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Inhibition of uterine contractility by guanine-based purines in non-pregnant rats
Full text linkGrowing evidence pointed out that guanine-based purines are able to modulate smooth muscle contractile activity of blood
vessels and gastrointestinal tract. Since, so far, possible guanine-based purine modulation of uterine musculature is unknown,
the aim of the present study was to investigate in vitro, using organ bath technique, guanosine and guanine efects on
spontaneous uterine contraction, and uterine contraction induced by K+-depolarization and oxytocin in a non-pregnant rat.
Guanosine, but not guanine, reduced the amplitude of spontaneous contraction of the uterine muscle in a dose-dependent
manner. The inhibitory response was antagonized by S-(4-nitrobenzyl)-6-thioinosine (NBTI), a membrane nucleoside transporter inhibitor, but persisted in the presence of theophylline, a nonselective adenosine receptor antagonist, or propanolol,
β1/β2 adrenoreceptor antagonist or blockers of a nitrergic pathway. In addition, potassium channel blockers did not infuence
guanosine-induced efects. Guanosine was able to inhibit the external calcium (Ca2+) infux-induced contraction, but it did
not afect the contraction induced by high-KCl solution, indicating that guanosine does not interact with L-type voltage-gated
calcium channel. Guanosine prevented/reduced uterine contractions induced by oxytocin, even in the absence of external
calcium. In conclusion, guanosine is able to reduce both spontaneous and oxytocin-induced contractions of rat myometrium,
likely subsequently to its intracellular intake. The blockade of extracellular Ca2+ infux and reduction of Ca2+ release from
the intracellular store are the mechanisms involved in the guanosine-induced tocolytic efect
The chemical composition of the aerial parts essential oil of Ammi crinitum Guss. (Apiaceae) endemic of Sicily (Italy)
No full textAmmi L. is a small genus of economically important plants belonging to Apiaceae family that includes only six taxa. In the present study the chemical composition of the essential oil from aerial parts of Ammi crinitum Guss., a very rare plant, endemic of Sicily, was analyzed by GC-MS. No previously paper has been published on this species. The results showed the presence of large quantity of monoterpene hydrocarbons with sabinene (63.9%), as the most abundant component. Other metabolites present in good quantity were gamma-terpinene (8.0%), and 4-terpineol (3.7%). Based on the composition of the essential oil of all the other Ammi taxa, several considerations have been carried out
The ethnobotany, phytochemistry, and biological properties of genus Phagnalon (Asteraceae): a review
No full textThe genus Phagnalon Cass., included within the Asteraceae family, has a wide distribution, expanding from Macaronesia in the West to the Himalayas in the East, from S. France and N. Italy to Ethiopia and Arabian Peninsula. Various species of Phagnalon have been used in the popular medicine of several countries as medicinal herbs and food. This literature review, the first one of the Phagnalon genus, includes publications with the word 'Phagnalon', and considers the extracts and the single metabolites identified, characterized, and tested to evaluate their biological potential. The extracts and the secondary metabolites, have a varied application spectrum at a biological level, with antimicrobial, antioxidant, antidiabetic, antitumor, etc. properties having been reported. Unfortunately, in vitro tests have not always been accompanied by in vivo tests, and this is the major critical aspect that emerges from the study of the scientific aspects related to this genus
Anti-Inflammatory Potential of Brassicaceae-Derived Phytochemicals: In Vitro and In Vivo Evidence for a Putative Role in the Prevention and Treatment of IBD
Full text linkInflammatory bowel disease (IBD) is a group of intestinal disorders, of unknown etiology, characterized by chronic inflammation within the gut. They are gradually becoming critical because of the increasing incidence worldwide and improved diagnosis. Due to the important side effects observed during conventional therapy, natural bioactive components are now under intense investigation for the prevention and treatment of chronic illnesses. The Brassicaceae family comprises vegetables widely consumed all over the world. In recent decades, a growing body of literature has reported that extracts from the Brassicaceae family and their purified constituents have anti-inflammatory properties, which has generated interest from both the scientific community and clinicians. In this review, data from the literature are scrutinized and concisely presented demonstrating that Brassicaceae may have anti-IBD potential. The excellent biological activities of Brassicacea are widely attributable to their ability to regulate the levels of inflammatory and oxidant mediators, as well as their capacity for immunomodulatory regulation, maintenance of intestinal barrier integrity and intestinal flora balance. Possible future applications of bioactive-derived compounds from Brassicaceae for promoting intestinal health should be investigated
