Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
Add more filters










Publication year range
1.
Eur J Nutr ; 63(3): 869-879, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38214710

ABSTRACT

PURPOSE: Shatavari is an understudied, widely available herbal supplement. It contains steroidal saponins and phytoestrogens. We previously showed that six weeks of shatavari supplementation improved handgrip strength and increased markers of myosin contractile function. Mechanistic insights into shatavari's actions are limited. Therefore, we performed proteomics on vastus lateralis (VL) samples that remained from our original study. METHODS: In a randomised double-blind trial, women (68.5 ± 6 years) ingested either placebo or shatavari (equivalent to 26,500 mg/d fresh weight) for six weeks. Tandem mass tag global proteomic analysis of VL samples was conducted (N = 7 shatavari, N = 5 placebo). Data were normalized to total peptides and scaled using a reference sample. Data were filtered using a 5% FDR. For each protein, the pre to post supplementation difference was expressed as log2 fold change. Welch's t tests with Benjamini-Hochberg corrections were performed for each protein. Pathway enrichment (PADOG, CAMERA) was interrogated in Reactome (v85). RESULTS: No individual protein was significantly different between supplementation conditions. Both PADOG and CAMERA indicated that pathways related to (1) Integrin/MAPK signalling, (2) metabolism/insulin secretion; (3) cell proliferation/senescence/DNA repair/cell death; (4) haemostasis/platelets/fibrin; (5) signal transduction; (6) neutrophil degranulation and (7) chemical synapse function were significantly upregulated. CAMERA indicated pathways related to translation/amino acid metabolism, viral infection, and muscle contraction were downregulated. CONCLUSION: Our analyses indicate that shatavari may support muscle adaptation responses to exercise. These data provide useful signposts for future investigation of shatavari's utility in conserving and enhancing musculoskeletal function in older age. TRIAL REGISTRATION: NCT05025917 30/08/21, retrospectively registered.


Subject(s)
Proteome , Resistance Training , Humans , Female , Proteome/metabolism , Proteomics , Hand Strength , Postmenopause , Muscle, Skeletal/metabolism , Dietary Supplements , Double-Blind Method , Muscle Strength
2.
Med Sci Sports Exerc ; 54(4): 609-621, 2022 04 01.
Article in English | MEDLINE | ID: mdl-34772901

ABSTRACT

INTRODUCTION: Montmorency cherry concentrate (MCC) supplementation enhances functional recovery from exercise, potentially due to antioxidant and anti-inflammatory effects. However, to date, supporting empirical evidence for these mechanistic hypotheses is reliant on indirect blood biomarkers. This study is the first to investigate functional recovery from exercise alongside molecular changes within the exercised muscle after MCC supplementation. METHODS: Ten participants completed two maximal unilateral eccentric knee extension trials after MCC or placebo (PLA) supplementation for 7 d before and 48 h after exercise. Knee extension maximum voluntary contractions, maximal isokinetic contractions, single leg jumps, and soreness measures were assessed before, immediately, 24 h, and 48 h after exercise. Venous blood and vastus lateralis muscle samples were collected at each time point. Plasma concentrations of interleukin-6, tumor necrosis factor alpha, C-reactive protein, creatine kinase, and phenolic acids were quantified. Intramuscular mRNA expressions of superoxide dismutase 1 (SOD1), SOD3, glutathione peroxidase 1 (GPX1), GPX3, GPX4, GPX7, catalase, and nuclear factor erythroid 2-related factor 2 and relative intramuscular protein expressions of SOD1, catalase, and GPX3 were quantified. RESULTS: MCC supplementation enhanced the recovery of normalized maximum voluntary contraction 1-s average compared with PLA (postexercise PLA, 59.5% ± 18.0%, vs MCC, 76.5% ± 13.9%; 24 h PLA, 69.8% ± 15.9%, vs MCC, 80.5% ± 15.3%; supplementation effect P = 0.024). MCC supplementation increased plasma hydroxybenzoic, hippuric, and vanillic acid concentrations (supplementation effect P = 0.028, P = 0.002, P = 0.003); SOD3, GPX3, GPX4, GPX7 (supplement effect P < 0.05), and GPX1 (interaction effect P = 0.017) gene expression; and GPX3 protein expression (supplementation effect P = 0.004) versus PLA. There were no significant differences between conditions for other outcome measures. CONCLUSIONS: MCC supplementation conserved isometric muscle strength and upregulated antioxidant gene and protein expression in parallel with increased phenolic acid concentrations.


