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Papers by Roger Hurst

Research paper thumbnail of A Simple, Robust, and Convenient HPLC Assay for Urinary Lactulose and Mannitol in the Dual Sugar Absorption Test

Molecules, Apr 21, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Daily Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants for 5 Weeks Supports Exercise Recovery Through the Management of Oxidative Stress and Inflammation: A Randomized Placebo Controlled Pilot Study

Frontiers in Nutrition, Feb 27, 2020

Conclusions: Daily consumption of BAE for 5 weeks serves to enhance the exercise recovery effecti... more Conclusions: Daily consumption of BAE for 5 weeks serves to enhance the exercise recovery effectiveness of a single consumption of BAE and promotes beneficial/ protective antioxidant/anti-inflammatory cellular events that facilitate exercise recovery.

Research paper thumbnail of Blackcurrant proanthocyanidins augment IFN-γ-induced suppression of IL-4 stimulated CCL26 secretion in alveolar epithelial cells

Molecular Nutrition & Food Research, Mar 12, 2010

Epidemiological studies reveal that fruit consumption reduces the prevalence of airway inflammati... more Epidemiological studies reveal that fruit consumption reduces the prevalence of airway inflammation and childhood asthma. In particular, blackcurrant polyphenolic extracts have been shown to alleviate lung inflammation. Since IL-4-stimulated eotaxin-3 (CCL26) secretion is a major factor in the continuous eosinophil recruitment observed in atopic asthma, our focus was to evaluate the effectiveness of blackcurrant polyphenolic compounds on CCL26 secretion in human alveolar epithelial cells. Our results indicate that a proanthocyanin-enriched blackcurrant extract (BC-P), but not anthocyanin-enriched blackcurrant extract suppressed both IL-4-and IL-13-stimulated CCL26 secretion in a dose-dependent manner. Furthermore pre-incubation of cells with BC-P caused a time-dependent suppression of IL-4-stimulated CCL26 secretion. Moreover, epigallocatechin (EGC), and to a lesser extent epicatechin, metabolites identified in the proanthocyanidin extract, suppressed IL-4-stimulated CCL26 secretion. EGC was also effective at reducing the cellular phosphorylated STAT-6/STAT-6 ratio. Furthermore, both BC-P and purified EGC potentiated the ability of IFN-g to suppress IL-4-stimulated CCL26 secretion. The progression of an allergic immune response is complex, identifying plant compounds that target specific cellular events and complement the body's own immune actions is important for the development of functional foods. Our findings support the potential for blackcurrant polyphenolic compounds to reduce eosinophil recruitment and alleviate eosinophilic-driven airway inflammation.

Research paper thumbnail of The protection of bovine skeletal myofibrils from proteolytic damage post mortem by small heat shock proteins

Meat Science, Aug 1, 2014

This study aimed to determine how small heat shock proteins (sHSPs) protect myofibrillar proteins... more This study aimed to determine how small heat shock proteins (sHSPs) protect myofibrillar proteins from μ-calpain degradation during ageing. Immunoprecipitation experiments with M. longissimus dorsi (LD) from Angus heifers (n = 14) examined the interaction between αβ-crystallin, desmin, titin, HSP20, HSP27 and μ-calpain. Results showed that αβ-crystallin associated with desmin, titin, HSP20, HSP27 and μ-calpain. Exogenous αβ-crystallin reduced desmin and titin degradations in myofibrillar extracts and attenuated μ-calpain activity. In a second experiment, bull LD (n = 94) were aged at −1.5°C for up to 28 days post mortem. μ-Calpain autolysed faster in high ultimate pH (pH u) meat (pH u ≥ 6.2) and this was concomitant with the more rapid degradation of titin and filamin in this pH u group. Desmin stability in intermediate pH u meat (pH u 5.8 to 6.19) may be due to the protection of myofibril-bound sHSPs combined with the competitive inhibition of μ-calpain by sHSPs.

Research paper thumbnail of Timed consumption of a New Zealand blackcurrant juice support positive affective responses during a self-motivated moderate walking exercise in healthy sedentary adults

