46 research outputs found

    New cytotoxic fatty acid esters from the black coral, Antipathes dichotoma

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    Purpose: To isolate new fatty acid esters from Antipathes dichotoma and investigate their cytotoxic effects on HepG2, WI-38, VERO and MCF-7 cells.Methods: Antipathes dichotoma was collected using scuba at a depth of 10 to 20 m from the Red Sea, and the lyophilized sample (1500 g) was exhaustively extracted thrice using a mixture of chloroform and methanol (1:1, v/v). The extract was concentrated using a vacuum rotatory evaporator to obtain a brown gummy paste which was fractionated on a silica gel chromatography column and further purified using preparative thin layer chromatography (PTLC). The chemical structures of the newly isolated compounds were elucidated by spectroscopic methods such as infrared (IR), nuclear magnetic resonance (NMR) and mass spectrometry (MS). The cytotoxicity of the isolated compounds was examined in HepG2, WI 38, VERO and MCF-7 cell lines.Results: Three new aliphatic esters namely, (4Z, 7Z, 10Z, 13Z, 16Z)-1-hydroxynonadeca-4, 7, 10, 13, 16-pentaen-2-yl octanoate (1); (4Z, 7Z, 10Z, 13Z, 16Z)-1-hydroxynonadeca-4, 7, 10, 13, 16-pentaen-2- yl decanoate (2) and 1-hydroxynonadecan-2-yl-octanoate (3) were isolated from A. dichotoma. 1 and 2 displayed moderate cytotoxic activities against the examined cell lines with half-maximal inhibitory concentration (IC50) ranging from 30.1 to 43.0 μg/mL, while compound 3 exhibited poor anti-cancer activity.Conclusion: The results indicate that A. dichotoma is a reservoir of new compounds that have potential anticancer effects.Keywords: Red Sea, Black coral, Antipathes dichotoma, Esters, Cytotoxicit

    An extended information system success model for mobile learning usage in Saudi Arabia universities

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    The emergence of 4G networks allows m-learning to be attractive for educational systems. Mobile devices have the potential to enhance accessibility and efficiency distribution of educational materials and information. Developing countries, especially in the Middle East, lag behind as they face difficulties in the adoption and use of m-learning. Previous researches stated that the studies in the success of m-learning are still insufficient in developing countries, particularly in Saudi Arabia where the number of students involved in m-learning also constitutes low percentages. Nine factors that influence the success of m-learning are incorporated and evaluated into a research model. A quantitative approach was used, where questionnaires were sent to three universities in KSA. The contributing factors and the relationships between them were evaluated using a Structural Equation Modelling technique. The research revealed that information quality, user satisfaction (US), trust in technology, attitude, organisation support, trust in organisation, and the net benefits of m-learning positively influence m-learning usage. In addition, the results confirmed that user satisfaction is positively affected by system quality (SEQ), service quality (SQ), and net benefits (NB) of using (U) the system. The results also showed that there is a significant relationship between NB and US for m-learning technology. This study extends the previous research by providing a conceptual model for the successful execution of m-learning services in universities. This mediating effect of US explains the impact of independent variables (IQ, SEQ, SQ) on U. It also examined the mediating effect of U in explaining the influence of US on the NB using m-learning services. The findings of this study are valuable as input for the Ministry of Higher Education and practitioners concerned with successful m-learning services. This study constructed a new model to enhance the mobile learning usage among students in universities

    Cytotoxic effect of acetogenins and sesquiterpenes obtained from the Red alga Laurencia majuscula

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    Purpose: To evaluate the cytotoxicity of n-hexane extract and its metabolites obtained from the red alga, Laurencia majuscula, against three cancer cell lines HCT-116 (colon cancer), PC-3 (prostate cancer) and HepG2 (liver cancer) cells; and to identify the phytochemical compound(s) involved. Methods: Solvent extraction, thin layer chromatography, aluminum oxide column chromatography, and preparative thin layer chromatography (PTLC) were employed for isolating pure compounds from nhexane extract of Laurencia majuscula. Nuclear magnetic resonance (NMR) and mass spectrometry (MS) measurements were used for structural elucidation of the compounds. The cytotoxicity of the nonpolar extract and isolated compounds were evaluated against HCT, PC-3, and HepG2 cells using MTT assay, relative to the standard cytotoxic drug (cisplatin). Results: Three sesquiterpenes (1, 2 and 8), and five acetogenins (3-7) were isolated from the n-hexane extract. The n-hexane extract showed higher potent cytotoxic effect than sesquiterpenes and the acetogenins (3-7). Conclusion: These results indicate that the n-hexane extract of Laurencia majuscula exerts significant cytotoxicity against HCT-116, PC-3 and HepG2 cell lines, thus suggesting that the plant extract may be effective chemotherapeutic agents for the management of colon, postrate and liver cancer. Keywords: Red Sea alga, Rhodomelaceae, Polyketides, Terpenes, Anticance

    Antiproliferative effects of isoprenoids from Sarcophyton glaucum on breast cancer MCF-7 cells