Subject(s)
Prunus avium , Antioxidants/metabolism , Catalase , Dietary Supplements , Double-Blind Method , Glutathione Peroxidase/pharmacology , Humans , Muscle, Skeletal/physiology , Myalgia , Polyesters/pharmacology , Prunus avium/metabolism , Superoxide Dismutase-1/pharmacology
3.
Nutrients ; 13(12)2021 Nov 27.
Article in English | MEDLINE | ID: mdl-34959836

ABSTRACT

Shatavari has long been used as an Ayurvedic herb for women's health, but empirical evidence for its effectiveness has been lacking. Shatavari contains phytoestrogenic compounds that bind to the estradiol receptor. Postmenopausal estradiol deficiency contributes to sarcopenia and osteoporosis. In a randomised double-blind trial, 20 postmenopausal women (68.5 ± 6 years) ingested either placebo (N = 10) or shatavari (N = 10; 1000 mg/d, equivalent to 26,500 mg/d fresh weight shatavari) for 6 weeks. Handgrip and knee extensor strength were measured at baseline and at 6 weeks. Vastus lateralis (VL) biopsy samples were obtained. Data are presented as difference scores (Week 6-baseline, median ± interquartile range). Handgrip (but not knee extensor) strength was improved by shatavari supplementation (shatavari +0.7 ± 1.1 kg, placebo -0.4 ± 1.3 kg; p = 0.04). Myosin regulatory light chain phosphorylation, a known marker of improved myosin contractile function, was increased in VL following shatavari supplementation (immunoblotting; placebo -0.08 ± 0.5 a.u., shatavari +0.3 ± 1 arbitrary units (a.u.); p = 0.03). Shatavari increased the phosphorylation of Aktser473 (Aktser473 (placebo -0.6 ± 0.6 a.u., shatavari +0.2 ± 1.3 a.u.; p = 0.03) in VL. Shatavari supplementation did not alter plasma markers of bone turnover (P1NP, ß-CTX) and stimulation of human osteoblasts with pooled sera (N = 8 per condition) from placebo and shatavari supplementation conditions did not alter cytokine or metabolic markers of osteoblast activity. Shatavari may improve muscle function and contractility via myosin conformational change and further investigation of its utility in conserving and enhancing musculoskeletal function, in larger and more diverse cohorts, is warranted.


Subject(s)
Asparagus Plant , Dietary Supplements , Hand Strength , Phosphorylation/drug effects , Postmenopause/drug effects , Aged , Bone Remodeling/drug effects , Double-Blind Method , Female , Humans , Medicine, Ayurvedic , Middle Aged , Myosin Light Chains/drug effects , Postmenopause/physiology , Quadriceps Muscle/metabolism
4.
Sports (Basel) ; 9(4)2021 Mar 31.
Article in English | MEDLINE | ID: mdl-33807198

