1,720,996 research outputs found
Metabolomics profiling, bio-pharmaceutical properties of Hypericum lanuginosum extracts by in vitro and in silico approaches
No full textHypericum species are important as a source of natural-bioactive compounds in the Turkish folk medicine. Among them, Hypericum lanuginosum has not been explored so far for its biological properties. The current study aimed to determine the antioxidant activity, enzyme inhibitory potential, and phenolic content (spectrophotometric and liquid chromatography/high resolution mass spectrometry (LC-HRMS) analysis) of different solvent extracts (ethyl acetate, methanol, and aqueous) of H. lanuginosum aerial parts. Twenty one phenolic compounds including phenolic acids, acylquinic acids, flavonoids and bioflavonoids were identified by LC-HRMS profiles. Quinic acid was the dominant compound in all H. lanuginosum extracts. The highest total phenolic (168.56 mg gallic acid equivalent (GAE)) and flavonoid (53.22 mg rutin equivalent (RE)) contents were observed in the aqueous extract. Also, the aqueous extract was the best antioxidant, showing the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) scavenging, ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), and activity in the phosphomolybdenum assay. The methanol extract exhibited the strongest metal chelating and inhibitory effect on alpha-amylase and tyrosinase. In contrast, the most efficient inhibitor of cholinesterases and alpha-glucosidase was the ethyl acetate extract. Docking showed that the selected compounds are all possible inhibitor candidates of tyrosinase. To conclude, each solvent extract of H. lanuginosum varied in its chemical and biological profile but overall, possess a good source of many natural agents which can be used to manage ailments inked with oxidative stress
Uncovering chemical profiles, biological potentials, and protection effect against ECM destruction in H2O2-treated HDF cells of the extracts of Stachys tundjeliensis
No full textThe genus Stachys L., one of the largest genera of the Lamiaceae family, is highly represented in Turkey. This study was conducted to determine the bio-pharmaceutical potential and phenolic contents of six different extracts from aerial parts of Stachys tundjeliensis. The obtained results showed that the ethanol extract exhibited the highest antioxidant activity in the antioxidant assays. Meanwhile, the ethanol extract displayed strong inhibitory activity against α-tyrosinase, the dichloromethane extract exhibited potent inhibition against butyrylcholinesterase, and the n-hexane extract against α-amylase. Based on ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry analysis, more than 90 secondary metabolites, including hydroxybenzoic acid, hydroxycinnamic acid, and their glycosides, acylquinic acids, phenylethanoid glycosides, and various flavonoids were identified or tentatively annotated in the studied S. tundjeliensis extracts. It was observed that the application of S. tundjeliensis eliminated H2O2-induced oxidative stress. It was determined that protein levels of phospho-nuclear factor kappa B (NF-κB), receptor for advanced glycation endproducts, and activator protein-1, which are activated in the nucleus, decreased, and the synthesis of matrix metalloproteinase (MMP)-2 and MMP-9 also decreased to basal levels. Overall, these findings suggest that S. tundjeliensis contains diverse bioactive compounds for the development of nutraceuticals or functional foods with potent biological properties
Multidirectional biological investigation and phytochemical profile of Rubus sanctus and Rubus ibericus
No full text1st International Conference on Natural Toxicology and Pharmacology (ICNTP) -- AUG 08-12, 2019 -- Guangzhou, PEOPLES R CHINAIn the present study, the biological properties, including, the enzyme inhibitory and antioxidant activities, as well as, the phytochemical profile of the ethyl acetate, methanol, and water extracts of Rubus sanctus Schreb. and Rubus ibericus Juz. leaves were determined using in vitro bioassays. Wide range of phytochemicals, including, hydroxybenzoic acids, hydroxycinnamic acids, acylquinic acids, ellagitannins, flavonoids, and triterpenoid saponins were determined using UHPLC-ESI/HRMS technique. The ethyl acetate and methanol extracts of the studied Rubus species effectively inhibited acetyl and butyryl cholinesterase. On the other