1,720,957 research outputs found
Biological activities of the legume crops Melilotus officinalis and Lespedeza capitata for skin care and pharmaceutical applications
No full textThe search for natural principles is attracting much interest in the field of skin care. Fabaceae are major
agricultural crops and potential sources of bioactive compounds with possible applications in human
health and skin care. This study concerns the biological activities of the legume crops Melilotus officinalis
(L.) Pall. and Lespedeza capitata Michx. for their potential use in skin care applications. The effects
of plant ethanolic extracts at doses ranging from 0.25 to 50 g/mL (from 1 to 5000 g/mL in cell viability
assays) were evaluated using in vitro tests on HaCaT human keratinocytes, 46BR.1N fibroblasts,
and adipocyte cell cultures, and on matrix-degrading enzymes. MTT assay revealed weak effects on cell
viability (IC50 > 1000 g/mL) and significant increase of fibroblast growth rate with both extracts. Similar
induction of cell motility by the two extracts was observed on keratinocytes, while on fibroblasts
M. officinalis induced a stronger effect with respect to L. capitata. Cell-free enzymatic assays showed
stronger collagenase inhibition by L. capitata, while an ELISA assay revealed more efficient stimulation of
fibroblast collagen production by M. officinalis. Oil-Red-O adipocyte staining showed more pronounced
lipolytic effect of M. officinalis with respect to L. capitata. Both extracts showed the ability of stimulating
skin cells in order to promote tissue regeneration, prevent skin aging, and reduce fat deposition. In
most cases, different patterns of activation/inhibition were observed. Data indicate that these legume
crops could be profitably exploited in skin care applications, possibly in combined formulations for the
development of antiaging and anticellulite products
Oleuropein-enriched olive leaf extract affects calcium dynamics and impairs viability of malignant mesothelioma cells.
Full text linkMalignant mesothelioma is a poor prognosis cancer in urgent need of alternative therapies. Oleuropein, the major phenolic of
olive tree (Olea europaea L.), is believed to have therapeutic potentials for various diseases, including tumors. We obtained an
oleuropein-enriched fraction, consisting of 60% w/w oleuropein, fromolive leaves, and assessed its effects on intracellular Ca2+ and cell viability in mesothelioma cells. Effects of the oleuropein-enriched fraction on Ca2+ dynamics and cell viability were studied in the REN mesothelioma cell line, using fura-2 microspectrofluorimetry andMTT assay, respectively. Fura-2-loaded cells, transiently exposed to the oleuropein-enriched fraction, showed dose-dependent transient elevations of cytosolicCa2+ concentration ([Ca2+]i).
Application of standard oleuropein and hydroxytyrosol, and of the inhibitor of low-voltage T-type Ca2+ channels NNC-55-0396,
suggested that the effect is mainly due to oleuropein acting through its hydroxytyrosol moiety on T-type Ca2+ channels. The
oleuropein-enriched fraction and standard oleuropein displayed a significant antiproliferative effect, as measured on REN cells
by MTT cell viability assay, with IC50 of 22 g/mL oleuropein. Data suggest that our oleuropein-enriched fraction from olive leaf
extract could have pharmacological application in malignant mesothelioma anticancer therapy, possibly by targeting T-type Ca2+ channels and thereby dysregulating intracellular Ca2+ dynamics
Resveratrol induces intracellular Ca(2+) rise via T-type Ca(2+) channels in a mesothelioma cell line
No full textAbstract
AIMS:
Intracellular calcium (Ca(2+)) is known to play an important role in cancer development and growth. Resveratrol (Res) is a stilbene polyphenol occurring in several plant species and known for various possible beneficial effects, including its ability to inhibit proliferation and to induce apoptosis in cancer cells. This study was designed to determine whether Res affects Ca(2+) signaling in cancer cells.
MAIN METHODS:
We used the REN human mesothelioma cell line, as an in vitro cancer cell model, and the non-malignant human mesothelial MeT5A cell line, as normal cell model. Cytosolic Ca(2+) concentration was measured by the fluorescent indicator Fura-2. Immunofluorescence, Western blot, and siRNA technique were employed to assess the involvement of T-type Ca(2+) channels. Cell viability was determined by the calcein assay.
KEY FINDINGS:
REN cells transiently exposed to 1-10μM Res showed increasing peaks of Ca(2+) that were absent in Ca(2+)-free medium and were reduced by non-selective (Ni(2+)), and highly selective (NNC 55-0396) T-type Ca(2+) channels antagonist, and by siRNA knockout of Cav3.2T-type Ca(2+) channel gene. Dose-dependent curve of Res-induced Ca(2+) peaks showed a rightward shift in normal MeT-5A mesothelial cells (EC50=4.9μM) with respect to REN cells (EC50=2.7μM). Moreover, incubation with 3 and 10μM Res for 7days resulted in cell growth inhibition for REN, but not for MeT-5A cells.
SIGNIFICANCE:
Res induces Ca(2+) influx, possibly mediated through T-type Ca(2+) channels, with significant selectivity towards mesothelioma cells, suggesting a possible use as an adjuvant to chemotherapy drugs for mesothelioma clinical treatment
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Antiproliferative hydroxy-fatty acids from the fodder legume Stylosanthes guianensis
No full textStylosanthes guianensis is a fodder legume native from South America and widely grown worldwide. Dried plant material was purchased on the web and taxonomically identified by light and SEM microscopy, and morphological analysis of plants germinated from seeds. The plant was extracted with dichloromethane:2-propanol (9:1). Bioguided fractionation using calcein-AM cytotoxicity assay on HeLa and A431 tumor cells allowed to isolate a lipophilic fraction, endowed with strong cytotoxicity. By means of 1- and 2-D NMR, HPLC–MS, and HR-ESIMS it could be seen that the fraction was an inseparable mixture of complex lipids, mainly consisting of esterified 3-hydroxy fatty acids. Acidic methanolysis of the mixture yielded 3-OH C10 and C12 carboxylic acids, together with palmitic, stearic, and arachidonic acids. Mass values indicate the presence of dimeric and trimeric combinations of 3-hydroxy, C10/C12 acids, and C16/C18/C20 acids, linked via ester bond. Monomeric hydroxyl-fatty acids were also observed, in particular derivatives of mono-hydroxy and di-hydroxy linolenic, linoleic, and oleic acids. 3-O-acylated, esterified fatty acids are unusual in higher plants, and recall motifs of Gram-negative endotoxin lipid A. These oxylipins are likely to be responsible for the antiproliferative activity of S. guianensis, suggesting possible use of the plant in the development of antitumor drugs
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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