ABSTRACT

Tart cherry (TC) supplementation can improve exercise recovery and performance; and may also improve sleep duration and quality. This study investigated the use and knowledge of TC supplementation by athletes of all competitive levels. Eighty participants (52.5% elite (international, national, professional), 47.5% sub-elite (semi-professional, state/regional, county level, club level, recreational)) completed an online questionnaire investigating their attitudes towards and use of TC supplementation. Overall, 22.6% of participants were using or had previously used TC supplements, and 12.5% of participants planned to used TC supplements. Improved recovery (71.4%), sleep (32.1%) and immunity and general health (32.1%) were the most frequently indicated goals by respondents using TC supplements. In total, 32.1% of respondents were supplemented with TC chronically, 39.3% acutely and 28.6% used a combination of chronic and acute supplementation. The majority of those employing TC supplementation chronically used TC either over 2-3 days (37.0%) or continuously (37.0%). The most popular TC pre- and post-loading period was one day (34.3% and 41.5%, respectively). There were no significant differences between elite and sub-elite athletes in any parameters assessed (p > 0.05). TC supplementation is not widely used by the athletes surveyed, and athletes using TC supplements showed poor awareness of an evidence-led dosing strategy, regardless of competitive level.

5.
Front Nutr ; 8: 652094, 2021.
Article in English | MEDLINE | ID: mdl-33842524

ABSTRACT

Tart cherries (TC) are a rich source of polyphenols that elicit antioxidant and anti-inflammatory effects. As a consequence, the effects of TC derived supplements on markers of human health, exercise performance and sleep have been investigated. Supplementation protocols have been highly variable across studies and the dose of bioactive compounds used has often been poorly characterized. Specific and non-specific analytical methods were employed for measuring the total polyphenol and anthocyanin content in TC supplements. This review critically analyses the supplementation protocols and the analytical methods used for the characterization of TC supplements, culminating in recommendations for good practice in the analysis and reporting of the polyphenol content and profile of TC products. A literature search was conducted using PubMed/Medline and Web of Science up to May 4th, 2020, including studies published in all years prior. Only articles written in English that provided a TC dietary supplement as opposed to fresh whole TC were included in this review. Forty-three studies were identified as eligible and included for analysis in this review. The studies investigated the effects of TC supplementation on various aspects of human health, exercise recovery and performance and sleep. Twenty studies conducted an analysis of TC supplement and reported total polyphenol/anthocyanin content. Six studies did not report the polyphenol content of the TC supplement used. Seventeen studies reported the TC supplement polyphenol content but this was derived from previously published studies and presumably different supplement batches. The duration of the supplementation protocol ranged from acute supplementation to 84 days, meanwhile the total polyphenol and anthocyanin dose ranged from 143 to 2,140 mg/day and 15 to 547 mg/day, respectively. Due to the variety of specific and non-specific analytical methods used, the relative efficacy of different doses and polyphenol blends cannot reliably be extrapolated from critical analysis of the literature. Future studies should conduct an analysis of the study supplement batch. In addition to analysis and reporting of total polyphenol content, specific analytical methods such as HPLC UV/MS should be used to quantify total and individual anthocyanin contents.

6.
Sports (Basel) ; 9(1)2020 Dec 22.
Article in English | MEDLINE | ID: mdl-33374926

ABSTRACT

Tart cherry (TC) supplementation has been shown to accelerate post-exercise recovery, enhance endurance performance and improve sleep duration and quality. This study aimed to identify the use, practices and attitudes of sports nutrition and strength and conditioning practitioners towards tart cherry supplementation. Thirty-five practitioners anonymously completed an online survey investigating their use, practices and attitudes towards tart cherry supplements. Forty-six percent of the responders were currently recommending TC supplements, 11% had previously recommended TC supplements and 26% have not previously recommended TC supplements but were planning on doing so in the future. Of those recommending TC, 50% recommended or were planning on recommending TC supplements to enhance exercise recovery and 26% to improve sleep duration and quality. Acute supplementation and daily use during multi-day competition or demanding training blocks with a 2-3-day pre-load were the most reported supplementation recommendations (28% and 18%, respectively). Fifty-two percent of responders indicated uncertainty about the daily polyphenol dose to recommend as part of a TC supplementation protocol. Despite the high use and interest from sports nutrition and strength and conditioning practitioners in TC supplements, their practices did not align with the protocols found to be effective within the literature.

