686 research outputs found

    Effects of carbohydrate and green tea co-ingestion on performance, metabolism and hormone during cycling exercise

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    It has been known that carbohydrate intake during exercise can improve athletic performance, and caffeine can extend exercise endurance. Green tea containing caffeine and various polyphenols has been suggested beneficial to athletes due to anti-oxidative and anti-inflammatory effects. Therefore, this study investigated the influence of carbohydrate and green tea co-ingestion on the performance, metabolism and hormone during high-intensity road cycling exercise. Nine well-trained male cyclists, aged 17.8 ± 1.0 yr, participated this acute-treatment, double-blind, crossover study that included 6.4-km cycling time trial. Participants ingested carbohydrate (240 mg/kg body mass fructose and 120 mg/kg body mass glucose) without (CHO group) and with green tea (TEA group) (22 mg/kg body mass catechins and 6 mg/kg body mass caffeine) during cycling exercise. Three blood samples were collected before exercise, immediately after exercise and at 15 h after exercise. It was found that the improved performance caused by co-ingestion of carbohydrate and green tea was meaningful to the athletes during competition. The percentage of neutrophil in blood was much higher in CHO group than TEA group. The blood sugar level after exercise was significantly lower by 20% than pre-exercise in TEA group, whereas no significant change was found in CHO group. The lactate level was significantly increased to 2.55 and 3.05 mM after exercise in CHO and TEA group, respectively. In addition, significant increase of creatine kinase activity was found in CHO group, but not in TEA group. The blood testosterone level was significantly decreased by 50% in CHO group, but only 11% decrease in TEA group. These major results suggest that dual-supplementation of carbohydrate and green tea not only elevated exogenous glucose oxidation but also compromised inflammation by decreasing the level of muscle damage during intensive exercise. Moreover, the slightly decreased testosterone level represents a positive adaptation to high exercise loading. This information would provide coaches and athletes to choose nutritional supplements

    Effects of an acute bout of light-intensity walking on sleep in older women with sleep impairment: A randomized controlled trial

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    Study objective: This study aimed to explore the effects of a single bout of light-intensity walking on sleep in older women with mild sleep impairment. Methods: A total of 40 women aged 55 years or above with mild sleep impairment were randomized to either a treadmill-walking session for 50 mins or a quiet-rest control. All participants completed the study (mean age: 60.4±4.7). Sleep quality was assessed by ActiGraph for 2 nights before (pre-test) and 2 nights after exercise (post-test). A mixed-design analysis of variance was used with group as the between-subjects factor and time point as the within-subjects factor. Results: No significant group difference on demographic variables, body mass index, physical and mental status, and eight sleep parameters were observed at baseline. Significant group-time interactions existed for sleep latency (p<0.001) and sleep efficiency (p=0.025). After the intervention, the walking group reduced sleep latency by 3.3 minutes (p=0.001) and also had greater sleep efficiency (increase 3.8%, p=0.008), but no significant change was found in the control group. No significant group-time interactions were present for the other six sleep parameters (activity counts, total sleep time, wake after sleep onset, number and length of awakenings, or time in bed). Conclusion: A single session of light-intensity walking led to a modest reduction in sleep latency and improvement of sleep efficiency in older women with mild sleep impairment

    Discovery of Furanoquinone Derivatives as a Novel Class of DNA Polymerase and Gyrase Inhibitors for MRSA Eradication in Cutaneous Infection

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    Methicillin-resistant Staphylococcus aureus (MRSA) is the primary microbe responsible for skin infections that are particularly difficult to eradicate. This study sought to inhibit planktonic and biofilm MRSA using furanoquinone-derived compounds containing imine moiety. A total of 19 furanoquinone analogs were designed, synthesized, and assessed for anti-MRSA potency. Among 19 compounds, (Z)-4-(hydroxyimino)naphtho[1,2-b]furan-5(4H)-one (HNF) and (Z)-4-(acetoxyimino)naphtho[1,2-b]furan-5(4H)-one (ANF) showed antibacterial activity superior to the others based on an agar diffusion assay. HNF and ANF exerted a bactericidal effect with a minimum inhibitory concentration (MIC) of 9.7 ∼ 19.5 and 2.4 ∼ 9.7 μg/ml, respectively. Both compounds were able to reduce the MRSA count by 1,000-fold in biofilm as compared to the control. In vivo efficacy was evaluated using a mouse model of skin infection. Topical application of lead compounds significantly suppressed abscess occurrence and the MRSA burden, and also ameliorated the skin-barrier function. The biochemical assay indicated the compounds’ inhibition of DNA polymerase and gyrase. In silico docking revealed a favorable interaction of the compounds with DNA polymerase and gyrase although the binding was not very strong. The total DNA analysis and proteomic data suggested a greater impairment of some proteins by HNF than ANF. In general, HNF and ANF were similarly potent in MRSA inhibition in vitro and in vivo. The findings demonstrated that there was room for structural modification of furanoquinone compounds that could be used to identify anti-MRSA agent candidates

    Different Influences on Tacrolimus Pharmacokinetics by Coadministrations of Zhi Ke and Zhi Shi in Rats

