1,720,994 research outputs found
In vitro anti-urease, antioxidant activities and phytochemical composition of Geranium purpureum
No full textThe aim of this study was to evaluate for the first time phenolic compounds amount, antioxidant and anti-urease effects of ethanol extract from Geranium purpureum aerial parts. Also the phenolic compounds in the ethanol extract were analysed by HPLC-DAD and confirmed by liquid chromatography with quadrupole time-of-flight mass spectrometry using targeted MS/MS techniques with accurate mass measurement. The phenolic compounds were identified as caffeic acid derivative, quinic acid, galloyl-hexoside, malic acid, gallic acid, methyl gallate hexoside, chlorogenic acid, caffeic acid, rutin, dicaffeoyl quinic acid and quercetin. In the present study, the results of all three antioxidant assays showed that the ethanol extract had higher DPPH and ABTS radical scavenging activity than ascorbic acid and BHT. In addition, according to the results obtained, ethanol extract showed moderate metal chelating and anti-urease activity. Therefore, ethanol extract can be used in both medicine and food industry as a natural antioxidant and anti-urease agents in the future
Qualitative and quantitative phytochemical analysis and in-vitro biological activity of Rheum ribes L. different parts
No full textThe methanol extracts from different parts of Rheum ribes were subjected to qualitative and quantitative phytochemical and in vitro biological activity (antioxidant, anti-urease, anticholinesterase). Qualitative phytochemical tests were performed using standard analysis methods and these studies revealed the presence of phenolics and tannins. Following this, a quantitative determination of total phenolics and tannins contents was carried out. The antioxidant activity of the extracts were assayed using DPPH, FRAP TEAC/ABTS and CUPRAC techniques. In addition, the anti-urease and anticholinesterase activity of the extracts were examined using indophenol and Ellman methods, respectively. In this study, it was determined that the macerated flowers extract contained higher total phenolic and tannins contents than the other extracts. According to the results obtained from the antioxidant experiment, the macerated extract of flowers showed the strongest ABTS.+ scavenging and ferric reducing antioxidant power activity. The macerated leaves and Soxhlet radix extracts exhibited the strongest DPPH. scavenging and cupric reducing antioxidant activity, respectively. The young shoots extracts obtained using the Soxhlet methods showed the highest anticholinesterase activity. All extracts obtained from different parts of the plant were found to have very low anti-urease activity when compared to the anti-urease activity of standard compound. Therefore, methanol extracts from plant's flowers, leaves and young shoots can be used as a natural antioxidant and anticholinesterase agent respectively, for the pharmaceutical and food industry in the future
IN VITRO ANTIOXIDANT ACTIVITY OF EIGHT WILD EDIBLE PLANTS IN BURSA PROVINCE OF TURKEY
No full textThe antioxidant properties of ethanolic extracts from eight wild edible plants, which were collected in both fresh edible as vegetable and flowering (inedible) periods were investigated by employing various established in vitro systems: DPPH free radical scavenging, ABTS radical cation scavenging and metal chelating activity. Results showed that ethanol extracts of Rumex pulcher, A. undulata subsp. hybrida and Campanula lyrata, which were collected in edible periods exhibited the highest DPPH free radical scavenging activity and ABTS(.+) scavenging activity. Moreover, Asparagus acutifolius, Galium aparine and Campanula lyrata, which were collected in edible periods exhibited the highest metal chelating activity. The results obtained from this study showed that R. pulcher, A. undulata subsp. hybrida, C lyrata, A. acutifolius and G. aparine, which were collected in edible periods can be used as sources of natural antioxidants in food industry
Camellia Sinensis Leaves Hydroalcoholic Extract Improves the Alzheimer’s Disease-Like Alterations Induced by Type 2 Diabetes in Rats
No full textObjective: Novel investigations have confirmed that hyperglycemia is strictly associated with the development of cognitive impairment and dementia. Sodium-dependent glucose transporter (SGLT) inhibitors, which are oral antidiabetic drugs, are currently being investigated as the medication in Alzheimer's disease (AD). In our study, Camellia sinensis (green tea), which inhibits sodium-dependent glucose transporter-1 (SGLT-1), was used in the treatment of type 2 diabetes mellitus (T2DM)-induced AD-like alterations via its antidiabetic effects. Methods: High-fat diet/streptozotocin-treated rat model was chosen to provide T2DM-induced AD-like alterations. Antidiabetic effects were evaluated with the measurement of blood glucose level (BGL), oral glucose tolerance test (OGTT), and insulin tolerance