hand, R. sanctus water extract showed low inhibition against alpha-amylase and prominent inhibitory action against alpha-glucosidase. Data collected from this study reported the radical scavenging and reducing potential of the studied Rubus species. Investigation of the protective effects of the different extracts of R. sanctus and R. ibericus in experimental model of ulcerative colitis was performed. The extracts were also tested on spontaneous migration of human colon cancer cells (HCT116) in wound healing experimental paradigm. Only R. sanctus methanol extract inhibited spontaneous HCT116 migration in the wound healing test. Our results suggested that R. sanctus and R. ibericus may be potential candidates as sources of biologically-active compounds for the development of nutraceuticals, pharmaceuticals, and/or cosmetics.Jinan Univ, Zhejiang Univ, Univ Macau, Univ Hong Kong, Int Assoc Dietet Nutr & Safety, Int Soc Chinese MedItalian Ministry of University (FAR)The study was supported by Italian Ministry of University (FAR grants): FAR 2018 granted to Prof. Claudio Ferrante; FAR 2017 granted to Prof. Giustino Orlando
Chemical profiling and pharmaco-toxicological activity of Origanum sipyleum extracts: Exploring for novel sources for potential therapeutic agents
No full textThe phytochemical, antiradical, and enzyme inhibition profile of three solvent extracts (ethyl acetate, methanol, water) of Origanum sipyleum were assessed. We also performed a pharmacological study in order to explore protective effects induced by extracts in inflamed colon. LC-MS analysis revealed that the extracts contained different classes of phenolics. The aqueous extract showed the highest antioxidant and acetylcholinesterase (AChE) inhibitory effects. Total phenol and flavonoid contents were highest in aqueous and ethyl acetate extract, respectively. All extracts were effective in reducing colon pro-oxidant and pro-inflammatory biomarkers. The extracts revealed also able to inhibit fungal and bacterial species involved in ulcerative colitis, including Candida albicans, Candida tropicalis, Staphylococcus aureus, and Staphylococcus thyphimurium. Finally, we also showed the antiproliferative effects exerted by the EA extracts on human colon cancer HCT116 cell line. Concluding, our results indicated that O. sipyleum extracts displayed promising therapeutic properties which warrants further validation. PRACTICAL APPLICATIONS: The present phytochemical and biological studies, including antioxidant, anti-inflammatory, and antimicrobic assessments, showed significant protective effects exerted by O. sipyleum extracts in an experimental model of ulcerative colitis. The results are intriguing and suggest potential applications O. sipyleum extracts as sources of natural agents for the management of clinical symptoms related to ulcerative colitis, characterized by increased burden of oxidative stress and microbiome dysbiosis
The most promising Southeastern European Tanacetum species: a review of chemical composition and biological studies
No full textSeveral species of the genus Tanacetum L. (Asteraceae) spread in the Southestern Europe are traditionally used as medicinal and aromatic plants, including T. vulgare, T. parthenium, T. macrophyllum, T. balsamita, T. poteriifolium. The review is focused on the phytochemical and pharmacological studies of these taxa. Major chemical constituents are acylquinic acids, sesquiterpenes, sesquiterpene lactones, methoxylated flavonoids. An in-depth depiction of more than 100 secondary metabolites was achieved in Tanacetum species by liquid chromatography-high resolution mass spectrometry. The ethnopharmacological studies indicate that species possess antioxidant, enzyme inhibitory and cytotoxic activity along with antimicrobial and antiviral effects. Reports revealed anti-inflamatory and neuromodulatory activity involved in the pharmacological approach in counteracting migraine attacks. Multivariate data analysis allowed the identification of the most discriminant metabolites and bioactivities in the herbal drugs. This review emphasizes T. vulgare, T. macrophyllum, T. balsamita and T. parthenium as potential raw material for health-promoting application in pharmaceutical area
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
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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