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Dietetics, Nutrition and Biological Sciences

Permanent URI for this collectionhttps://eresearch.qmu.ac.uk/handle/20.500.12289/23

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Author: search.filters.author.Fyfe, LornaStart date: 2010

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    The effect of green-coffee-bean extract rich in chlorogenic acid on antioxidant status of healthy human volunteers
    (Cambridge University Press, 2010-01) Almoosawi, Suzana; Tsang, Catherine; Davidson, Isobel M; Fyfe, Lorna
    Several studies have linked consumption of green-coffee-bean extract (GCBE) rich in chlorogenic acid (CGA) with reduced blood pressure(Reference Watanabe, Arai and Mitsui1–Reference Ochiai, Jokura and Suzuki3). It is hypothesised that increased antioxidant activity could be one of the underlying mechanisms by which GCBE reduces blood pressure. To test this hypothesis a GCBE preparation rich in CGA was assessed by three extraction methods for antioxidant activity. In vivo antioxidant activity was also determined in a group of healthy volunteers. The phenolic content of GCBE, as determined by the Folin-Ciocalteu method, varied greatly between the ethanolic acidified water (0.2% (v/v) formic acid) and acetonitrile extract (acetonitrile–water containing 0.2% (v/v) formic acid; 50:50, v/v): 123 (sd 0.23), 131 (sd 0.66) and 211 (sd 0.51) mg gallic acid equivalents (GAE)/g extract respectively. Similar findings were observed with the Fe3+-reducing ability of plasma (FRAP) assay, wherein the acetonitrile extract exhibited a stronger Fe3+-reducing ability than the ethanolic extract (0.067 mmol/g extract v. 0.048 mmol/g extract). The 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) radical-scavenging activity of the ethanolic extract of GCBE was 70.4% at 50 μm as compared with ascorbic acid (86.1% inhibition at 50 μm) and GAE (82.2% at 50 μm). To examine in vivo antioxidant properties of GCBE thirteen healthy volunteers (age 36 (sd 11) years, BMI 28 (sd 2.5) kg/m2) consumed 200 mg GCBE containing 90 mg CGA twice daily for 2 weeks. In vivo antioxidant activity was determined using the Folin-Ciocalteu method and FRAP. There was a significant correlation between urinary polyphenols excretion as determined by the Folin-Ciocalteu method and FRAP (0.664, P<0.0001). However no significant increase in urinary antioxidant activity was observed (total phenolics: 173.2 (sd 137.8) mg GAE/g creatinine v. 175.20 (sd 115.7) mg GAE/g creatinine, P>0.05; FRAP: 2.07 (sd 0.9) mmol Fe2+/g creatinine v. 1.56 (sd 0.7) mmol Fe2+/g creatinine, P>0.05). Systolic blood pressure decreased from 119 (sd 10.5) to 114 (sd 9.1) mmHg (P=0.05) following the 2-week treatment. In conclusion, green coffee bean extract has a high antioxidant activity. However, no changes in antioxidant activity are observed in urine. This finding is consistent with previous findings of poor antioxidant activity of hippuric acid, the main urinary metabolite of chlorogenic acid(Reference Olthof, Hollman and Buijsman4). Further research is required to identify the mechanism(s) of reduction in blood pressure. The antioxidant activity of plasma should also be determined.
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    Comparing Manuka and other medical honeys as adjunct to antibiotic therapy against facultative anaerobes
    (Penerbit UKM, 2022-05) Sievers, Justus Thomas Obiajulu; Moffat, Emily; Yusuf, Khadijah; Sarwar, Nabaa; Bowolaksono, Anom; Fyfe, Lorna
    The development of antibiotic resistance in pathogenic bacteria has created a push for new treatments, with honeys (especially Manuka) becoming a common focus due to their strong antimicrobial action. However, alternatives to Manuka are necessary, as its production is vulnerable. Additionally, research is lacking on how honey affect facultative anaerobic bacteria grown in anaerobic conditions and how honey and antibiotics interact in these conditions. In order to understand these interactions and find novel honey candidates, we investigated the antibacterial effects of four honeys (two Manuka, one Chilean and one ‘Santa Cruz’ honeydew honey) against Staphylococcus aureus and Pseudomonas aeruginosa grown aerobically and anaerobically in broth cultures, and how the honeys affected the action of common antibiotics against these bacteria using agar diffusion assays. We found all honeys to be highly effective at 75% honey, with no significant differences between honeys, showing that other honeys were suitable alternatives to Manuka at such high concentrations. At 20%, oxygen availability and bacterial species impacted the effectiveness of honeys as Santa Cruz honey was most effective aerobically but failed anaerobically, while Manuka honeys were effective against S. aureus but not P. aeruginosa in both conditions, and Chilean honey was ineffective against all samples. The addition of honey increased bacterial sensitivity to antibiotics in some cases, varying with aerobic conditions. The antibacterial activity of the honeys, and differences in conditions whether aerobically or anaerobically, were not correlated with pH, antioxidant capacity or total phenolic count. Since in all cases honeys were either beneficial or of no effect, these results supported the use of honey as adjunct to antibiotic therapy in scenarios such as on bandages, with honeys other than Manuka also being worth consideration.
