1,720,992 research outputs found
The standardised G115 Panax ginseng C.A. Meyer extract: a review of its properties and usage
No full textGinseng (Panax ginseng C.A. Meyer, ginseng) has been the most precious and renowned tonic drug in traditional Chinese medicine. Although the original discovery of its therapeutic efficacy has been lost in antiquity, believers in ginseng as a panacea have sought, cultivated, preserved and extracted its essences for the treatment of a wide range of ailments. Many patients have used aqueous and alcoholic extracts of ginseng during convalescence, particularly where previous health problem(s) resulted in some degree of debilitation, and a corresponding deficit in mental, physical or other functional capacities. An impressive body of information has been accumulated and scientific research has documented and reviewed the useful effects of P. ginseng C.A. Meyer. The high variability in composition of the marketed products clearly affects the results of clinical studies. The availability of the standardised ginseng extract G115® has made it possible to generate reproducible results in animal studies and human clinical research.
Active constituents found in most ginseng species include ginsenosides, polysaccharides, peptides, polyacetylenic alcohols, fatty acids and trace elements. It is generally believed that ginsenosides and their metabolites are the most important components determining the pharmacological effects of ginseng. Ginsenosides are triterpene saponins of the dammaran series. They are divided into three groups, classified according to their chemical structures: 20(S)-protopanaxadiols, 20(S)-protopanaxatriols and the RO ginsenosides. The variability in the pharmacological activities of the various ginseng species may be related to the different composition of proportions of ginsenosides.
One of the most common standardised extracts, used in many studies, is G115®, which contains 4% ginsenosides. In view of the wide variations, both qualitative and quantitative, standardisation must control the total amount of ginsenosides.
Several clinical studies have been conducted with the standardised P. ginseng extract G115®. Here we briefly review only double-blind, placebo-controlled trials that are judged to be of scientific relevance for the clinical profile of the product. The efficacy of G115® on physical performance still needs to be confirmed in Good Clinical Practice (GCP) settings. Several clinical studies with ginseng have not shown any significant effect on the enhancement of physical performance. The ability of G115® to increase endurance and vitality, on the other hand, has been demonstrated in a number of non-GCP studies. The efficacy of G115® in relieving menopausal symptoms is supported by two studies, one of GCP quality. Efficacy in improving cognitive function has been extensively reviewed. Intake of G115® in acute and multiple doses is associated with improvements in cognitive function. A series of studies has assessed the effects of G115® in various volunteer populations using a widely validated and highly sensitive computerised cognitive test system, the Cognitive Drug Research (CDR) assessment system. Several preclinical studies have indicated that G115® may have immunomodulatory properties. These findings have been confirmed in two clinical studies. The efficacy and safety of G115® for potentiating vaccination against the common cold and/or influenza syndrome in a randomised, double-blind, placebo-controlled, parallel-group, multicentre study were determined. Moreover, the effects of G115® in reducing the bacterial count in the bronchial system of patients undergoing an acute attack of chronic bronchitis has been investigated in an open pilot study.
The safety profile of G115® has been well established both from clinical studies in healthy volunteers and patients and from its use for over 30 years as a marketed medicinal product in many countries worldwide. Few clinical studies on G115® report adverse effects. In general, the lack of reported adverse effects suggests that they are few, and those present are very minor. On the other hand, a baseline level of adverse effects should be expected and is always present, even for placebo groups in clinical trials. A total of 1075 subjects have been treated with G115® to date in clinical trials. Seventy-one subjects experienced minor adverse effects but no serious events were reported. The most commonly reported adverse events were headache, itching, sore throat, skin rash, dry mouth, acne and diarrhoea, with no difference between placebo and G115®. In all trials, no changes in safety laboratory parameters were seen
Comparison of the potency of different brands of serenoa repens extract on 5alpha-reductase types I and II in prostatic co-cultured epithelial and fibroblast cells
No full textBackground: Serenoa repens extract is the phytotherapeutic agent most frequently used for the treatment of the urological symptoms caused by benign prostatic hyperplasia. There are many extracts in the market and each manufacturer uses different extraction processes; for this reason, it's possible that one product is not equivalent to another. The aim of this study was to compare the activity of different extracts of Serenoa repens marketed in Italy. Methods: The following extracts were tested on 10 day co-cultured epithelial and fibroblast cells by a 5alpha-reductase activity assay: Permixon(R), Saba(R), Serpens(R), Idiprost(R), Prostamev(R), Profluss(R) and Prostil(R). In order to assess the variability in Serenoa repens products, 2 different batches for each brand were evaluated. Results and Conclusions: All extracts tested, albeit variably, are able to inhibit both isoforms of 5alpha-reductase. However, the potency of the extracts appears to be very different, as well as the potencies of 2 different batches of the same extract. This is probably due to qualitative and quantitative differences in the active ingredients. So, the product of each company must be tested to evaluate the clinical efficacy and bioactivity
Comparison of the potency of 10 different brands of Serenoa repens extracts
No full textBACKGROUND:
The extract of Serenoa repens is the phytopharmaceutical product most often used for the treatment of urological symptoms associated with benign prostatic hyperplasia (BPH). Several extracts are commercially available but extraction processes vary between manufacturers and thus not all these products are equivalent in terms of active ingredient content and composition of preparations.
AIM:
As there is a paucity of comparative studies, we compared the activity of different extracts of Serenoa repens widely available on the world market.
MATERIALS AND METHODS:
Beltrax Uno, Permicaps, Permixon, Prostadyn, Prostagutt, Prostamen, Prostamol Uno, ProstaX, Urocaps and Urogutt were assayed for 5-alpha-reductase activity on 10 day fibroblasts and epithelial cells cocultures. Human fibroblast growth factor (hFGF)-induced-proliferation inhibition was also assayed.
RESULTS:
As to extract activity, differences were observed between the tested extracts, but all were able to inhibit 5-a-reductase types I and II isoenzymes (5alphaR-I and 5alphaR-II) as well as fibroblast proliferation.
CONCLUSIONS:
Extract potency differs between products and so does proliferation inhibition potency. Quantitative and qualitative variations in the active ingredient are likely to account for these differences
In vitro and in vivo pharmacokinetic/pharmacodynamic activity of clofoctol
No full textThe aim of the study was to examine the in vitro susceptibility of clinical isolates of respiratory pathogens to clofoctol compared with amoxicillin and erythromycin, and to characterize the pharmacokinetic/pharmacodynamic (PK/PD) relationships of clofoctol using a murine pneumonia infection model. Strains clinically isolated from patients between 2005 and 2009 were used to examine susceptibility: penicillin-susceptible Streptococcus pneumoniae, penicillin-resistant S. pneumoniae, Streptococcus pyogenes, methicillin-susceptible Staphylococcus aureus, methicillin-resistant S. aureus, and Haemophilus influenzae. The in vitro activity of clofoctol against clinical isolates has essentially remained unchanged over recent years. The MIC50 and MIC90 of clofoctol against penicillin-resistant S. pneumoniae are lower than that of amoxicillin and erythromycin. The area under curve/minimum inhibitory concentration (AUC/MIC) ratio is the PK/PD parameter that best correlates with in vivo clofoctol efficacy; the value of AUC/MIC required to achieve the maximum effect in this study was 75.5
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
- …
