried leaves as a botanical coccidiostat significantly reduced oocyst output in free ranged broilers and thus may form part of a strategy to prevent commercial losses.
[Pubmed: 22154969]
| | 8. |
2011 Aug 19 |
Inhibition effects of isolated compounds from Artemisia rubripes Nakai of the classical pathway on the complement system.
Jung S, Lee JH, Lee YC, Moon HI
Immunopharmacol Immunotoxicol. 2011 Aug 19; [Epub ahead of print]
Abstract
The study evaluated the anticomplement activity from isolated compounds from Artemisia rubripes Nakai from South Korea on the classical pathway. In the previous works, Artemisia rubripes chloroform extracts showed inhibitory activity against complement system. The chromatographic separation of a chloroform chloride extract of Artemisia rubripes led to the isolation of three compounds. Their structures were characterized to be scopoletin (1), 11,(13)-triene-6,12-olide (2), and 1β,6α-dihydroxy-4(15)-eudesmene (3) by spectroscopic data. This is the first report of anticomplement activity of isolated compounds from Artemisia rubripes.
[Pubmed: 21854097]
| | 9. |
2012 Feb 14 |
Characterization of Profilin Polymorphism in Pollen with a Focus on Multifunctionality
Jimenez-Lopez, Morales, Castro, Volkmann, Rodríguez-García, Alché
PLoS One 2012 Feb 14;7(2). published online before print
Abstract
Profilin, a multigene family involved in actin dynamics, is a multiple partners-interacting protein, as regard of the presence of at least of three binding domains encompassing actin, phosphoinositide lipids, and poly-L-proline interacting patches. In addition, pollen profilins are important allergens in several species like Olea europaea L. (Ole e 2), Betula pendula (Bet v 2), Phleum pratense (Phl p 12), Zea mays (Zea m 12) and Corylus avellana (Cor a 2). In spite of the biological and clinical importance of these molecules, variability in pollen profilin sequences has been poorly pointed out up until now. In this work, a relatively high number of pollen profilin sequences have been cloned, with the aim of carrying out an extensive characterization of their polymorphism among 24 olive cultivars and the above mentioned plant species. Our results indicate a high level of variability in the sequences analyzed. Quantitative intra-specific/varietal polymorphism was higher in comparison to inter-specific/cultivars comparisons. Multi-optional posttranslational modifications, e.g. phosphorylation sites, physicochemical properties, and partners-interacting functional residues have been shown to be affected by profilin polymorphism. As a result of this variability, profilins yielded a clear taxonomic separation between the five plant species. Profilin family multifunctionality might be inferred by natural variation through profilin isovariants generated among olive germplasm, as a result of polymorphism. The high variability might result in both differential profilin properties and differences in the regulation of the interaction with natural partners, affecting the mechanisms underlying the transmission of signals throughout signaling pathways in response to different stress environments. Moreover, elucidating the effect of profilin polymorphism in adaptive responses like actin dynamics, and cellular behavior, represents an exciting research goal for the future.
[Pubmed: 22348028]
| | 10. |
2012 Feb 21 |
Herbal medicines for the management of irritable bowel syndrome: A comprehensive review
Rahimi, Abdollahi
World J Gastroenterol 2012 Feb 21;18(7):589-600.
Abstract
Irritable bowel syndrome (IBS) is a functional gut disorder with high prevalence. Because of various factors involved in its pathophysiology and disappointing results from conventional IBS medications, the treatment of IBS is challenging and use of complementary and alternative medicines especially herbal therapies is increasing. In this paper, electronic databases including PubMed, Scopus, and Cochrane library were searched to obtain any in vitro, in vivo or human studies evaluating single or compound herbal preparations in the management of IBS. One in vitro, 3 in vivo and 23 human studies were included and systematically reviewed. The majority of studies are about essential oil of Menta piperita as a single preparation and STW 5 as a compound preparation. Some evaluated herbs such as Curcuma xanthorriza and Fumaria officinalis did not demonstrate any benefits in IBS. However, it seems there are many other herbal preparations such as those proposed in traditional medicine of different countries that could be studied and investigated for their efficacy in management of IBS.
[Pubmed: 22363129]
| | 11. |
2012 Feb 16 |
Reciprocal Effects of Litter from Exotic and Congeneric Native Plant Species via Soil Nutrients
Meisner, de Boer, Cornelissen, van der Putten
PLoS One 2012 Feb 16;7(2). published online before print
Abstract
Invasive exotic plant species are often expected to benefit exclusively from legacy effects of their litter inputs on soil processes and nutrient availability. However, there are relatively few experimental tests determining how litter of exotic plants affects their own growth conditions compared to congeneric native plant species. Here, we test how the legacy of litter from three exotic plant species affects their own performance in comparison to their congeneric natives that co-occur in the invaded habitat. We also analyzed litter effects on soil processes. In all three comparisons, soil with litter from exotic plant species had the highest respiration rates. In two out of the three exotic-native species comparisons, soil with litter from exotic plant species had higher inorganic nitrogen concentrations than their native congener, which was likely due to higher initial litter quality of the exotics. When litter from an exotic plant species had a positive effect on itself, it also had a positive effect on its native congener. We conclude that exotic plant species develop a legacy effect in soil from the invaded range through their litter inputs. This litter legacy effect results in altered soil processes that can promote both the exotic plant species and their native congener.
[Pubmed: 22359604]
| | 12. |
2012 Feb 16 |
The Effects of Warming-Shifted Plant Phenology on Ecosystem Carbon Exchange Are Regulated by Precipitation in a Semi-Arid Grassland
Xia, Wan
PLoS One 2012 Feb 16;7(2). published online before print
Abstract
The longer growing season under climate warming has served as a crucial mechanism for the enhancement of terrestrial carbon (C) sink over the past decades. A better understanding of this mechanism is critical for projection of changes in C cycling of terrestrial ecosystems.