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    Purpose: To evaluate the anticancer activity of isoprenoids of Sarcophyton glaucum on MCF-7 cells and to investigate the potential synergistic effect of doxorubicin.Methods: Isolation and purification of isoprenoids were performed by applying different planar chromatographic methods (CC and PTLC). Further analyses of the isoprenoids by nuclear magnetic resonance (NMR) and mass spectrometry (MS) carried out to identify the compounds. Sulforhodamine- B (SRB) assay was used to determine the cytotoxic activity of the compounds against the MCF-7 human cell line. Flow cytometric analysis was used to assess their impact on cell cycle of  MCF-7. Combination index (CI), when the compounds were combined with  doxorubicin, was calculated to determine possible synergism. The isoprenoid  compounds were also incubated at ¼ or ½ of their respective half-maximal  concentration (IC50) with equimolar concentrations of doxorubicin.Results: Four known isoprenoid derivatives (1-4) were identified as 10(14)-aromadendrene (1), sarcophinediol (2), ent-deoxysarcophine (3) and sarcotrocheliol acetate (4). It was observed that cells accumulated in pre-G phase as well. CI of compound 3 with doxorubicin was 0.67 and 0.79, respectively, at ¼ and ½ of IC50, indicating overt synergism. This was confirmed by re-assessing the cell cycle stages of MCF-7 cells.Conclusion: The results indicate that compound 3 exhibits promising cytotoxicity as well as synergism with doxorubicin in MCF-7 cells. This is attributed, at least partly, to its ability to generate intercellular apoptosis induction.Keywords: Sarcophyton glaucum, Combination index, Antiproliferation, Isoprenoidal derivatives, 10(14)-Aromadendrene,Sarcophinediol, Deoxysarcophine,  Sarcotrocheliol acetate, Doxorubici

    Utilizing biomass-based graphene oxide-polyaniline-Ag electrodes in microbial fuel cells to boost energy generation and heavy metal removal

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    Although regarded as environmentally stable, bioelectrochemical fuel cells or, microbial fuel cells (MFCs) continue to face challenges with sustaining electron transport. In response, we examined the performance of two graphene composite-based anode electrodes¿graphene oxide (GO) and GO-polymer-metal oxide (GO-PANI-Ag)¿prepared from biomass and used in MFCs. Over 7 days of operation, GO energy efficiency peaked at 1.022 mW/m2 and GO-PANI-Ag at 2.09 mW/m2. We also tested how well the MFCs could remove heavy metal ions from synthetic wastewater, a secondary application of MFCs that offers considerable benefits. Overall, GO-PANI-Ag had a higher removal rate than GO, with 78.10% removal of Pb(II) and 80.25% removal of Cd(II). Material characterizations, electrochemical testing, and microbial testing conducted to validate the anodes performance confirmed that using new materials as electrodes in MFCs can be an attractive approach to improve the electron transportation. When used with a natural organic substrate (e.g., sugar cane juice), they also present fewer challenges. We also optimized different parameters to confirm the efficiency of the MFCs under various operating conditions. Considering those results, we discuss some lingering challenges and potential possibilities for MFCs

    A Review on Cadmium and Lead Contamination: Sources, Fate, Mechanism, Health Effects and Remediation Methods

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    Cadmium and lead soil contamination is a widespread environmental problem that requires profound and sustainable solutions. These toxic elements can be naturally occurring on the Earth’s crust or from man-made origins. Cadmium and lead could accumulate and translocate in soil over the long term. Thus, their risk of entering the food chain is extremely elevated and their effects on the living organisms in the food web are of great concern. The main purpose of this review study is to emphasize the risk to human health of cadmium and lead as an environmental contaminant in soil and plants. Human exposure to cadmium and lead can cause severe illness; for instance, long-term exposure to cadmium can alter kidney health and cause dysfunction. Additionally, lead threatens the nervous system and causes countless diseases. Hence, the remediation of cadmium and lead from soil before they enter the food chain remains essential, and regular monitoring of their principal sources is crucially needed for a sustainable soil ecosystem

    Cutaneous leishmaniasis and co-morbid major depressive disorder: A systematic review with burden estimates

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    <div><p>Background</p><p>Major depressive disorder (MDD) associated with chronic neglected tropical diseases (NTDs) has been identified as a significant and overlooked contributor to overall disease burden. Cutaneous leishmaniasis (CL) is one of the most prevalent and stigmatising NTDs, with an incidence of around 1 million new cases of active CL infection annually. However, the characteristic residual scarring (inactive CL) following almost all cases of active CL has only recently been recognised as part of the CL disease spectrum due to its lasting psychosocial impact.</p><p>Methods and findings</p><p>We performed a multi-language systematic review of the psychosocial impact of active and inactive CL. We estimated inactive CL (iCL) prevalence for the first time using reported WHO active CL (aCL) incidence data that were adjusted for life expectancy and underreporting. We then quantified the disability (YLD) burden of co-morbid MDD in CL using MDD disability weights at three severity levels. Overall, we identified 29 studies of CL psychological impact from 5 WHO regions, representing 11 of the 50 highest burden countries for CL. We conservatively calculated the disability burden of co-morbid MDD in CL to be 1.9 million YLDs, which equalled the overall (DALY) disease burden (assuming no excess mortality in depressed CL patients). Thus, upon inclusion of co-morbid MDD alone in both active and inactive CL, the DALY burden was seven times higher than the latest 2016 Global Burden of Disease study estimates, which notably omitted both psychological impact and inactive CL.</p><p>Conclusions</p><p>Failure to include co-morbid MDD and the lasting sequelae of chronic NTDs, as exemplified by CL, leads to large underestimates of overall disease burden.</p></div