test (ITT). On the other hand, novel object recognition test (NORT), open field test (OFT), passive avoidance test (PAT), and Morris's water maze (MWM) test were performed to investigate the anti-Alzheimer's effects of C. Sinensis. Results: C. sinensis tolerated BGL for a short time but metformin, the first medication prescribed for T2DM, tolerated BGL during the test for 120 min. C. sinensis increased the number of square crosses and the frequency of grooming activity in a similar manner to metformin in OFT. C. sinensis treatment improved exploratory behavior and memory retention components in NORT. The step-through latency decreased in HFD/STZ-treated rat model but it improved with metformin and C. sinensis treatment in PAT. According to the results obtained by the MWM test, C. sinensis treatment slightly improved learning. Conclusion: C. sinensis improved short-term memory and increased the locomotor activity in rats according to the results obtained by NORT, OFT, and PA
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Antioxidant, Anti-urease Activities and Genotoxic Effects of Terfezia Claveryi Methanol Extracts on Human Lymphocytes
No full textObjective: Terfezia claveryi is a dark brown color truffle and has been used extensively in human diet in Turkey. Therefore; it is an important issue to determine their biological activities and toxicity. This study aims to investigate the antioxidant and anti-urease effects of T. claveryi methanol extracts and to evaluate the genotoxicity of each extract. Methods: The antioxidant activities of methanol extracts were examined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate (ABTS) and ferric reducing/antioxidant power (FRAP) methods. The amount of total phenolic compounds contained in the extracts was determined using the Folin-Ciocalteu reagent (FCR) method. Anti-urease activities of methanol extracts were evaluated by indophenol method. In addition, potential DNA damaging effects of T. claveryi extracts on human lymphocytes were determined by the alkaline comet assay. Results: UM extract exhibited higher DPPH radical scavenging activity than MM extract [the concentration of the substance which provides the inhibition of 50% of the radical (IC50): 0.77 +/- 0.01 mg/mL, 1.17 +/- 0.02 mg/mL, respectively, p<0.0001] however, lower activity than standard (p<0.0001). Both extracts in different concentrations of T. claveryi caused DNA damage (p<0.0001) compared with solvent control DMSO. Also, total comet scores was higher in cells which had been incubated with MM extract (p<0.05). UM extract exhibited higher ferric reducing and anti-urease activity than MM extract but not found statistically different; also activities of both extract were found lower than positive controls of each methods (p<0.0001). Conclusion: T. claveryi methanol extracts induced genotoxicity on lymphocytes and showed very low antioxidant activity compared to standards. This preliminary study should be confirmed with further studies and in different cell lines
Investigation of the Effects of Biological Activity and Steeping Time of Four Different Black Teas Commercially Valuable in Turkey
No full textObjective: The aim of this study was to compare the phenolic, tannins contents and biological activities (antioxidant, anticholinesterase) of four different black teas commercially valuable in Turkey. Subsequently, to examine the effect of the steeping time on the chemical contents (phenolic and tannins contents) and biological activities of the samples. Methods: The antioxidant activities of samples were examined by 2,2-diphenyl-1-picryl-hydrazyl (DPPH), cupric reducing antioxidant capacity (CUPRAC) and ferric reducing/antioxidant power (FRAP) methods. The amount of total phenolic and tannins contents contained in the samples was determined using the Folin-Ciocalteu reagent (FCR) method. In addition, the anticholinesterase activities of different samples were evaluated by Ellman method. Results: According to the results obtained, filtered tea bag (FT) sample obtained after 5 min steeping exhibited stronger DPPH radical scavenging activity than other samples. In addition, it was found that powder ceylon tea (PCT) samples obtained after 60 min and 10 min steeping had the highest FRAP and CUPRAC values respectively. In this study, it was also determined that the PCT samples obtained after 5 min, 10 min, 15 min, and 30 min steeping contained higher phenolic and tannins contents than the other samples. In anticholinesterase experiment, powder tea (PT) sample obtained after 5 min steeping was found to have the strongest anticholinesterase activity. Conclusion: As a result, it was determined that the amount of phenolic contents generally increased with the infusion time. It was also found that the antioxidant, anticholinesterase activities and tannins content of the tea samples did not show significant change due to the time of the infusion
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