7.
Exp Physiol ; 105(12): 2178-2189, 2020 12.
Article in English | MEDLINE | ID: mdl-32965751

ABSTRACT

NEW FINDINGS: What is the central question of the study? Is Vps34 a nutrient-sensitive activator of mTORC1 in human skeletal muscle? What is the main finding and its importance? We show that altering nutrient availability, via protein-carbohydrate feeding, does not increase Vps34 kinase activity in human skeletal muscle. Instead, feeding increased Vps34-mTORC1 co-localization in parallel to increased mTORC1 activity. These findings may have important implications in the understanding nutrient-induced mTORC1 activation in skeletal muscle via interaction with Vps34. ABSTRACT: The Class III PI3Kinase, Vps34, has recently been proposed as a nutrient sensor, essential for activation of the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1). We therefore investigated the effects of increasing nutrient availability through protein-carbohydrate (PRO-CHO) feeding on Vps34 kinase activity and cellular localization in human skeletal muscle. Eight young, healthy males (21 ± 0.5 yrs, 77.7 ± 9.9 kg, 25.9 ± 2.7 kg/m2 , mean ± SD) ingested a PRO-CHO beverage containing 20/44/1 g PRO/CHO/FAT respectively, with skeletal muscle biopsies obtained at baseline and 1 h and 3 h post-feeding. PRO-CHO feeding did not alter Vps34 kinase activity, but did stimulate Vps34 translocation toward the cell periphery (PRE (mean ± SD) - 0.273 ± 0.040, 1 h - 0.348 ± 0.061, Pearson's Coefficient (r)) where it co-localized with mTOR (PRE - 0.312 ± 0.040, 1 h - 0.348 ± 0.069, Pearson's Coefficient (r)). These alterations occurred in parallel to an increase in S6K1 kinase activity (941 ± 466% of PRE at 1 h post-feeding). Subsequent in vitro experiments in C2C12 and human primary myotubes displayed no effect of the Vps34-specific inhibitor SAR405 on mTORC1 signalling responses to elevated nutrient availability. Therefore, in summary, PRO-CHO ingestion does not increase Vps34 activity in human skeletal muscle, whilst pharmacological inhibition of Vps34 does not prevent nutrient stimulation of mTORC1 in vitro. However, PRO-CHO ingestion promotes Vps34 translocation to the cell periphery, enabling Vps34 to associate with mTOR. Therefore, our data suggests that interaction between Vps34 and mTOR, rather than changes in Vps34 activity per se may be involved in PRO-CHO activation of mTORC1 in human skeletal muscle.


Subject(s)
Carbohydrates/administration & dosage , Class III Phosphatidylinositol 3-Kinases/metabolism , Eating/physiology , Muscle, Skeletal/metabolism , Adult , Animals , Cell Line , Humans , Male , Mice , Middle Aged , Muscle Fibers, Skeletal/metabolism , Signal Transduction/physiology , TOR Serine-Threonine Kinases/metabolism , Young Adult
8.
J Nutr Gerontol Geriatr ; 39(1): 1-15, 2020.
Article in English | MEDLINE | ID: mdl-31682788

ABSTRACT

We evaluated the effectiveness of a 3-week, daily meal provision service by a non-profit provider on the physical and psychological wellbeing of an older adult population. We further examined the feasibility of carrying out such measures in participant's homes. 19 older adult participants (8M, 11F; 78.3 ± 8.7 years) received 3 meals per day for 21 days and supplemented these meals ad libitum. Risk of malnutrition (Mini Nutritional Assessment; MNA) body composition, blood pressure, handgrip strength, balance, mobility, loneliness, social capital, satisfaction with life and mood were evaluated in participant's homes before and after the intervention. Following the intervention, MNA score increased significantly and participants rated themselves as significantly less depressed. We describe a methodology that was largely feasible and outline ways in which it could be improved. We have demonstrated that even short-term, home meal deliveries improve MNA scores and can positively alter some measures of mood.


