59 research outputs found
Evaluation of antimicrobial and antioxidant properties of leaves of Emex spinosa and fruits of Citrillus colocynthis from Saudi Arabia
The crude methanol extract of Citrullus colocynthis fruit and Emex spinosa leaves were examined for antimicrobial and antioxidant potentialities. The phytochemical analysis revealed presence of some bioactive principles, such as alkaloids, flavonoids and anthraquinones for E. spinosa and saponin, flavonoids, terpenoids and alkaloids for C. colocynthis. The antimicrobial activities were determined against seven bacterial strains (Proteus vulgaris NCTC 8196, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumonia ATCC 53651, Salmonella typhi NCTC 0650, Staphylococcus aureus ATCC 25923 and Bacillus cereus NCTC 8236) and one fungal strain (Candida albicans ATCC 7596). E. spinosa leaf methanol extract was most active against fungus, whileC. colocynthis fruit methanol extract was most active against bacteria, particularly E. coli ATCC 25922 and P. aeruginosa ATCC 27853. The antioxidant properties of extracts were investigated in vitro using1,1-diphenyl, 2-picryl hydrazyl (DPPH) radical scavenging assay and in vivo in rats using serological and enzymatic tests. Both plant extracts showed considerable antioxidant activities. The promising findings of this investigation could be used as a novel natural antimicrobial and antioxidant agents.Keywords: Emex spinosa, Citrillus colocynthis, antimicrobial, antioxidant activity.African Journal of Biotechnology Vol. 12(34), pp. 5308-531
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Consumer responses to the failure of self-service banking technology: moderating role of failure stability
Purpose: The purpose of this study is to investigate the impact of dissatisfaction and anger, driven by the failure of the self-service technology (SST) of banks, on customers' post-purchase behavioral reactions, such as complaints, negative word-of-mouth and supplier change. Stability of the failure is proposed to moderate these relationships.
Design/methodology/approach: The proposed research model was tested through data collected from an online survey of a Tunisian sample of 300 respondents, using the scenario method.
Findings: The study validates the positive impact of dissatisfaction on anger and negative word-of-mouth, as well as that of anger on complaint behavior and negative word-of-mouth. The relation between dissatisfaction and negative word-of-mouth is mediated by anger. When the failure is stable, dissatisfied users of the SST seek to enhance their negative word-of-mouth and supplier change. The results also show that the stability of the failure enhances the effect of anger on complaint behavior.
Practical implications: Banks should invest efforts to accelerate the recovery of services to reduce consumer dissatisfaction and anger, and prevent adverse behavioral outcomes. Further, they need to ensure that failures are not repeated, as failure stability activates some otherwise non-significant behavioral outcomes like supplier change.
Originality/value: Previous works have focused on the impact of dissatisfaction and negative emotions for interpersonal services, but very few have come to associate dissatisfaction, anger, complaint, negative word-of-mouth, and supplier change in an integrative framework for an SST failure
Zinc homeostasis and signaling in health and diseases: Zinc signaling
The essential trace element zinc (Zn) is widely required in cellular functions, and abnormal Zn homeostasis causes a variety of health problems that include growth retardation, immunodeficiency, hypogonadism, and neuronal and sensory dysfunctions. Zn homeostasis is regulated through Zn transporters, permeable channels, and metallothioneins. Recent studies highlight Zn’s dynamic activity and its role as a signaling mediator. Zn acts as an intracellular signaling molecule, capable of communicating between cells, converting extracellular stimuli to intracellular signals, and controlling intracellular events. We have proposed that intracellular Zn signaling falls into two classes, early and late Zn signaling. This review addresses recent findings regarding Zn signaling and its role in physiological processes and pathogenesis
NM23 proteins: innocent bystanders or local energy boosters for CFTR?