Essential oil of Sicilian Prangos ferulacea (L.) Lindl. and its major component, β−ocimen, affect contractility in rat small and large intestine
Full text linkEthnopharmacological relevance: Prangos ferulacea (L.) Lindl is an Apiaceae plant, widely used in traditional medicine. Recently, chemical composition and biological activities of its essential oil (Prangroil) have been reported, but there are no studies on possible effects on intestinal contractility. Aims of the study: We investigated the effects of essential oil Sicilian Prangoil on the contractility of rat small (duodenum) and large (colon) intestine and the related action mechanism. Materials and methods: Responses to Prangoil and to its major component β-ocimen in intestinal segments were assessed in vitro as changes in isometric tension. Results: Prangoil, induced in duodenum, depending upon doses, contraction and/or muscular relaxation. Instead, in colon Prangoil only reduced the phasic contractions and induced muscular relaxation. β-ocimen, in both segments, produced only reduction of the spontaneous contractions without affecting basal tone. Prangoil contractile effects were abolished by ω-conotoxin, neural N-type Ca2+ channels blocker, atropine, muscarinic receptor antagonist, neostigmine, acetylcholinesterase (AChE) inhibitor, suggesting that Prangoil-induced contraction would be the result of an increase in neuronal cholinergic activity. Prangoil and β-ocimen inhibitory effects were unaffected by ω-conotoxin, L-NAME, blocker of the NO synthase, ODQ, soluble guanylate cyclase inhibitor, excluding involvement of neurotransmitter release or NO synthesis in the inhibitory effects. Potassium channel blocker did not affect Prangoil or β-οcimen inhibitory responses. Prangoil or β-οcimen inhibited the Ca2+ and high-KCl solution -induced contractions and the Carbachol-induced contractions in calcium free solution. Conclusion: Prangoil affects the contractility of small and large intestine in rat, with regional differences, via potentiation of neural cholinergic activity, blockade of L-type voltage-gated calcium channel and reduction of Ca2+ release from the intracellular store. The Prangroil main components, β-ocimen, contributes to the inhibitory effects
Aging modifies receptor expression but not muscular contractile response to angiotensin II in rat jejunum
Full text link: The involvement of renin-angiotensin system in the modulation of gut motility and age-related changes in mRNA expression of angiotensin (Ang II) receptors (ATR) are well accepted. We aimed to characterize, in vitro, the contractile responses induced by Ang II, in jejunum from young (3-6 weeks old) and old rats (≥ 1 year old), to evaluate possible functional differences associated to changes in receptor expression. Mechanical responses to Ang II were examined in vitro as changes in isometric tension. ATR expression was assessed by qRT-PCR. Ang II induced a contractile effect, antagonized by losartan, AT1R antagonist, and increased by PD123319, AT2R antagonist, as well by neural blocker ω-conotoxin and by nitric oxide (NO) synthase inhibitor. No difference in the response was observed between young and old groups. AT1 receptor-mediated contractile response was decreased by U-73122, phospholipase C (PLC) inhibitor; or 2-aminoethoxy-diphenylborate (2-APB), inositol triphosphate (IP3) receptor inhibitor; or nifedipine, L-type calcium channel blocker. Age-related changes in the expression of both AT1 receptor subtypes, AT1a and AT1b, and of AT2 receptors were detected. In conclusion, Ang II modulates the spontaneous contractility of rat jejunum via postjunctional AT1 receptors, involving Ca2+ mobilization from intracellular stores, via PLC/IP3 pathway, and Ca2+ influx from extracellular space, via L-type channels. Prejunctional AT2 receptors would counteract AT1 receptor effects, via NO synthesis. The observed age-related differences in the expression of all AT receptor subtypes are not reflected in the muscular contractile response to Ang II
CHEMICAL CHARACTERIZATION AND IN VITRO AND IN VIVO EVALUATION OF ANTIOXIDANT PROPERTIES OF THREE SICILIAN ENDEMIC BRASSICA EXTRACTS