Subject(s)
Food Services/standards , Home Care Services/standards , Meals , Mental Health/statistics & numerical data , Nutritional Status , Aged , Aged, 80 and over , Body Mass Index , Energy Intake , Feasibility Studies , Female , Hand Strength , Health Status , Humans , Male , Nutrition Assessment , Pilot Projects , Surveys and Questionnaires , United Kingdom
9.
Wellcome Open Res ; 4: 6, 2019.
Article in English | MEDLINE | ID: mdl-30906880

ABSTRACT

It is often desirable to characterise the morphology of myogenic cultures. To achieve this, the surface area of myotubes is often quantified, along with the nuclear fusion index (NFI). Existing methods of such quantification are time-consuming and subject to error-prone human input. We have developed MyoCount, an open-source program that runs via the freely available MATLAB Runtime and quantifies myotube surface area and NFI. MyoCount allows the user to adjust its parameters to account for differences in image quality, magnification and the colour channels used in generating the image. MyoCount measures of myotube surface area and NFI were compared to the mean of measures performed by two blinded investigators using ImageJ software (surface area R 2 = 0.89, NFI R 2 =0.87). For NFI, the mean coefficient of variation (CV) between two investigators (17.6 ± 2.3%) was significantly higher than that between the investigator mean and MyoCount (13.5 ± 1.4%). For measurements of myotube area, the CV did not differ between both analysis methods. Given these results and the advantages of applying the same image analysis method uniformly across all images in an experiment, we suggest that MyoCount will be a useful research tool and we publish its source code and instructions for its use alongside this article.

10.
Sci Rep ; 8(1): 15360, 2018 10 18.
Article in English | MEDLINE | ID: mdl-30337633

ABSTRACT

Adiposity and adipokines are implicated in the loss of skeletal muscle mass with age and in several chronic disease states. The aim of this study was to determine the effects of human obese and lean subcutaneous adipose tissue secretome on myogenesis and metabolism in skeletal muscle cells derived from both young (18-30 yr) and elderly (>65 yr) individuals. Obese subcutaneous adipose tissue secretome impaired the myogenesis of old myoblasts but not young myoblasts. Resistin was prolifically secreted by obese subcutaneous adipose tissue and impaired myotube thickness and nuclear fusion by activation of the classical NFκB pathway. Depletion of resistin from obese adipose tissue secretome restored myogenesis. Inhibition of the classical NFκB pathway protected myoblasts from the detrimental effect of resistin on myogenesis. Resistin also promoted intramyocellular lipid accumulation in myotubes and altered myotube metabolism by enhancing fatty acid oxidation and increasing myotube respiration and ATP production. In conclusion, resistin derived from human obese subcutaneous adipose tissue impairs myogenesis of human skeletal muscle, particularly older muscle, and alters muscle metabolism in developing myotubes. These findings may have important implications for the maintenance of muscle mass in older people with chronic inflammatory conditions, or older people who are obese or overweight.


Subject(s)
Muscle Fibers, Skeletal/pathology , Muscle, Skeletal/pathology , NF-kappa B/metabolism , Obesity/physiopathology , Resistin/metabolism , Subcutaneous Fat/physiopathology , Thinness , Adolescent , Adult , Aged , Cell Differentiation , Culture Media, Conditioned/pharmacology , Female , Humans , Male , Muscle Development/drug effects , Muscle Fibers, Skeletal/drug effects , Muscle Fibers, Skeletal/metabolism , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism , Young Adult
11.
Sci Rep ; 7(1): 12997, 2017 10 11.
Article in English | MEDLINE | ID: mdl-29021612