[Pubmed: 22359660]
| | 13. |
2012 Mar 13 |
Fungal endophyte diversity in sarracenia.
Glenn A, Bodri MS
PLoS ONE. 2012;7(3):e32980. Epub 2012 Mar 13.
Abstract
Fungal endophytes were isolated from 4 species of the carnivorous pitcher plant genus Sarracenia: S. minor, S. oreophila, S. purpurea, and S. psittacina. Twelve taxa of fungi, 8 within the Ascomycota and 4 within the Basidiomycota, were identified based on PCR amplification and sequencing of the internal transcribed spacer sequences of nuclear ribosomal DNA (ITS rDNA) with taxonomic identity assigned using the NCBI nucleotide megablast search tool. Endophytes are known to produce a large number of metabolites, some of which may contribute to the protection and survival of the host. We speculate that endophyte-infected Sarracenia may benefit from their fungal associates by their influence on nutrient availability from within pitchers and, possibly, by directly influencing the biota within pitchers.
[Pubmed: 22427921]
| | 14. |
2012 Mar 16 |
Plant Diversity Changes during the Postglacial in East Asia: Insights from Forest Refugia on Halla Volcano, Jeju Island
Dolezal, Altman, Kopecky, Cerny, Janecek, Bartos, Petrik, Srutek, Leps, Song
PLoS One 2012 Mar 16;7(3). published online before print
Abstract
Understanding how past climate changes affected biodiversity is a key issue in contemporary ecology and conservation biology. These diversity changes are, however, difficult to reconstruct from paleoecological sources alone, because macrofossil and pollen records do not provide complete information about species assemblages. Ecologists therefore use information from modern analogues of past communities in order to get a better understanding of past diversity changes. Here we compare plant diversity, species traits and environment between late-glacial Abies, early-Holocene Quercus, and mid-Holocene warm-temperate Carpinus forest refugia on Jeju Island, Korea in order to provide insights into postglacial changes associated with their replacement. Based on detailed study of relict communities, we propose that the late-glacial open-canopy conifer forests in southern part of Korean Peninsula were rich in vascular plants, in particular of heliophilous herbs, whose dramatic decline was caused by the early Holocene invasion of dwarf bamboo into the understory of Quercus forests, followed by mid-Holocene expansion of strongly shading trees such as maple and hornbeam. This diversity loss was partly compensated in the Carpinus forests by an increase in shade-tolerant evergreen trees, shrubs and lianas. However, the pool of these species is much smaller than that of light-demanding herbs, and hence the total species richness is lower, both locally and in the whole area of the Carpinus and Quercus forests. The strongly shading tree species dominating in the hornbeam forests have higher leaf tissue N and P concentrations and smaller leaf dry matter content, which enhances litter decomposition and nutrient cycling and in turn favored the selection of highly competitive species in the shrub layer. This further reduced available light and caused almost complete disappearance of understory herbs, including dwarf bamboo.
[Pubmed: 22438890]
| | 15. |
2012 Feb 24 |
The Abundance of Pink-Pigmented Facultative Methylotrophs in the Root Zone of Plant Species in Invaded Coastal Sage Scrub Habitat
Irvine, Brigham, Suding, Martiny
PLoS One 2012 Feb 24;7(2). published online before print
Abstract
Pink-pigmented facultative methylotrophic bacteria (PPFMs) are associated with the roots, leaves and seeds of most terrestrial plants and utilize volatile C1 compounds such as methanol generated by growing plants during cell division. PPFMs have been well studied in agricultural systems due to their importance in crop seed germination, yield, pathogen resistance and drought stress tolerance. In contrast, little is known about the PPFM abundance and diversity in natural ecosystems, let alone their interactions with non-crop species. Here we surveyed PPFM abundance in the root zone soil of 5 native and 5 invasive plant species along ten invasion gradients in Southern California coastal sage scrub habitat. PPFMs were present in every soil sample and ranged in abundance from 102 to 105 CFU/g dry soil. This abundance varied significantly among plant species. PPFM abundance was 50% higher in the root zones of annual or biennial species (many invasives) than perennial species (all natives). Further, PPFM abundance appears to be influenced by the plant community beyond the root zone; pure stands of either native or invasive species had 50% more PPFMs than mixed species stands. In sum, PPFM abundance in the root zone of coastal sage scrub plants is influenced by both the immediate and surrounding plant communities. The results also suggest that PPFMs are a good target for future work on plant-microorganism feedbacks in natural ecosystems.
[Pubmed: 22383990]
| | 16. |
2012 Mar 22 |
Particular characteristics of allergic symptoms in tropical environments: follow up to 24 months in the FRAAT birth cohort study.
Acevedo N, Sanchez J, Zakzuk J, Bornacelly A, Quiroz C, Alvarez A, Puello M, Mendoza K, Martinez D, Mercado D, Jimenez S, Caraballo L
BMC Pulm Med. 2012 Mar 22;12(1):13. Epub 2012 Mar 22.
