Search results for "Native"
showing 10 items of 1727 documents
Combinations of discourse markers with repairs and repetitions in English, French and Spanish
2020
Abstract Discourse markers have a central role in planning and repairing processes of speech production. They relate with fluency and disfluency phenomena such as pauses, repetitions and reformulations. Their polyfunctionality is challenging and few form-function mappings are stable cross-linguistically. This study combines a functional and a structural approach to discourse markers and their combination with and within repetitions and self-repairs in native English, French and Spanish, in order to establish the inter-relation between these three fluency-related devices and to find potentially universal patterns of use. Qualitative coding and quantitative analyses of categories of markers a…
Polyoxygenated Cyclohexenes and Other Constituents of Cleistochlamys kirkii Leaves.
2016
Thirteen new metabolites, including the polyoxygenated cyclohexene derivatives cleistodiendiol (1), cleistodienol B (3), cleistenechlorohydrins A (4) and B (5), cleistenediols A-F (6-11), cleistenonal (12), and the butenolide cleistanolate (13), 2,5-dihydroxybenzyl benzoate (cleistophenolide, 14), and eight known compounds (2, 15-21) were isolated from a MeOH extract of the leaves of Cleistochlamys kirkii. The purified metabolites were identified by NMR spectroscopic and mass spectrometric analyses, whereas the absolute configurations of compounds 1, 17, and 19 were established by single-crystal X-ray diffraction. The configuration of the exocyclic double bond of compound 2 was revised base…
Pharmacogenomic and molecular docking studies on the cytotoxicity of the natural steroid wortmannin against multidrug-resistant tumor cells
2014
Wortmannin is a cytotoxic compound derived from the endophytic fungi Fusarium oxysporum, Penicillium wortmannii and Penicillium funiculosum that occurs in many plants, including medicinal herbs. The rationale to develop novel anticancer drugs is the frequent development of tumor resistance to the existing antineoplasic agents. Therefore, it is mandatory to analyze resistance mechanisms of novel drug candidates such as wortmannin as well to bring effective drugs into the clinic that have the potential to bypass or overcome resistance to established drugs and to substantially increase life span of cancer patients. In the present project, we found that P-glycoprotein-overexpressing tumor cells…
Rhodiola rosea Impairs Acquisition and Expression of Conditioned Place Preference Induced by Cocaine
2013
A novel approach to the treatment of adverse effects of drugs of abuse is one which makes use of natural products. The present study investigated the effect ofRhodiola roseaL. hydroalcoholic extract (RHO) on cocaine-induced hyperactivity and conditioned place preference (CPP) in mice. In a first experiment, mice received RHO (15, 20 or 25 mg/kg, IG), cocaine (25 mg/kg, i.p.) (COC), or a combination of both drugs (COC + RHO15, COC + RHO20, and COC + RHO25), and their locomotor activity was evaluated. In a second experiment, the effects of RHO on the acquisition, expression, and reinstatement of cocaine CPP (induced by drug priming or social defeat stress) were evaluated. RHO alone did not in…
Role of Levo-tetrahydropalmatine and its metabolites for management of chronic pain and opioid use disorders.
2021
Abstract Background Opioids have been prescribed to reduce suffering from pain and to enhance quality of life. Due to the addictive potential and the lack of other effective alternatives to treat severe acute and chronic pains, opioids remain a serious public health issue. While, opioids directly influence the drug-seeking behavior, tolerance and withdrawal processes, through neuroadaptation, the brain's endogenous opioid system also adapts in the presence of chronic pain and could contribute to the difficulty of treatment. Despite the seemingly obvious interaction between the presence of pain and opioid-abuse, little is known about the underlying mechanisms in the brain. Purpose To review …
Selected Secondary Plant Metabolites for Cancer Therapy
2015
Secondary plant metabolites reveal numerous biological activities making them attractive as resource for drug development of human diseases. As the majority of cancer drugs clinically established during the past half century is derived from nature, cancer researchers worldwide try to identify novel natural products as lead compounds for cancer therapy. Natural products are considered as promising cancer therapeutics, either as single agents or in combination protocols, to enhance the antitumor activity of additional therapeutic modalities. Most natural compounds exert pleotrophic effects and modulate various signal transduction pathways. A better understanding of the complex mechanisms of a…
Differential interactions of the broad spectrum drugs artemisinin, dihydroartemisinin and artesunate with serum albumin
2013
Artemisinin is a drug, widely used in malaria treatment. As the binding affinity of artemisinin and its derivatives dihydroartemisinin and artesunate to blood serum proteins might influence the effectiveness of the drug, binding of artemisinin and derivatives to serum albumin was studied under near physiological conditions. Binding kinetics indicate a simple, single-step association process for all artemisinin derivatives. The determined changes in enthalpy and entropy upon drug binding clearly indicate that hydrophobic forces are most important for artemisinin and dihydroartemisinin binding, whereas binding of artesunate is governed by both hydrophilic and hydrophobic forces. Key residues,…
Patterns and trends in scientific research on generic drugs
2016
[Purpose]: The purpose of this study to investigate the evolution and current status of peer-reviewed publications concerning generic drugs during the past few decades. [Methods]: Scientific articles about generic drugs published until 2012 were retrieved through the PubMed/MEDLINE database, and a content analysis was performed. [Findings]: Our study revealed an increasing number of publications on generics since 1984. Statins, antiretroviral therapies, and antiepileptics, followed by immunosuppressants and antithrombotic agents, were the most common therapeutic drug categories. [Implications]: Almost 60% of the generics detailed in studies indexed in MEDLINE were acting on the cardiovascul…
Adverse drug reactions in some African herbal medicine: literature review and stakeholders’ interview
2014
International audience; Background: In view of the large consumption of herbal medicine in Africa countries, it is likely that many adverse drugs reactions go unrecorded with either patients failing to present to health services, or no pharmacovigilance analysis being made, or the analysis not being reported centrally. This problem is of interest especially for those who are working in the general area of adverse drug reactions or stakeholders in the domain of herbal medicine for considering safety issues. Methods: We are particularly interested in the way that the use of very wellknown and highly valued plants is linked to the observation of adverse drug reactions in African countries. We …
Herbal Medicines: Boon or Bane for the Human Liver?
2016
Since ages, medicine is the most consistent companion of man. While in primeval time, disease was cured through natural preparations, onset of technology has made today’s formulations synthetic or nature derived. Across the ages, the plausibility of the “savior-turned-slayer” functionality of these drugs remained constant. With the increment in documentation, it becomes evident that many of the commonly used drugs are associated with toxicities. Thus, any drug, irrespective of its origin, needs to be thoroughly assessed. Rampant use of herbal drugs has often been a threat to human health owing to the scarcity in quality assessment. What needs to be understood is that everything natural is n…