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    Honey combination therapies for skin and wound infections: A systematic review of the literature
    (Dove Medical Press, 2020-11-24) McLoone, Pauline; Tabys, Dina; Fyfe, Lorna
    Topical application of medical grade honey is recommended for the clinical management of wound infections. The suitability of honey as a wound healing agent is largely due to its antibacterial activity, immune modulatory properties, and biocompatibility. Despite the usefulness of honey in wound healing, chronic wound infections continue to be a global problem requiring new and improved therapeutic interventions. Several recent studies have investigated the effects of combining honey with other therapies or agents with the aim of finding more efficacious treatments. In this systematic review, the database PubMed was used to carry out a search of the scientific literature on the combined effects of honey and other therapies on antimicrobial activity and wound and skin healing. The search revealed that synergistic or additive antimicrobial effects were observed in vitro when honey was combined with antibiotics, bacteriophages, antimicrobial peptides, natural agents e.g. ginger or propolis and other treatment approaches such as the use of chitosan hydrogel. Outcomes depended on the type of honey, the combining agent or treatment and the microbial species or strain. Improved wound healing was also observed in vivo in mice when honey was combined with laser therapy or bacteriophage therapy. More clinical studies in humans are required to fully understand the effectiveness of honey combination therapies for the treatment of skin and wound infections.
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    Inhibition and changes in antibiotic sensitivity of bacteria cultured aerobically and anaerobically in four different medicinal honeys
    (eScientific, 2020-03-27) Klein, Juan-Pablo; Graves-Morris, Katherine; Coyle, Shirley; Fyfe, Lorna
    The growing prevalence of bacterial antibiotic resistance has led to a rediscovery of the antimicrobial properties of honey. This study investigated the antibacterial activity in aerobic and anaerobic conditions, the effect on bacterial antibiotic sensitivity, and the composition of four medical-grade honeys Medihoney®, Comvita® Antibacterial Wound Gel™, Revamil® gel, and Surgihoney™RO®.A broth assay was used to assess the antibacterial activity of the honeys against Staphylococcus aureus and Pseudomonas aeruginosa in aerobic and anaerobic conditions. A disk diffusion test was used to investigate the effect of exposure to a subinhibitory concentration of the honeys to the sensitivity of bacteria to a range of antibiotics. The composition of each honey was characterised by measuring: sugar content, pH, hydrogen peroxide activity, total polyphenolic content and antioxidant capacity.The honeys differed widely in antibacterial activity. Medihoney® was the most effective reducing the growth of both bacteria to < 1 compared to 9 log10 cfu/mL in the growth controls at all tested concentrations. Revamil® gel was the least active of the honeys only having a negligible effect on bacterial growth at the 25% honey concentration. All honeys were equally or more active in anaerobic conditions than in aerobic conditions. The polyphenolic content may influence the activity of honey. Various honey-antibiotic combinations were identified that enhanced antibiotic sensitivity in bacteria. More research is needed to clarify the role of polyphenols in honey activity and further explore the potential synergies between the honeys and antibiotics.
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    Honey: A realistic antimicrobial for disorders of the skin
    (2015-01-19) McLoone, Pauline; Warnock, Mary; Fyfe, Lorna
    Resistance of pathogenic micro-organisms to antibiotics is a serious global health concern. In this review, research investigating the antimicrobial properties of honeys from around the world, against skin relevant microbes is evaluated. A plethora of in vitro studies have revealed that honeys from all over the world have potent microbicidal activity against dermatologically important microbes. Moreover, in vitro studies have shown that honey can reduce microbial pathogenicity as well as reverse anti-microbial resistance. Studies investigating the antimicrobial properties of honey in vivo have been more controversial. It is evident that innovative research is required to exploit the anti-microbial properties of honey for clinical use and to determine the efficacy of honey in the treatment of a range of skin disorders with a microbiological aetiology
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    A Randomised Double Blind Placebo Controlled Trial of a Nucleotide-Containing Supplement Nucell on Symptoms of Participants with the Common Cold - A Pilot Study
    (ECronicon, 2016-05-20) Davidson, Isobel; Fyfe, Lorna
    Objectives: To ascertain whether a nucleotide containing nutritional supplement Nucell attenuates self-reported symptoms of the common cold. Design: A randomised controlled trial. Setting: A University. Participants: Participants with self-reported symptoms of the common cold but otherwise healthy individuals. Intervention: Nucell capsules containing a yeast-based nucleotide preparation or placebo were provided over a 28 day period. Outcome Measures: Subjective ratings of symptoms were recorded by self-administered questionnaires using a nine-point scale. Salivary IgA concentrations were analysed from samples collected during the first 7 days and then at days 14,21 and 28 of supplementation. Total and white blood cell counts were also measured throughout the intervention. Results: Thirty-six participants completed the study. Nineteen received Nucell and 17 received the placebo. The mean age of participants was similar (29.8 + 2.5 in Nucell group v 30.7 + 2.7 in control group) and the time participants had been suffering from cold-related symptoms was not significantly different in each treatment group (2.5 + 0.40 days in Nucell v 2.9 + 0.47 days in control group). Severity of self-reported symptoms was significantly attenuated in the Nucell treated group in the first week of supplementation for questions asked with respect to taste, painful sinuses and earache (p< 0.05). Supplementation with Nucell did not adversely affect total or differential white blood counts. Conclusion: These results suggest that Nucell supplementation administered as a treatment for cold-related symptoms may reduce the severity of specific symptoms particularly in the early infective phase. In conclusion, Nucell supplementation may provide subjective relief of some cold-related symptoms and may be of significant benefit administered as a treatment in participants where sinus pain, earache and diminished taste are common symptoms.