Abstract
ABSTRACT: BACKGROUND: Early wheezing and asthma are relevant health problems in the tropics. Mite sensitization is an important risk factor, but the roles of others, inherent in poverty, are unknown. We designed a birth-cohort study in Cartagena (Colombia) to investigate genetic and environmental risk factors for asthma and atopy, considering as particular features perennial exposure to mites, parasite infections and poor living conditions. METHODS: Pregnant women representative of the low-income suburbs of the city were randomly screened for eligibility at delivery; 326 mother-infant pairs were included at baseline and biological samples were collected from birth to 24 months for immunological testing, molecular genetics and gene expression analysis. Pre and post-natal information was collected using questionnaires. RESULTS: 94% of families were from the poorest communes of the city, 40% lacked sewage and 11% tap-water. Intestinal parasites were found as early as 3 months; by the second year, 37.9% of children have had parasites and 5.22% detectable eggs of Ascaris lumbricoides in stools (Median 3458 epg, IQR 975-9256). The prevalence of "wheezing ever" was 17.5% at 6 months, 31.1% at 12 months and 38.3% at 24 months; and recurrent wheezing (3 or more episodes) 7.1% at 12 months and 14.2% at 24 months. Maternal rhinitis [aOR 3.03 (95%CI 1.60-5.74), p = 0.001] and male gender [aOR 2.09 (95%CI 1.09 - 4.01), p = 0.026], increased risk for wheezing at 6 months. At 24 months, maternal asthma was the main predisposing factor for wheezing [aOR 3.65 (95%CI 1.23-10.8), p = 0.01]. Clinical symptoms of milk/egg allergy or other food-induced allergies were scarce (1.8%) and no case of atopic eczema was observed. CONCLUSIONS: Wheezing is the most frequent phenotype during the first 24 months of life and is strongly associated with maternal asthma. At 24 months, the natural history of allergic symptoms is different to the "atopic march" described in some industrialized countries. This cohort is representative of socially deprived urban areas of underdeveloped tropical countries. The collection of biological samples, data on exposure and defined phenotypes, will contribute to understand the gene/environment interactions leading to allergy inception and evolution.
[Pubmed: 22439773]
| | 17. |
2012 Feb 09 |
Dihydroartemisinin exhibits antitumor activity toward hepatocellular carcinoma in vitro and in vivo.
Zhang CZ, Zhang H, Yun J, Chen GG, Lai PB
Biochem. Pharmacol. 2012 May 1;83(9):1278-89. Epub 2012 Feb 09.
Abstract
Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua L., has been shown to exhibit inhibitory effects on human cancer cells. However, its antitumor ability toward hepatocellular carcinoma (HCC) has not been studied. In this study, we demonstrated that DHA significantly inhibited HCC cell growth in vitro and in vivo via inducing G2/M cell cycle arrest and apoptosis. The induction of p21 and the inhibition of cyclin B and CDC25C contributed to DHA-induced G2/M arrest. DHA-induced apoptosis was associated with mitochondrial membrane depolarization, release of cytochrome c, activation of caspases, and DNA fragmentation. Activation of caspase 9 and caspase 3, but not caspase 8, was detected in DHA-treated cells. Attenuation of apoptosis in cells pretreated with Z-VAD-FMK suggested the involvement of caspase cascade. Furthermore, p53 facilitated apoptosis caused by DHA. Bcl-2 family proteins were also responsible for DHA-induced apoptosis. DHA exposure decreased Mcl-1 expression but increased the levels of Noxa and active Bak. Bak was released from the Mcl-1/Bak complex due to the decline of Mcl-1. Further study revealed that Mcl-1 was rapidly degraded in DHA-treated cells and that DHA-induced apoptosis was largely inhibited by overexpression of Mcl-1 or RNAi-mediated decrease of Bak and Noxa. In a HCC-xenograft mouse model, the intraperitoneal injection of DHA resulted in significant inhibition of HCC xenograft tumors. Taken together, our data, for the first time, demonstrate the potential antitumor activity of DHA in HCC.
[Pubmed: 22342732]
| | 18. |
2012 Mar 22 |
Deregulation of Sucrose-Controlled Translation of a bZIP-Type Transcription Factor Results in Sucrose Accumulation in Leaves
Thalor, Berberich, Lee, Yang, Zhu, Imai, Takahashi, Kusano
PLoS One 2012 Mar 22;7(3). published online before print
Abstract
Sucrose is known to repress the translation of Arabidopsis thaliana AtbZIP11 transcript which encodes a protein belonging to the group of S (S - stands for small) basic region-leucine zipper (bZIP)-type transcription factor. This repression is called sucrose-induced repression of translation (SIRT). It is mediated through the sucrose-controlled upstream open reading frame (SC-uORF) found in the AtbZIP11 transcript. The SIRT is reported for 4 other genes belonging to the group of S bZIP in Arabidopsis. Tobacco tbz17 is phylogenetically closely related to AtbZIP11 and carries a putative SC-uORF in its 5′-leader region. Here we demonstrate that tbz17 exhibits SIRT mediated by its SC-uORF in a manner similar to genes belonging to the S bZIP group of the Arabidopsis genus. Furthermore, constitutive transgenic expression of tbz17 lacking its 5′-leader region containing the SC-uORF leads to production of tobacco plants with thicker leaves composed of enlarged cells with 3–4 times higher sucrose content compared to wild type plants. Our finding provides a novel strategy to generate plants with high sucrose content.
[Pubmed: 22457737]
| | 19. |
2012 Mar 27 |
A geochemical study of toxic metal translocation in an urban brownfield wetland.
Qian Y, Gallagher FJ, Feng H, Wu M
Environ Pollut. 2012 Mar 27;166C:23-30. Epub 2012 Mar 27.
Abstract
Rhizosphere soil and dominant plant samples were collected at a brownfield site in New Jersey, USA, during summer 2005 to evaluate plant metal uptake from the contaminated soils. Metal concentrations varied from 4.25 to 978 μg g(-1) for As, 9.68-209 μg g(-1) for Cr, 23.9-1870 μg g(-1) for Cu, and 24.8-6502 μg g(-1) for Zn. A wide range of metal uptake efficiencies in the roots, stems and leaves was found in this study. Data showed that (1) Betula populifolia has high Zn, Cu and As accumulations in the root, and high concentrations of Cu and Zn in the stem and the leaf; (2) Rhus copallinum has high accumulation of Zn and Cr in the leaf and Cu in the stem; (3) Polygonum cuspidatum has high accumulations of Cu and As in the root; and (4) Artemisia vulgaris shows high Cu accumulation in the leaf and the stem.