No full textIn recent years, scientific interest in natural compounds with antioxidant properties has significantly increased, largely due to the established link between oxidative stress and a range of chronic diseases. The prolonged use of conventional medications to manage chronic conditions associated with oxidative stress can lead to drug resistance and undesirable side effects, making natural alternatives an increasingly attractive option. Numerous studies have already highlighted the beneficial effects of Brassica species in both in vitro and in vivo models of oxidative stress. Sicily, known for its rich biodiversity, is home to more than 10 endemic species of this genus. Since plants have been shown to concentrate phytochemicals in response to environmental factors like salinity, solar radiation, and other stressors, we chose to explore wild Sicilian Brassica species. We hypothesized that, due to the unique climate of Sicily, these wild Brassica species may show specific phytochemical profiles offering distinct and potentially potent biological effects. The aim of this project was to evaluate the biological properties of endemic Brassica species through both in vitro and in vivo analyses. We selected three endemic species from different habitats: B. macrocarpa endemic to Favignana island, B. rupestris subsp. hispida endemic to Ficuzza wood, and B. tardarae endemic to Tardara gorges. methanolic extracts were prepared from the leaves, and the chemical composition was analysed by HPLC-MS/MS. The three Brassica species showed a similar chemical profile, containing significant amounts of glucosinolates and phenolic compounds. Notably, differences were observed in the sinapyl derivatives, which were found in higher concentrations in B. hispida compared to the other two species. Subsequently, their radical scavenging activities were evaluated using the diphenyl-2-picrylhydrazyl (DPPH) assay. All three Brassica species exhibited scavenging activities. In consideration of these results, we continued our investigation into the potential beneficial effects of these extracts in vitro, using the RAW 264.7 murine macrophage cell model. Assessing toxicity using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay we observed a reduction in cell viability were for B. hispida and B. tardarae, while B. macrocarpa proved to be safe at all concentrations tested. Moreover, using the Griess reaction we assessed in RAW 264.7 cells subjected to lipopolysaccharide (LPS)-induced oxidative stress the ability of the extracts to reduce nitric oxide (NO) production. At safe concentrations, B. hispida and B. tardarae were ineffective in reducing NO production, while B. macrocarpa successfully decreased NO levels. Real-time PCR analysis confirmed that B. macrocarpa treatment resulted in a reduction in NOS2 mRNA expression. Furthermore, in the 2’,7’-dichlorodihydrofluorescein diacetate (H2DCFDA) fluorescent probe assay, B. macrocarpa, once again, proved to be efficient in reducing the levels of ROS increased by exposure to LPS in a concentration-dependent manner.For in vivo studies, in the zebrafish (Danio rerio) embryo the toxicity, behaviour, and antioxidant properties of B. macrocarpa were evaluated. Zebrafish embryos were subjected to the acute toxicity test (FET). Throughout the 96-hour treatment period, no induced malformations were observed; however, changes in spontaneous movement and heart rate were noted. Behavioural tests did not indicate significant alterations in anxiety-like, aversion, or exploratory behaviours, and all groups displayed normal swimming patterns. Exposure to sub-lethal concentrations for 26 hours did not result in any noticeable changes in the key oxidative stress markers evaluated. By using copper sulphate (CuSO4)-induced oxidative stress model, zebrafish embryos pre-treated with B. macrocarpa extract showed a significant reduction in ROS and NO levels compared to the untreated group. The extract also modulated the activities of antioxidant enzymes, such as superoxide dismutase (SOD) and catalase (CAT). Additionally, lipid peroxidation and protein oxidation were reduced. However, the extract did not appear to reverse CuSO4-induced DNA damage. In conclusion, our data demonstrated that B. macrocarpa exhibited strong antioxidant properties, proving safe in the in vitro murine macrophage model, while in the FET test conducted on zebrafish embryo, showed to be safe up to 500 μg/mL. B. hispida and B. tardarae showed antioxidant effects solely in the DPPH assay and resulted to induce, in our model, cell toxicity at low concentration, hampering any further studies on their possible effects in our biological setting. Additional research is needed to further investigate their full potential
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
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