Journal of the International Society of Sports Nutrition, Jan 15, 2019

Background: Affective responses experienced during exercise are a significant determinant on exer... more Background: Affective responses experienced during exercise are a significant determinant on exercise adherence. We have previously demonstrated that consumption of New Zealand (NZ) blackcurrants preserves cognition by attenuating the feeling of fatigue. This positive affective response correlated with the ability of blackcurrant polyphenols to support monoamine neurotransmission via inhibition of monoamine oxidase-B (MAO-B) activity. Here we explore how the consumption of a NZ blackcurrant juice (BJ) influenced affective responses and potential ergogenic action on the motivation to adhere to a low impact walking exercise. Methods: In a parallel randomized controlled study (Trial registration #: ACTRN12617000319370p, registered 28th February 2017, http://www.anzctr.org.au/), 40 healthy sedentary male and female participants drank a BJ or matched placebo (PLA) (n = 20 per group), 1 h prior to a self-motivated treadmill walk, where heart rate and affective responses (exertion [ES] or feeling / mood [FS]) scores) were recorded at 3 or 5 min intervals. Blood glucose, lactate, malondialdehyde (MDA) and platelet MAO-B activity were measured pre-and post-exercise and comparisons were conducted using with Student's t-tests. Subjective data were analysed using 2-way ANOVA with appropriate post hoc tests. Results: Consuming a BJ 1 h prior to exercise caused a 90% decline in platelet MAO-B activity. The exercise had no significant (p > 0.05) effect on blood lactate, glucose or plasma MDA levels. Assessment of affective responses over the first 60 mins (adjusting for participant drop-out) revealed a time-dependent ES increase in both groups, with ES reported by participants in the BJ group consistently lower than those in the PLA group (p < 0.05). FS declined in PLA and BJ groups over 60 mins, but an inverse relationship with ES was only observed within the PLA group (r 2 = 0.99, p = 0.001). Whilst the average time walked by participants in the BJ group was 11 mins longer than the PLA group (p = 0.3), and 30% of the BJ group achieving > 10 km compared to only 10% for the PLA group (p = 0.28), statistical significance was not achieved.

Research paper thumbnail of Short-term blackcurrant extract consumption modulates exercise-induced oxidative stress and lipopolysaccharide-stimulated inflammatory responses

American Journal of Physiology-regulatory Integrative and Comparative Physiology, Jul 1, 2009

Research paper thumbnail of Effect of New Zealand blueberry consumption on recovery from eccentric exercise-induced muscle damage

Journal of the International Society of Sports Nutrition, Feb 6, 2012

Background: Exercise-induced muscle damage (EIMD) is accompanied by localized oxidative stress / ... more Background: Exercise-induced muscle damage (EIMD) is accompanied by localized oxidative stress / inflammation which, in the short-term at least, is associated with impaired muscular performance. Dietary antioxidants have been shown to reduce excessive oxidative stress; however, their effectiveness in facilitating recovery following EIMD is not clear. Blueberries demonstrate antioxidant and anti-inflammatory properties. In this study we examine the effect of New Zealand blueberries on EIMD after strenuous eccentric exercise. Methods: In a randomized cross-over design, 10 females consumed a blueberry smoothie or placebo of a similar antioxidant capacity 5 and 10 hours prior to and then immediately, 12 and 36 hours after EIMD induced by 300 strenuous eccentric contractions of the quadriceps. Absolute peak and average peak torque across the knee, during concentric, isometric, and eccentric actions were measured. Blood biomarkers of oxidative stress, antioxidant capacity, and inflammation were assessed at 12, 36 and 60 hours post exercise. Data were analyzed using a two-way ANOVA. Results: A significant (p < 0.001) decrease in isometric, concentric and eccentric torque was observed 12 hours following exercise in both treatment groups. During the 60 hour recovery period, a significant (p = 0.047) interaction effect was seen for peak isometric tension suggesting a faster rate of recovery in the blueberry intervention group. A similar trend was observed for concentric and eccentric strength. An increase in oxidative stress and inflammatory biomarkers was also observed in both treatment groups following EIMD. Although a faster rate of decrease in oxidative stress was observed in the blueberry group, it was not significant (p < 0.05) until 36 hours post-exercise and interestingly coincided with a gradual increase in plasma antioxidant capacity, whereas biomarkers for inflammation were still elevated after 60 hours recovery. Conclusions: This study demonstrates that the ingestion of a blueberry smoothie prior to and after EIMD accelerates recovery of muscle peak isometric strength. This effect, although independent of the beverage's inherent antioxidant capacity, appears to involve an up-regulation of adaptive processes, i.e. endogenous antioxidant processes, activated by the combined actions of the eccentric exercise and blueberry consumption. These findings may benefit the sporting community who should consider dietary interventions that specifically target health and performance adaptation.

Research paper thumbnail of Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants Prior to Exercise May Assist Recovery From Oxidative Stress and Maintains Circulating Neutrophil Function: A Pilot Study

Frontiers in Nutrition, May 29, 2019

To evaluate blackcurrant anthocyanin-rich extract (BAE) consumption on time-and dose-dependent pl... more To evaluate blackcurrant anthocyanin-rich extract (BAE) consumption on time-and dose-dependent plasma anthocyanin bioavailability and conduct a pilot study to explore the potential effect of BAE in promoting recovery from exercise-induced oxidative stress, and maintenance of circulating neutrophil function. Conclusions: Consumption of BAE (>1.6 mg/kg) 1 h prior to exercise facilitated recovery from exercise-induced oxidative stress and preserved circulating neutrophil function. This study provides data to underpin a larger study designed to evaluate the efficacy of timed BAE consumption on post-exercise recovery and innate immunity.