[Pubmed: 22459711]
| | 20. |
2012 Mar 29 |
Exploring the Switchgrass Transcriptome Using Second-Generation Sequencing Technology
Wang, Zeng, Iyer, Bryant, Mockler, Mahalingam
PLoS One 2012 Mar 29;7(3). published online before print
Abstract
Switchgrass (Panicum virgatum L.) is a C4 perennial grass and widely popular as an important bioenergy crop. To accelerate the pace of developing high yielding switchgrass cultivars adapted to diverse environmental niches, the generation of genomic resources for this plant is necessary. The large genome size and polyploid nature of switchgrass makes whole genome sequencing a daunting task even with current technologies. Exploring the transcriptional landscape using next generation sequencing technologies provides a viable alternative to whole genome sequencing in switchgrass.
[Pubmed: 22479570]
| | 21. |
2012 Apr 5 |
Soil Microbial Properties and Plant Growth Responses to Carbon and Water Addition in a Temperate Steppe: The Importance of Nutrient Availability
Ma, Huang, Guo, Wang, Xiao
PLoS One 2012 Apr 5;7(4). published online before print
Abstract
Global climatic change is generally expected to stimulate net primary production, and consequently increase soil carbon (C) input. The enhanced C input together with potentially increased precipitation may affect soil microbial processes and plant growth.
[Pubmed: 22496905]
| | 22. |
2012 Mar 30 |
Light and Heavy Fractions of Soil Organic Matter in Response to Climate Warming and Increased Precipitation in a Temperate Steppe
Song, Niu, Zhang, Yang, Li, Wan
PLoS One 2012 Mar 30;7(3). published online before print
Abstract
Soil is one of the most important carbon (C) and nitrogen (N) pools and plays a crucial role in ecosystem C and N cycling. Climate change profoundly affects soil C and N storage via changing C and N inputs and outputs. However, the influences of climate warming and changing precipitation regime on labile and recalcitrant fractions of soil organic C and N remain unclear. Here, we investigated soil labile and recalcitrant C and N under 6 years' treatments of experimental warming and increased precipitation in a temperate steppe in Northern China. We measured soil light fraction C (LFC) and N (LFN), microbial biomass C (MBC) and N (MBN), dissolved organic C (DOC) and heavy fraction C (HFC) and N (HFN). The results showed that increased precipitation significantly stimulated soil LFC and LFN by 16.1% and 18.5%, respectively, and increased LFC∶HFC ratio and LFN∶HFN ratio, suggesting that increased precipitation transferred more soil organic carbon into the quick-decayed carbon pool. Experimental warming reduced soil labile C (LFC, MBC, and DOC). In contrast, soil heavy fraction C and N, and total C and N were not significantly impacted by increased precipitation or warming. Soil labile C significantly correlated with gross ecosystem productivity, ecosystem respiration and soil respiration, but not with soil moisture and temperature, suggesting that biotic processes rather than abiotic factors determine variations in soil labile C. Our results indicate that certain soil carbon fraction is sensitive to climate change in the temperate steppe, which may in turn impact ecosystem carbon fluxes in response and feedback to climate change.
[Pubmed: 22479373]
| | 23. |
2012 Apr 12 |
Cement dust pollution induces toxicity or deficiency of some essential elements in wild plants growing around a cement factory.
Mutlu S, Atici O, Gulen Y
Toxicol Ind Health. 2012 Apr 12; [Epub ahead of print]
Abstract
In the present study, it was aimed to determine the effects of cement dust pollution on contents of some significant essential elements (P, S, K, Ca, Fe and Cl) in wild plants (Medigago varia, Anchusa leptophylla, Euphorbia orientalis, Lactuca serriola, Artemisia spicigera, Crambe orientalis, Convolvulus sepium and Senecio vernalis) using wavelength-dispersive spectrometer X-ray fluorescence technique. Plant samples were collected from different locations around a cement factory which is located at Askale about 50 km from Erzurum (Turkey). The element contents in the plant specimens that existed in both 0-100 m (dense dusted) and 2000 m (undusted) areas were compared. P, S, K and Cl contents were found to be high in the plants growing in areas 0-100 m from the cement factory, compared to same plants at 2000 m far from the factory. However, Ca and Fe contents were determined to be low in plants growing in 0-100 m area from the factory. Results of the study can contribute to understand how mineral deficiency and toxicity lead to detrimental effects on plant growth and development in the fields contaminated by cement dust.
[Pubmed: 22499269]
| | 24. |
2012 Mar 27 |
An Ethanol Extract of Artemisia iwayomogi Activates PPARδ Leading to Activation of Fatty Acid Oxidation in Skeletal Muscle
Cho, Jeong, Sohn, Seo, Kim, Lee
PLoS One 2012 Mar 27;7(3). published online before print
Abstract
Although Artemisia iwayomogi (AI) has been shown to improve the lipid metabolism, its mode of action is poorly understood. In this study, a 95% ethanol extract of AI (95EEAI) was identified as a potent ligand of peroxisome proliferator-activated receptorδ (PPARδ) using ligand binding analysis and cell-based reporter assay. In cultured primary human skeletal muscle cells, treatment of 95EEAI increased expression of two important PPARδ-regulated genes, carnitine palmitoyl-transferase-1 (CPT1) and pyruvate dehydrogenase kinase isozyme 4 (PDK4), and several genes acting in lipid efflux and energy expenditure. Furthermore, 95EEAI stimulated fatty acid oxidation in a PPARδ-dependent manner. High-fat diet-induced obese mice model further indicated that administration of 95EEAI attenuated diet-induced obesity through the activation of fatty acid oxidation in skeletal muscle. These results suggest that a 95% ethanol extract of AI may have a role as a new functional food material for the prevention and/or treatment of hyperlipidermia and obesity.