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    Tacrolimus, an immunosuppressant with narrow therapeutic window, has been used widely in transplant patients. Grapefruit juice and pomelo have been reported to increase the blood levels of tacrolimus. Zhi Ke and Zhi Shi, the ripe peels and unripe fruits of Citrus aurantium which is chemotaxonomically related to grapefruit and pomelo, are in wide use in clinical Chinese medicine. To investigate the possible interaction of these two Citrus herbs with tacrolimus, male Sprague-Dawley rats were orally given tacrolimus (1.5 mg/kg) with and without Zhi Ke and Zhi Shi decoctions in a cross-over design. Blood samples were withdrawn via cardiopuncture at specific time and quantitated by a microparticle enzyme immunoassay. In addition, to explore the mechanism of interaction, LS 180 cell line was used for the transport study of rhodamine 123, a typical substrate of P-glycoprotein (P-gp). The results showed that Zhi Shi significantly decreased the Cmax and AUC0−t of tacrolimus by 72.4% and 72.0%, respectively, whereas Zhi Ke did not affect tacrolimus pharmacokinetics. LS 180 cell line study indicated that Zhi Shi increased the efflux activity of P-gp, enabling us to explain the decreased oral bioavailability of tacrolimus caused by Zhi Shi. Hence, we suggest that Zhi Shi be contraindicated for transplant patients treated with tacrolimus to reduce the risk of allograft rejection

    Lignocellulosic saccharification by a newly isolated bacterium, Ruminiclostridium thermocellum M3 and cellular cellulase activities for high ratio of glucose to cellobiose

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    Background: Lignocellulosic biomass is one of earth's most abundant resources, and it has great potential for biofuel production because it is renewable and has carbon-neutral characteristics. Lignocellulose is mainly composed of carbohydrate polymers (cellulose and hemicellulose), which contain approximately 75 % fermentable sugars for biofuel fermentation. However, saccharification by cellulases is always the main bottleneck for commercialization. Compared with the enzyme systems of fungi, bacteria have evolved distinct systems to directly degrade lignocellulose. However, most reported bacterial saccharification is not efficient enough without help from additional β-glucosidases. Thus, to enhance the economic feasibility of using lignocellulosic biomass for biofuel production, it will be extremely important to develop a novel bacterial saccharification system that does not require the addition of β-glucosidases. Results: In this study, a new thermophilic bacterium named Ruminiclostridium thermocellum M3, which could directly saccharify lignocellulosic biomass, was isolated from horse manure. The results showed that R. thermocellum M3 can grow at 60 °C on a variety of carbon polymers, including microcrystalline cellulose, filter paper, and xylan. Upon utilization of these substrates, R. thermocellum M3 achieved an oligosaccharide yield of 481.5 ± 16.0 mg/g Avicel, and a cellular β-glucosidase activity of up to 0.38 U/mL, which is accompanied by a high proportion (approximately 97 %) of glucose during the saccharification. R. thermocellum M3 also showed potential in degrading natural lignocellulosic biomass, without additional pretreatment, to oligosaccharides, and the oligosaccharide yields using poplar sawdust, corn cobs, rice straw, and cornstalks were 52.7 ± 2.77, 77.8 ± 5.9, 89.4 ± 9.3, and 107.8 ± 5.88 mg/g, respectively. Conclusions: The newly isolated strain R. thermocellum M3 degraded lignocellulose and accumulated oligosaccharides. R. thermocellum M3 saccharified lignocellulosic feedstock without the need to add β-glucosidases or control the pH, and the high proportion of glucose production distinguishes it from all other known monocultures of cellulolytic bacteria. R. thermocellum M3 is a potential candidate for lignocellulose saccharification, and it is a valuable choice for the refinement of bioproducts

    Pterostilbene, a Methoxylated Resveratrol Derivative, Efficiently Eradicates Planktonic, Biofilm, and Intracellular MRSA by Topical Application

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    Pterostilbene is a methoxylated derivative of resveratrol originated from natural sources. We investigated the antibacterial activity of pterostilbene against drug-resistant Staphylococcus aureus and the feasibility of using it to treat cutaneous bacteria. The antimicrobial effect was evaluated using an in vitro culture model and an in vivo mouse model of cutaneous infection. The minimum inhibitory concentration (MIC) assay demonstrated a superior biocidal activity of pterostilbene compared to resveratrol (8~16-fold) against methicillin-resistant S. aureus (MRSA) and clinically isolated vancomycin-intermediate S. aureus (VISA). Pterostilbene was found to reduce MRSA biofilm thickness from 18 to 10 μm as detected by confocal microscopy. Pterostilbene showed minimal toxicity to THP-1 cells and was readily engulfed by the macrophages, facilitating the eradication of intracellular MRSA. Pterostilbene exhibited increased skin absorption over resveratrol by 6-fold. Topical pterostilbene application improved the abscess formation produced by MRSA by reducing the bacterial burden and ameliorating the skin architecture. The potent anti-MRSA capability of pterostilbene was related to bacterial membrane leakage, chaperone protein downregulation, and ribosomal protein upregulation. This mechanism of action was different from that of resveratrol according to proteomic analysis and molecular docking. Pterostilbene has the potential to serve as a novel class of topically applied agents for treating MRSA infection in the skin while demonstrating less toxicity to mammalian cells

    The Influence of Ingestion Glucose Beverage before Graded Exercise to Exhaustion on Saliva IgA Concentration in Hypoxia and Normoxia Environment

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    In addition to exercise, hypoxia environment might induce higher immune stress. The present study was to investigate the ingestion of glucose before graded exercise to exhaustion in hypoxia environment on immune responses. Eight healthy college students
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