Research paper thumbnail of Post-Exercise Skeletal Muscle Glycogen Related to Plasma Cytokines and Muscle IL-6 Protein Content, but not Muscle Cytokine mRNA Expression

Frontiers in Nutrition, Sep 9, 2015

Post-exercise skeletal muscle glycogen related to plasma cytokines and muscle IL-6 protein conten... more Post-exercise skeletal muscle glycogen related to plasma cytokines and muscle IL-6 protein content, but not muscle cytokine mRNA expression.

Research paper thumbnail of Exercise-induced elevation in plasma oxidative generating capability augments the temporal inflammatory response stimulated by lipopolysaccharide

European Journal of Applied Physiology, Jun 7, 2009

Prolonged oxidative stress is detrimental to health; however, transient oxidative stress may impr... more Prolonged oxidative stress is detrimental to health; however, transient oxidative stress may improve immune capability. We examined whether exercise-induced increases in the plasma oxidative generating capability enhance immune responsiveness to potential pathogens. Twelve individuals underwent a 30-min row and pre and post-exercise bloods were collected for oxidative stress and immune assessment. We found that exercise induced a transient increase in plasma carbonyls (3.2-5.3 nmol/mg protein) and creatine kinase activity (0.5-1.2 absorbance/min/mg protein) and that lipopolysaccharide (LPS) stimulation (0.5-24 h) of pre- and post-exercise blood augmented temporal tumour necrosis factor-alpha (TNFalpha) secretion. Further characterisation of plasma using a modified dihydro-2&amp;amp;amp;amp;amp;amp;#39;,7&amp;amp;amp;amp;amp;amp;#39;-dichlorohydrofluorescein (DCF) assay revealed that addition of a sub-threshold of hydrogen peroxide to post-exercise (and not pre-exercise) plasma caused a sixfold increase in the radical oxygen species (ROS) generating capability after 15 min (555 +/- 131 to 3607 +/- 488 change in fluorescent intensity [DeltaFI]), which was inhibited using 60 mM N-acetyl-L: -cysteine (920 +/- 154 DeltaFI). Furthermore, cell experiments revealed that LPS stimulation of either THP-1 cells pre-incubated with post-exercise plasma or peripheral blood mononuclear cells pre-treated with pro-oxidants, modulated the temporal secretion of key cytokines that regulate the initiation, progression and resolution of an inflammatory response. These results indicate that exercise-induced changes in plasma parameters (e.g. oxidative generating capability-dependent or independent of inflammatory mediators) augment the temporal LPS response and support the notion that repeated transient oxidative stress (such as that induced by regular exercise) is important for a &amp;amp;amp;amp;amp;amp;quot;healthy&amp;amp;amp;amp;amp;amp;quot; immune system.

Research paper thumbnail of Post-Exercise Skeletal Muscle Glycogen Related to Plasma Cytokine but Not Muscle mRNA Expression

Medicine and Science in Sports and Exercise, May 1, 2015

performed the exercise bout (60%VO 2peak ; ~30-135 minutes) on a treadmill 45 minutes post-HFM (6... more performed the exercise bout (60%VO 2peak ; ~30-135 minutes) on a treadmill 45 minutes post-HFM (63% fat, 10kcal/kg of body weight). Blood lipids and exhaled nitric oxide (eNO) were measured at baseline and 2 h and 4 h post-HFM. Sputum differential cell counts were performed at baseline and 4 h post-HFM to assess airway inflammation. RESULTS: Triglycerides increased significantly in ACT CON and ACT EX 2 h (~54%, p=0.001; ~66%, p=0.013, respectively) and 4 h (~107%, p=0.001; ~119%, p=0.004, respectively) post-HFM and also IN CON at 4 h (~44%; p= 0.004) and IN EX (2 h, ~62%, p= 0.001; 4 h, ~93%, p=0.001) post-HFM. Area under the curve (AUC) was significantly lower in ACT EX (p<0.001) than ACT CON and IN EX, but was not significantly different in IN CON versus IN EX (p>0.05). Exhaled nitric oxide increased non-linearly from baseline to 2 and 4 h post-HFM in ACT (p<0.05, η 2 =0.36) and IN (<0.05), but was not dependent on condition. CONCLUSION: Preliminary findings suggest that in both active and inactive subjects, an exercise bout after a HFM did not reduce post-prandial airway inflammation. However, the exercise bout was effective in reducing PPL in active subjects, but not inactive subjects. Post-prandial airway inflammation occurred following a high-fat meal regardless of a reduction in post-prandial triglycerides.