[Pubmed: 22479450]
| | 25. |
2012 Apr 12 |
Seed Mucilage Improves Seedling Emergence of a Sand Desert Shrub
Yang, Baskin, Baskin, Liu, Huang
PLoS One 2012 Apr 12;7(4). published online before print
Abstract
The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand burial. In a greenhouse experiment, two types of Artemisia sphaerocephala achenes (intact and demucilaged) were exposed to different combinations of burial depth (0, 5, 10, 20, 40 and 60 mm) and irrigation regimes (low, medium and high, which simulated the precipitation amount and frequency in May, June and July in the natural habitat, respectively). Seedling emergence increased with increasing irrigation. It was highest at 5 mm sand burial depth and ceased at burial depths greater than 20 mm in all irrigation regimes. Mucilage significantly enhanced seedling emergence at 0, 5 and 10 mm burial depths in low irrigation, at 0 and 5 mm burial depths in medium irrigation and at 0 and 10 mm burial depths in high irrigation. Seed mucilage also reduced seedling mortality at the shallow sand burial depths. Moreover, mucilage significantly affected seedling emergence time and quiescence and dormancy percentages. Our findings suggest that seed mucilage plays an ecologically important role in successful seedling establishment of A. sphaerocephala by improving seedling emergence and reducing seedling mortality in stressful habitats of the sandy desert environment.
[Pubmed: 22511952]
| | 26. |
2012 Apr 25 |
Effects of Mowing on Methane Uptake in a Semiarid Grassland in Northern China
Zhang, Guo, Niu, Wang, Shao, Li
PLoS One 2012 Apr 25;7(4). published online before print
Abstract
Mowing is a widely adopted management practice for the semiarid steppe in China and affects CH4 exchange. However, the magnitude and the underlying mechanisms for CH4 uptake in response to mowing remain uncertain.
[Pubmed: 22558280]
| | 27. |
2012 Apr 23 |
Secondary Metabolites from Plants Inhibiting ABC Transporters and Reversing Resistance of Cancer Cells and Microbes to Cytotoxic and Antimicrobial Agents
Wink, Ashour, El-Readi
Front Microbiol 2012 Apr 23;3. published online before print
Abstract
Fungal, bacterial, and cancer cells can develop resistance against antifungal, antibacterial, or anticancer agents. Mechanisms of resistance are complex and often multifactorial. Mechanisms include: (1) Activation of ATP-binding cassette (ABC) transporters, such as P-gp, which pump out lipophilic compounds that have entered a cell, (2) Activation of cytochrome p450 oxidases which can oxidize lipophilic agents to make them more hydrophilic and accessible for conjugation reaction with glucuronic acid, sulfate, or amino acids, and (3) Activation of glutathione transferase, which can conjugate xenobiotics. This review summarizes the evidence that secondary metabolites (SM) of plants, such as alkaloids, phenolics, and terpenoids can interfere with ABC transporters in cancer cells, parasites, bacteria, and fungi. Among the active natural products several lipophilic terpenoids [monoterpenes, diterpenes, triterpenes (including saponins), steroids (including cardiac glycosides), and tetraterpenes] but also some alkaloids (isoquinoline, protoberberine, quinoline, indole, monoterpene indole, and steroidal alkaloids) function probably as competitive inhibitors of P-gp, multiple resistance-associated protein 1, and Breast cancer resistance protein in cancer cells, or efflux pumps in bacteria (NorA) and fungi. More polar phenolics (phenolic acids, flavonoids, catechins, chalcones, xanthones, stilbenes, anthocyanins, tannins, anthraquinones, and naphthoquinones) directly inhibit proteins forming several hydrogen and ionic bonds and thus disturbing the 3D structure of the transporters. The natural products may be interesting in medicine or agriculture as they can enhance the activity of active chemotherapeutics or pesticides or even reverse multidrug resistance, at least partially, of adapted and resistant cells. If these SM are applied in combination with a cytotoxic or antimicrobial agent, they may reverse resistance in a synergistic fashion.
[Pubmed: 22536197]
| | 28. |
2012 Apr 24 |
Anyone for an aperitif? Yes, but only a Braulio DOC with its certified proteome.
Fasoli E, D'Amato A, Citterio A, Righetti PG
J Proteomics. 2012 Apr 24; [Epub ahead of print]
Abstract
The trace proteome of a Braulio aperitif (a 21% alcohol beverage, named after a mountain in the Val di Stelvio, Italy) has been investigated via capture with combinatorial peptide ligand libraries (CPLL, ProteoMiner). This aperitif is made with an infusion of 13 mountain herbs and berries, among which four are officially indicated in the label: Achillea moschata, juniper (Juniperus communis subsp. alpina) berries, absinthe (Artemisia absinthium) and gentian (Gentiana alpina) roots. Via capture with CPLLs at pH 7.0 and 2.2 we were able to identify 29 unique gene products, among which the PR5 (parasite resistance) allergen Jun r 3.2, a 25kDa species from Juniperus rigida. Due to the paucity of data on these alpine herbs, it was difficult to attribute these proteins to the specific plant extracts presumably present in this beverage; however most of the species identified indeed belong to alpine herbs and plants, living in a habitat between 1000 and 2000m of elevation. Most of them are enzymes, spanning a Mr range from 10 to 65kDa. It is hoped that such a proteomic signature should help tracking counterfeited products sold on the market.
[Pubmed: 22554908]
| | 29. |
2012 Apr 25 |
Influence of Plant Polyphenols and Medicinal Plant Extracts on Antibiotic Susceptibility of Escherichia Coli.