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    Influence of Subinhibitory Concentrations of Honey on Toxic Shock Syndrome Toxin -1 (TSST-1) Production by Two Strains of Staphylococcus Aureus
    (Horizon Research Publishing, 2015-05) Okoro, P.; Coyle, S.; Fyfe, Lorna
    Antibiotic resistant bacteria are a worldwide health concern and it is essential to develop new antimicrobial agents to kill these bacteria and to reduce the use of antibiotics. Staphyloccus aureus (S.aureus) an important medical pathogen is responsible for many wound infections and up to 25% of all strains produce the toxic shock syndrome toxin (TSST-1) which stimulates the release of inflammatory cytokines which cause fever and shock. Here we report on the inhibition of two penicillin resistant TSST-1 producing strains of S.aureus by seven different honeys. Bacterial growth was reduced after 24 hours at 37oC, from 10.0 log 10 in the TSB growth control to less than 1.0 log 10 in Highland, Chilean and Manuka honey. TSST-1 production was reduced from 256ng/ml in the TSB growth control to less than 30 ng/ml in sub inhibitory concentrations of all honeys.
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    Anti-microbial activity and composition of Manuka and Portobello honey
    (John Wiley & Sons, Ltd, 2013-08) Schneider, M.; Coyle, S.; Warnock, Mary; Gow, Iain F.; Fyfe, Lorna
    Recently renewed interest in the therapeutic properties of honey has led to the search for new antimicrobial honeys. This study was undertaken to assess the antimicrobial activity and composition of a locally produced Portobello honey (PBH) on three bacteria known to infect wounds. Manuka honey (MH) was used for comparative purposes. Broth culture and agar disc diffusion assays were used to investigate the antimicrobial properties of honey. The honeys were tested at four concentrations: 75%, 50%, 10% and 1% (v/v) and compared with an untreated control. The composition of honey was determined by measuring: polyphenol content by Folin Ciocalteau method, antioxidant capacity by ferric ion reducing power assay, hydrogen peroxide (H2O2) by catalase test, pH and sugar content by pH strips and refractometer, respectively. Both honeys at 75% and 50% inhibited the majority of the three bacteria tested. 10% PBH exhibited antimicrobial activity to the lesser extent than 10% MH. The difference was very significant (p ≤ 0.001). Both honeys were acidic with pH 4, and both produced H2O2. The sugar content of PBH was higher than MH, but the difference was not significant. The MH had significantly higher levels of the polyphenols and antioxidant activity than PBH. Copyright © 2012 John Wiley & Sons, Ltd.
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    The Roles of Opioid Receptors and Agonists in Health and Disease Conditions
    (Maxwell Scientific Organization,, 2011-04-30) Ibegbu, A. O.; Mullaney, I.; Fyfe, Lorna; McBean, Douglas
    Opioid receptors are found in the Central Nervous System (CNS) and are classified as mu (µ), kappa (κ), delta (δ) and sigma (σ) opioid receptors. Opioid receptors belong to the large family of G Protein Coupled Receptors (GPCRs), and have diverse and important physiological roles. The aim of the present review is to discuss the roles played by opioid receptors, their agonists and antagonists in health and disease conditions. Opioid receptors are not uniformly distributed in the CNS and are found in areas concerned with pain, with the highest concentration in the cerebral cortex, followed by the amygdala, septum, thalamus, hypothalamus, midbrain and spinal cord. Activated delta opioid receptors are coupled to Gi1 while activated mu opioid receptors are coupled to Gi3 in neuroblastoma cells. Mu opioid receptors are activated by mu receptor agonists and are coupled through the Gi1 and GoA. Both mu and kappa opioid receptors are coupled via both Gi and Gz and opioid receptors are important targets for thousands of pharmacological agents. GPCRs typically require activation by agonists for their signalling activity to be initiated but some of the GPCRs may display basal or spontaneous signalling activity in the absence of an agonist. The stimulation of these receptors triggers analgesic effects and affects the function of the nervous system, gastrointestinal tract and other body systems. Hundreds of analogs of opioid peptides have been synthesized in an effort to make the compounds more active, selective, and resistant to biodegradation than the endogenous ligands. All these modifications resulted in obtaining very selective agonists and antagonists with high affinity at mu-, delta-, and kappa-opioid receptors, which are useful in further studies on the pharmacology of opioid receptors in a mammalian organism.