ABSTRACT

Studies in murine cell lines and in mouse models suggest that IL-15 promotes myogenesis and may protect against the inflammation-mediated skeletal muscle atrophy which occurs in sarcopenia and cachexia. The effects of IL-15 on human skeletal muscle growth and development remain largely uncharacterised. Myogenic cultures were isolated from the skeletal muscle of young and elderly subjects. Myoblasts were differentiated for 8 d, with or without the addition of recombinant cytokines (rIL-15, rTNFα) and an IL-15 receptor neutralising antibody. Although myotubes were 19% thinner in cultures derived from elderly subjects, rIL-15 increased the thickness of myotubes (MTT) from both age groups to a similar extent. Neutralisation of the high-affinity IL-15 receptor binding subunit, IL-15rα in elderly myotubes confirmed that autocrine concentrations of IL-15 also support myogenesis. Co-incubation of differentiating myoblasts with rIL-15 and rTNFα, limited the reduction in MTT and nuclear fusion index (NFI) associated with rTNFα stimulation alone. IL-15rα neutralisation and rTNFα decreased MTT and NFI further. This, coupled with our observation that myotubes secrete IL-15 in response to TNFα stimulation supports the notion that IL-15 serves to mitigate inflammatory skeletal muscle loss. IL-15 may be an effective therapeutic target for the attenuation of inflammation-mediated skeletal muscle atrophy.


Subject(s)
Interleukin-15/blood , Muscle Development/drug effects , Muscle Fibers, Skeletal/pathology , Tumor Necrosis Factor-alpha/adverse effects , Aged , Aging , Antibodies, Neutralizing/pharmacology , Cell Differentiation/drug effects , Cells, Cultured , Female , Gene Expression Regulation, Developmental/drug effects , Humans , Male , Muscle Fibers, Skeletal/drug effects , Muscle Fibers, Skeletal/metabolism , Recombinant Proteins/pharmacology
12.
Sci Rep ; 7(1): 5028, 2017 07 10.
Article in English | MEDLINE | ID: mdl-28694500

ABSTRACT

The mechanistic target of rapamycin (mTOR) is a central mediator of protein synthesis in skeletal muscle. We utilized immunofluorescence approaches to study mTOR cellular distribution and protein-protein co-localisation in human skeletal muscle in the basal state as well as immediately, 1 and 3 h after an acute bout of resistance exercise in a fed (FED; 20 g Protein/40 g carbohydrate/1 g fat) or energy-free control (CON) state. mTOR and the lysosomal protein LAMP2 were highly co-localised in basal samples. Resistance exercise resulted in rapid translocation of mTOR/LAMP2 towards the cell membrane. Concurrently, resistance exercise led to the dissociation of TSC2 from Rheb and increased in the co-localisation of mTOR and Rheb post exercise in both FED and CON. In addition, mTOR co-localised with Eukaryotic translation initiation factor 3 subunit F (eIF3F) at the cell membrane post-exercise in both groups, with the response significantly greater at 1 h of recovery in the FED compared to CON. Collectively our data demonstrate that cellular trafficking of mTOR occurs in human muscle in response to an anabolic stimulus, events that appear to be primarily influenced by muscle contraction. The translocation and association of mTOR with positive regulators (i.e. Rheb and eIF3F) is consistent with an enhanced mRNA translational capacity after resistance exercise.


Subject(s)
Eukaryotic Initiation Factor-3/metabolism , Lysosomal-Associated Membrane Protein 2/metabolism , Muscle, Skeletal/metabolism , Ras Homolog Enriched in Brain Protein/metabolism , Resistance Training/methods , TOR Serine-Threonine Kinases/metabolism , Tuberous Sclerosis Complex 2 Protein/metabolism , Adult , Cell Membrane/metabolism , Dietary Carbohydrates/administration & dosage , Dietary Proteins/administration & dosage , Female , Humans , Male , Muscle Contraction , Protein Binding , Protein Transport , Young Adult
SELECTION OF CITATIONS
SEARCH DETAIL
...