Smirnova G, Samoilova Z, Muzyka N, Oktyabrsky O
J Appl Microbiol. 2012 Apr 25; [Epub ahead of print]
Abstract
Aims: To investigate the influence of polyphenols and plant extracts on the susceptibility of Escherichia coli to antibiotics. Methods and Results: Susceptibility of Escherichia coli to antibiotics in the presence of extracts and polyphenols was estimated by determination of the minimum inhibitory concentrations (MICs). To study gene expression we used strains of E. coli carrying fusions between promoters of genes katG, sodA, iucC and structural β-galactosidase gene. Treatment with polyphenols and some plant extracts significantly decreased the antibacterial effects of antibiotics, to a larger extent, ciprofloxacin. The most remarkable protective effect was observed for the extracts of Chamerion (Epilobium) angustifolium, Filipendula vulgaris, Tanacetum vulgare and Serratula coronata. These extracts increased the MICs of ciprofloxacin by four and more times. In case of kanamycin extracts of Artemisia austriaca and Artemisia pontica increased MICs by four and eight times, respectively. Polyphenol quercetin also caused protective effect against ciprofloxacin, increasing the MIC by four times. A positive correlation was found between protective effects of polyphenols and extracts and their antioxidant activity. Conclusion: Medicinal plant extracts and polyphenols may protect cells of Escherichia coli against antibiotic toxicity. Significance and Impact of the Study: The results of the present study may be used to enhance the efficiency of antibacterial therapies. © 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.
[Pubmed: 22533708]
| | 30. |
2012 Apr 17 |
Allergen Micro-Bead Array for IgE Detection: A Feasibility Study Using Allergenic Molecules Tested on a Flexible Multiplex Flow Cytometric Immunoassay
Pomponi, Bernardi, Liso, Palazzo, Tuppo, Rafaiani, Santoro, Labrada, Ciardiello, Mari, Scala
PLoS One 2012 Apr 17;7(4). published online before print
Abstract
Allergies represent the most prevalent non infective diseases worldwide. Approaching IgE-mediated sensitizations improved much by adopting allergenic molecules instead of extracts, and by using the micro-technology for multiplex testing.
[Pubmed: 22530068]
| | 31. |
2012 Jul |
Development of Monacolin K-Enriched Ganghwayakssuk (Artemisia princeps Pamp.) by Fermentation with Monascus pilosus.
Lee DS, Lee I
J. Microbiol. Biotechnol. 2012 Jul;22(7):975-80.
Abstract
Monacolin K-enriched ganghwayakssuk (Artemisia princeps Pamp.) was developed by fermentation with Monascus sp. Among the 15 Monascus spp. isolated previously from Monascus fermentation products, Monascus pilosus KMU108 produced 2,219 mg/kg of monacolin K during ganghwayakssuk fermentation with no detectable citrinin. The optimum concentrations of ganghwayakssuk and glucose determined from the response surface methodology (RSM) design were 2.2% and 3.8%, respectively. By applying these conditions, the monacolin K productivity was increased to 3,007 mg/kg after 15 days of fermentation. On the other hand, other characteristics such as the total content of flavonoids and phenolic compounds, and the antioxidant activity were relatively unchanged. Therefore, Monascusfermented ganghwayakssuk is an excellent biomaterial for the development of functional foods because of its high level of monacolin K, known to lower cholesterol levels.
[Pubmed: 22580317]
| | 32. |
2012 Mar 18 |
Standardized flavonoid-rich fraction of Artemisia princeps Pampanini cv. Sajabal induces apoptosis via mitochondrial pathway in human cervical cancer HeLa cells.
Ju HK, Lee HW, Chung KS, Choi JH, Cho JG, Baek NI, Chung HG, Lee KT
J Ethnopharmacol. 2012 May 7;141(1):460-8. Epub 2012 Mar 18.
Abstract
Artemisia princeps Pampanini is widely used in Eastern traditional medicine for the treatment of circulatory disorders, such as, dysmenorrhea, hematuria, hemorrhoids, and inflammation, and is also used to treat chronic conditions, such as, cancers, ulcers, and digestive disorders.
[Pubmed: 22449440]
| | 33. |
2012 Apr 1 |
Diversity of Woodland Communities and Plant Species along an Altitudinal Gradient in the Guancen Mountains, China
Meng, Zhang, Li
ScientificWorldJournal 2012 Apr 1;2012. published online before print
Abstract
Study on plant diversity is the base of woodland conservation. The Guancen Mountains are the northern end of Luliang mountain range in North China. Fifty-three quadrats of 10 m × 20 m of woodland communities were randomly established along an altitudinal gradient. Data for species composition and environmental variables were measured and recorded in each quadrat. To investigate the variation of woodland communities, a Two-Way Indicator Species Analysis (TWINSPAN) and a Canonical Correspondence Analysis (CCA) were conducted, while species diversity indices were used to analyse the relationships between species diversity and environmental variables in this study. The results showed that there were eight communities of woodland vegetation; each of them had their own characteristics in composition, structure, and environment. The variation of woodland communities was significantly related to elevation and also related to slope, slope aspect, and litter thickness. The cumulative percentage variance of species-environment relation for the first three CCA axes was 93.5%. Elevation was revealed as the factor which most influenced community distribution and species diversity. Species diversity was negatively correlated with elevation, slope aspect, and litter thickness, but positively with slope. Species richness and heterogeneity increased first and then decreased but evenness decreased significantly with increasing elevation. Species diversity was correlated with slope, slope aspect, and litter thickness.
[Pubmed: 22566768]
| | 34. |
2012 Mar 20 |
Transcriptome sequencing of field pea and faba bean for discovery and validation of SSR genetic markers.
Kaur S, Pembleton L, Cogan N, Savin K, Leonforte T, Paull J, Materne M, Forster J
BMC Genomics. 2012 Mar 20;13(1):104. Epub 2012 Mar 20.