NM23 proteins NDPK-A and -B bind to the cystic fibrosis (CF) protein CFTR in different ways from kinases such as PKA, CK2 and AMPK or linkers to cell calcium such as calmodulin and annexins. NDPK-A (not -B) interacts with CFTR through reciprocal AMPK binding/control, whereas NDPK-B (not -A) binds directly to CFTR. NDPK-B can activate G proteins without ligand-receptor coupling, so perhaps NDPK-B's binding influences energy supply local to a nucleotide-binding site (NBD1) needed for CFTR to function. Curiously, CFTR (ABC-C7) is a member of the ATP-binding cassette (ABC) protein family that does not obey 'clan rules'; CFTR channels anions and is not a pump, regulates disparate processes, is itself regulated by multiple means and is so pleiotropic that it acts as a hub that orchestrates calcium signaling through its consorts such as calmodulin/annexins. Furthermore, its multiple partners make CFTR dance to different tunes in different cellular and subcellular locations as it recycles from the plasma membrane to endosomes. CFTR function in airway apical membranes is inhibited by smoking which has been dubbed 'acquired CF'. CFTR alone among family members possesses a trap for other proteins that it unfurls as a 'fish-net' and which bears consensus phosphorylation sites for many protein kinases, with PKA being the most canonical. Recently, the site of CFTR's commonest mutation has been proposed as a knock-in mutant that alters allosteric control of kinase CK2 by log orders of activity towards calmodulin and other substrates after CFTR fragmentation. This link from CK2 to calmodulin that binds the R region invokes molecular paths that control lumen formation, which is incomplete in the tracheas of some CF-affected babies. Thus, we are poised to understand the many roles of NDPK-A and -B in CFTR function and, especially lumen formation, which is defective in the gut and lungs of many CF babies
Phytochemical composition and antimicrobial activities of the essential oils and organic extracts from <it>pelargonium graveolens</it> growing in Tunisia
<p>Abstract</p> <p>Background</p> <p><it>Pelargonium graveolens</it> (<it>P. graveolens</it>) L. is an aromatic and medicinal plant belonging to the <it>geraniacea</it> family.</p> <p>Results</p> <p>The chemical compositions of the essential oil as well as the <it>in vitro</it> antimicrobial activities were investigated. The GC-MS analysis of the essential oil revealed 42 compounds. Linallol L, Citronellol, Geraniol, 6-Octen-1-ol, 3,7-dimethyl, formate and Selinene were identified as the major components. The tested oil and organic extracts exhibited a promising antimicrobial effect against a panel of microorganisms with diameter inhibition zones ranging from 12 to 34 mm and MIC<sub>s</sub> values from 0.039 to10 mg/ml. The investigation of the phenolic content showed that EtOAc, MeOH and water extracts had the highest phenolic contents.</p> <p>Conclusion</p> <p>Overall, results presented here suggest that the essential oil and organic extracts of <it>P. graveolens</it> possesses antimicrobial and properties, and is therefore a potential source of active ingredients for food and pharmaceutical industry.</p
Short-term maximal performance, alertness, dietary intake, sleep pattern and mood states of physically active young men before, during and after Ramadan observance.
PurposeTo assess changes in short-term maximal performance, alertness, dietary intake, sleep pattern and mood states of physically active young men before (BR), during and after Ramadan observance.MethodsTwelve physically-active men (age: 21.9±2.4yrs, height:1.77±0.09m, body-mass: 72.6±7.8kg, exercising: ≥3h/week) performed the 5-jump and the digit-cancellation (alertness) tests 15-days BR, on the first (FR) and last 10-days of Ramadan (ER) and 10-days (AR10) and 20-days (AR20) after Ramadan. During each period, sleep pattern (Pittsburgh-Sleep-Quality-Index (PSQI)), mood states (Profile-of-Mood-States (POMS)) and dietary intake were recorded.ResultsNo significant changes in the 5-jump, digit-cancellation test and POMS parameters appeared during and after Ramadan relative to BR. However, the PSQI total score was lower during FR compared to AR10 (pConclusionRamadan had no-adverse effects on the 5-jump performance, alertness, or mood states in physically active young men. However, the sleep duration was shorter and the sleep quality was improved following compared to during Ramadan. The fractional intake of fat also increased at the expense of carbohydrate during Ramadan, and the protein intake was lower at the beginning of Ramadan than before, at the end of and after Ramadan
Dried Herbs as an Easy-to-Use and Cost-Effective Alternative to Essential Oils to Extend the Shelf Life of Sheep Lump Cheese
The objective of this research was to assess the effectiveness of three specific dried herbs (rosemary, thyme, and oregano) in combating microbial spoilage in sheep lump cheese. This was achieved by comparing them with a control group and cheeses treated with corresponding 1% essential oils (Rosmarinus officinalis, Origanum vulgare, Thymus vulgaris). All cheese samples were vacuum-sealed and stored at 4 °C for 15 days. Analysis of total viable counts of viable bacteria (TVC), coliform bacteria (CB), lactic acid bacteria (LAB), and microscopic filamentous fungi (MFF) was conducted on days 0, 5, 10, and 15. The results revealed that, at the end of the storage period, dried oregano-treated samples exhibited the lowest TVC count (5.80 log CFU/g), while dried rosemary-treated samples showed the lowest CB count (3.27 log CFU/g). Moreover, the lowest MFF count (2.40 log CFU/g) was observed in oregano essential oil-treated samples. Additionally, dried oregano-treated samples displayed the highest LAB count (4.49 log CFU/g) at the experiment’s conclusion. Furthermore, microorganism identification from sheep cheese was performed using MALDI-TOF MS Biotyper technology, revealing that the most frequently isolated bacteria were Citrobacter braakii and Hafnia alvei (Enterobacteriaceae family), along with Lacticaseibacillus paracasei (Lactobacillaceae family). In summary, all the natural substances examined exhibited inhibitory effects against the studied microorganisms, with oregano essential oil and dried oregano demonstrating the strongest inhibitory effects. This supports their potential use as cost-effective natural preservatives to extend the shelf life of sheep lump cheese
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