    Disrupted endothelial cell heterogeneity and network organization impair vascular function in prediabetic obesity

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    Background: Obesity is a major risk factor for diabetes and cardiovascular diseases such as hypertension, heart failure, and stroke. Impaired endothelial function occurs in the earliest stages of obesity and underlies vascular alterations that give rise to cardiovascular disease. However, the mechanisms that link weight gain to endothelial dysfunction are ill-defined. Increasing evidence suggests that endothelial cells are not a population of uniform cells but are highly heterogeneous and are organized as a communicating multicellular network that controls vascular function. Purpose: To investigate the hypothesis that disrupted endothelial heterogeneity and network-level organization contribute to impaired vascular reactivity in obesity. Methods and Results: To study obesity-related vascular function without complications associated with diabetes, a state of prediabetic obesity was induced in rats. Small artery diameter recordings confirmed nitric-oxide mediated vasodilator responses were dependent on increases in endothelial calcium levels and were impaired in obese animals. Single-photon imaging revealed a linear relationship between blood vessel relaxation and population-wide calcium responses. Obesity did not alter the slope of this relationship, but impaired calcium responses in the endothelial cell network. The network comprised structural and functional components. The structural architecture, a hexagonal lattice network of connected cells, was unchanged in obesity. The functional network contained sub-populations of clustered specialized agonist-sensing cells from which signals were communicated through the network. In obesity there were fewer but larger clusters of sensory cells and communication path lengths between clusters increased. Communication between neighboring cells was unaltered in obesity. Altered network organization resulted in impaired, population-level calcium signaling and deficient endothelial control of vascular tone. Conclusions: The distribution of cells in the endothelial network is critical in determining overall vascular response. Altered cell heterogeneity and arrangement in obesity decreases endothelial function and provides a novel framework for understanding compromised endothelial function in cardiovascular disease

    Community pharmacists’ perspectives on cardiovascular disease pharmaceutical care in the United Arab Emirates: a questionnaire survey-based analysis

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    Background: Community pharmacists play an intermediary role between prescribing physicians and patients in the United Arab Emirates (UAE) and thus are responsible for ensuring that patients receive optimal cardiovascular disease (CVD) pharmaceutical care.Methods: we used a cross-sectional design to assess the perceptions and practices of community pharmacists concerning pharmaceutical care for patients with CVD. A trained researcher visited randomly selected community pharmacies and used a structured questionnaire to conduct in-person interviews with pharmacists. The questionnaire collected demographic data and information on perceptions and practices regarding CVD pharmaceutical care.Results: Five hundred and fifty-one participants were recruited. The average participant age (mean ± SD) was 35 ± 2.7 years. The average perception score regarding CVD prevention and management was 75.6% (95% confidence interval [CI] 77.1%–74.2%), and the average practice score for CVD prevention and management was 87.1% (95% CI 76.5%–79.6%). Bivariate analysis revealed that gender (p = 0.001), education level (p &lt; 0.001), pharmacy position (p = 0.004), work experience (p &lt; 0.001), number of patients served per day (p &lt; 0.001) and being trained on CVD prevention and management (p &lt; 0.001) were significantly associated with perceptions about the prevention and management of CVD. Better practice scores were seen among older participants (OR 1.01; 95% CI 1–1.019), postgraduates (OR 1.77; 95% CI 1.66–1.89), workers at chain pharmacies (OR 1.24; 95% CI 1.11–1.39), pharmacists in charge (OR 1.22; 95% CI 1.01–1.47), pharmacists with &gt;10 years of experience (OR 11.3; 95% CI 6.01–15.62), pharmacists with 6–10 years of experience (OR 4.42; 95% CI 3.90–5) and pharmacists trained on CVD prevention and management (OR 1.29; 95% CI 1.15–1.46).Conclusion: Pharmacy practitioners working in community pharmacies in the UAE actively engage in delivering pharmaceutical care to patients, playing a role in CVD management and prevention. However, they showed low levels of involvement in other healthcare services, specifically in screening and measuring patients’ weight, glucose levels, and blood pressure, monitoring treatment responses, maintaining medical records, and reviewing medication refill histories. Activities such as educating patients, providing medication counseling, offering support for treatment adherence, and fostering collaborative relationships with other healthcare providers should be encouraged among UAE community pharmacists to ensure the provision of high-quality patient care
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