Abstract
ABSTRACT: BACKGROUND: Field pea (Pisum sativum L.) and faba bean (Vicia faba L.) are cool-season grain legume species that provide rich sources of food for humans and fodder for livestock. To date, both species have been relative 'genomic orphans' due to limited availability of genetic and genomic information. A significant enrichment of genomic resources is consequently required in order to understand the genetic architecture of important agronomic traits, and to support germplasm enhancement, genetic diversity, population structure and demographic studies. RESULTS: cDNA samples obtained from various tissue types of specific field pea and faba bean genotypes were sequenced using 454 Roche GS FLX Titanium technology. A total of 720,324 and 304,680 reads for field pea and faba bean, respectively, were de novo assembled to generate sets of 70,682 and 60,440 unigenes. Consensus sequences were compared against the genome of the model legume species Medicago truncatula Gaertn., as well as that of the more distantly related, but better-characterised genome of Arabidopsis thaliana L.. In comparison to M. truncatula coding sequences, 11,737 and 10,179 unique hits were obtained from field pea and faba bean. Totals of 22,057 field pea and 18,052 faba bean unigenes were subsequently annotated from GenBank. Comparison to the genome of soybean (Glycine max L.) resulted in 19,451 unique hits for field pea and 16,497 unique hits for faba bean, corresponding to c. 35% and 30%% of the known gene space, respectively. Simple sequence repeat (SSR)-containing expressed sequence tags (ESTs) were identified from consensus sequences, and totals of 2,397 and 802 primer pairs were designed for field pea and faba bean. Subsets of 96 EST-SSR markers were screened for validation across modest panels of field pea and faba bean cultivars, as well as related non-domesticated species. For field pea, 86 primer pairs successfully obtained amplification products from one or more template genotypes, of which 59% revealed polymorphism between 6 genotypes. In the case of faba bean, 81 primer pairs displayed successful amplification, of which 48% detected polymorphism. CONCLUSIONS: The generation of EST datasets for field pea and faba bean has permitted effective unigene identification and functional sequence annotation. EST-SSR loci were detected at incidences of 14-17%, permitting design of comprehensive sets of primer pairs. The subsets from these primer pairs proved highly useful for polymorphism detection within Pisum and Vicia germplasm.
[Pubmed: 22433453]
| | 35. |
2012 Apr 13 |
Changes to Airborne Pollen Counts across Europe
Ziello, Sparks, Estrella, Belmonte, Bergmann, Bucher, Brighetti, Damialis, Detandt, Galán, Gehrig, Grewling, Gutiérrez Bustillo, Hallsdóttir, Kockhans-Bieda, De Linares, Myszkowska, Pàldy, Sánchez, Smith, Thibaudon, Travaglini, Uruska, Valencia-Barrera, Vokou, Wachter, de Weger, Menzel
PLoS One 2012 Apr 13;7(4). published online before print
Abstract
A progressive global increase in the burden of allergic diseases has affected the industrialized world over the last half century and has been reported in the literature. The clinical evidence reveals a general increase in both incidence and prevalence of respiratory diseases, such as allergic rhinitis (common hay fever) and asthma. Such phenomena may be related not only to air pollution and changes in lifestyle, but also to an actual increase in airborne quantities of allergenic pollen. Experimental enhancements of carbon dioxide (CO) have demonstrated changes in pollen amount and allergenicity, but this has rarely been shown in the wider environment. The present analysis of a continental-scale pollen data set reveals an increasing trend in the yearly amount of airborne pollen for many taxa in Europe, which is more pronounced in urban than semi-rural/rural areas. Climate change may contribute to these changes, however increased temperatures do not appear to be a major influencing factor. Instead, we suggest the anthropogenic rise of atmospheric CO levels may be influential.
[Pubmed: 22514618]
| | 36. |
2012 May 4 |
Impact of Grazing on Soil Carbon and Microbial Biomass in Typical Steppe and Desert Steppe of Inner Mongolia
Liu, Zhang, Chang, Kan, Lin
PLoS One 2012 May 4;7(5). published online before print
Abstract
The potential of grazing lands to sequester carbon must be understood to develop effective soil conservation measures and sustain livestock production. Our objective was to evaluate the effects of grazing on soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) in Typical steppe and Desert steppe ecosystems, which are both important grassland resources for animal grazing and ecological conservation in China, and to derive region-specific soil C changes associated with different stocking rates (ungrazed, UG; lightly grazed, LG; moderately grazed, MG; heavily grazed, HG). This study substantiated that significant higher SOC, TN and MBC appeared with the treatment of LG in typical steppe. From 2004 to 2010, grazing treatments increased soil carbon storage in desert steppe, which was partly due to the grazing history. The higher MBC concentration and MBC/SOC suggest a great potential for carbon sequestration in the desert steppe ecosystem. The greater MBC in desert steppe than typical steppe was mainly the result of higher precipitation and temperature, instead of soil substrate. The change of MBC and the strong positive relationships between MBC and SOC indicated that MBC in the soil was a sensitive index to indicate the dynamics of soil organic carbon in both steppes in Inner Mongolia of China.
[Pubmed: 22574161]
| | 37. |
2012 May 14 |
Spasmolytic activity of Artemisia copa aqueous extract and isolated compounds.
Gorzalczany S, Moscatelli V, Acevedo C, Ferraro G
Nat Prod Res. 2012 May 14; [Epub ahead of print]
Abstract
Artemisia copa Phil. (Compositae) is used in popular medicine as a digestive and for gastric pains. The effects of A. copa aqueous extract and its isolated compounds were evaluated on isolated rat jejunum. The extract inhibited non-competitively the cumulative concentration-response curves induced by acetylcholine and CaCl(2). The tonic jejunum contractions induced by 80 mM KCl were inhibited by A. copa. Relaxant effects of A. copa on the tonic contraction induced by 25 mM KCl, [EC(50): 0.94 mg mL(-1) (0.64-1.39)], was not inhibited by glibenclamide, TEA, l-NAME or methylene blue. Chrysoeriol, spinacetin and luteolin (30 µg mL(-1)), produced an antagonism on the CaCl(2) concentration-response curve, showing an inhibition of the maximum contractions (70.0% ± 5.0%, 49.1% ± 4.5% and 77.0% ± 3.5% of E (max), respectively), whereas tricin did not inhibit when the same concentration was used. A. copa exerts spasmolytic activity by blocking calcium channels and three isolated compounds could be, at least partly, responsible for the effect.
[Pubmed: 22577954]
| | 38. |
2012 Jul |
Artemisinic acid is a regulator of adipocyte differentiation and C/EBP δ expression.
Lee J, Kim MH, Lee JH, Jung E, Yoo ES, Park D
J. Cell. Biochem. 2012 Jul;113(7):2488-99.
Abstract
Adipocyte dysfunction is associated with the development of obesity. In this study, artemisinic acid, which was isolated from Artemisia annua L., inhibited adipogenic differentiation of human adipose tissue-derived mesenchymal stem cells (hAMSCs) and its mechanism of action was determined. The mRNA levels of peroxidase proliferation-activated receptor (PPAR) γ and CCAAT/enhancer binding protein (C/EBP) α, late adipogenic factors, were reduced by artemisinic acid. Moreover, the mRNA levels of the PPAR γ target genes lipoprotein lipase, CD36, adipocyte protein, and liver X receptor were down-regulated by artemisinic acid. Artemisinic acid reduced expression of the C/EBP δ gene without impacting C/EBP β. In addition, attempts to elucidate a possible mechanism underlying the artemisinic acid-mediated effects revealed that reduced expression of the C/EBP δ gene was mediated by inhibiting Jun N-terminal kinase (JNK). Additionally, artemisinic acid also reduced the expression of the adipogenesis-associated genes glucose transporter-4 and vascular endothelial growth factor. In addition to the interference of artemisinic acid with adipogenesis, artemisinic acid significantly attenuated tumor necrosis factor-α-induced secretion of interleukin-6 by undifferentiated hAMSCs, thus influencing insulin resistance and the inflammatory state characterizing obesity. Taken together, these findings indicate that inhibiting adipogenic differentiation of hAMSCs by artemisinic acid occurs primarily through reduced expression of C/EBP δ, which is mediated by the inhibition of JNK and suggest that aremisinic acid may be used as a complementary treatment option for obesity associated with metabolic syndrome. J. Cell. Biochem. 113: 2488-2499, 2012. © 2012 Wiley Periodicals, Inc.
[Pubmed: 22396222]
| | 39. |
2012 Apr 19 |
An Alternative Paradigm for the Role of Antimalarial Plants in Africa
Maranz
ScientificWorldJournal 2012 Apr 19;2012. published online before print
Abstract
Most investigations into the antimalarial activity of African plants are centered on finding an indigenous equivalent to artemisinin, the compound from which current frontline antimalarial drugs are synthesized. As a consequence, the standard practice in ethnopharmacological research is to use in vitro assays to identify compounds that inhibit parasites at nanomolar concentrations. This approach fails to take into consideration the high probability of acquisition of resistance to parasiticidal compounds since parasite populations are placed under direct selection for genetic that confers a survival advantage. Bearing in mind Africa's long exposure to malaria and extensive ethnobotanical experimentation with both therapies and diet, it is more likely that compounds not readily overcome by Plasmodium parasites would have been retained in the pharmacopeia and cuisine. Such compounds are characterized by acting primarily on the host rather than directly targeting the parasite and thus cannot be adequately explored in vitro. If Africa's long history with malaria has in fact produced effective plant therapies, their scientific elucidation will require a major emphasis on in vivo investigation.
[Pubmed: 22593717]
| | 40. |
2012 Feb 05 |
Artemisia absinthium (AA): a novel potential complementary and alternative medicine for breast cancer.
Shafi G, Hasan TN, Syed NA, Al-Hazzani AA, Alshatwi AA, Jyothi A, Munshi A
Mol. Biol. Rep. 2012 Jul;39(7):7373-9. Epub 2012 Feb 05.
Abstract
Natural products have become increasingly important in pharmaceutical discoveries, and traditional herbalism has been a pioneering specialty in biomedical science. The search for effective plant-derived anticancer agents has continued to gain momentum in recent years. The present study aimed to investigate the role of crude extracts of the aerial parts of Artemisia absinthium (AA) extract in modulating intracellular signaling mechanisms, in particular its ability to inhibit cell proliferation and promote apoptosis in a human breast carcinoma estrogenic-unresponsive cell line, MDA-MB-231, and an estrogenic-responsive cell line, MCF-7. Cells were incubated with various concentrations of AA, and anti-proliferative activity was assessed by MTT assays, fluorescence microscopy after propidium iodide staining, western blotting and cell cycle analysis. Cell survival assays indicated that AA was cytotoxic to both MDA-MB-231 and MCF-7 cells. The morphological features typical of nucleic staining and the accumulation of sub-G1 peak revealed that the extract triggered apoptosis. Treatment with 25 μg/mL AA resulted in activation of caspase-7 and upregulation of Bad in MCF-7 cells, while exposure to 20 μg/mL AA induced upregulation of Bcl-2 protein in a time-dependent response in MDA-MB-231 cells. Both MEK1/2 and ERK1/2 was inactivated in both cell lines after AA treatment in a time-dependent manner. These results suggest that AA-induced anti-proliferative effects on human breast cancer cells could possibly trigger apoptosis in both cell lines through the modulation of Bcl-2 family proteins and the MEK/ERK pathway. This might lead to its possible development as a therapeutic agent for breast cancer following further investigations.
[Pubmed: 22311047]
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