Research paper thumbnail of The in vitro evaluation of isolated procyanidins as modulators of cytokine-induced eotaxin production in human alveolar epithelial cells

Journal of Berry Research, Jun 16, 2016

BACKGROUND: Populations that consume procyanidin-rich diets are less susceptible to inflammatory ... more BACKGROUND: Populations that consume procyanidin-rich diets are less susceptible to inflammatory disease. Allergic asthma is an inflammatory lung disease perpetuated by a hyperreactive airway epithelium and eosinophil infiltration into the lung. Eotaxin-1 (CCL11) mediates eosinophil migration into tissues and its modulation could represent a means to assist the management of airway inflammation. OBJECTIVE: Here we evaluated procyanidins as a means of modulating CCL11 production in vitro. METHODS: We used human lung epithelial cells (A549) and optimized the conditions to induce CCL11 production in vitro. Cells were exposed to procyanidins for 6 h prior to an inflammatory insult of 5 ng/mL IL-4 with 5 ng/mL TNF␣ for 48 h. An enzyme-linked immunosorbent assay was used to measure CCL11 production. RESULTS: Cells exposed to 5 M procyanidin A2 prior to the inflammatory challenge showed significantly inhibited (36%) CCL11 production. Under the same conditions, procyanidins B1 and B2 elicited no effect. Furthermore, combinations of procyanidins A2 and B2 (5 M total) demonstrated no evidence of a synergistic interaction. CONCLUSIONS: These data demonstrate that the regulation of CCL11 by lung epithelial cells is not ubiquitous among the three investigated procyanidins. We demonstrate a differential inhibition of CCL11 by A-type and B-type procyanidins. This evidence supports further studies into procyanidins, specifically A-type, for managing inappropriate airway inflammation.

Research paper thumbnail of Boysenberry and apple juice concentrate reduced acute lung inflammation and increased M2 macrophage‐associated cytokines in an acute mouse model of allergic airways disease

Food Science & Nutrition, 2021

Bioactive compounds including anthocyanins and other polyphenols are associated with reduced lung... more Bioactive compounds including anthocyanins and other polyphenols are associated with reduced lung inflammation and improved lung function in asthma and other lung diseases. This study investigated the effects of a Boysenberry and apple juice concentrate, high in cyanidin glycosides, ellagitannins, and chlorogenic acid, on a mouse model of allergic airways inflammation. Male C57BL/6J mice were orally gavaged with 2.5 mg/kg of total anthocyanins (TAC) from BerriQi® Boysenberry and apple juice concentrate (0.2 mg/kg human equivalent dose) or water control 1 hr before an acute intranasal ovalbumin (OVA) challenge and were gavaged again 2 days after the intranasal challenge. Consumption of BerriQi® Boysenberry and apple juice concentrate significantly decreased OVA‐induced infiltrating eosinophils, neutrophils, and T cells in the lung, and mucous production. Quantification of gene expression for arginase (Arg1), chitinase 3‐like 3 (Ym‐1), found in inflammatory zone (Fizz1), which have be...

Research paper thumbnail of Anthocyanin-Rich New Zealand Blackcurrant Extract Supports the Maintenance of Forearm Blood-Flow During Prolonged Sedentary Sitting

Frontiers in Nutrition, 2020

Objectives: We examined the acute effects of anthocyanin-rich New Zealand blackcurrant extract an... more Objectives: We examined the acute effects of anthocyanin-rich New Zealand blackcurrant extract and a placebo on hemodynamics during 120 min of sedentary sitting in healthy males. Additionally, we investigated whether changes in resting hemodynamics altered repeated isometric hand-grip exercise performance and post exercise forearm blood flow (FBF). Methods: Ten healthy males completed two trials during which they ingested either blackcurrant extract (1.87 mg total anthocyanins/kg bodyweight) or placebo powder. Heart rate, blood pressure and forearm blood flow were measured, and venous blood was sampled, prior to and 30, 60, 90 and 120 min-post ingestion. Participants remained seated for the duration of each trial. At 120 min post-ingestion participants completed as many repetitions of isometric hand-grip contractions as possible. Results: Heart rate, blood pressure and mean arterial pressure changed over time (all p < 0.001) but did not differ between treatments. A treatment x time interaction for FBF (p = 0.025) and forearm vascular resistance (FVR) (p = 0.002) was found. No difference in the number of isometric hand-grip contractions was observed between treatments (p = 0.68) nor was there any treatment x time interaction in post-exercise FBF (p = 0.997). Plasma endothelin-1 (p = 0.023) and nitrate (p = 0.047) changed over time but did not differ between treatments (both p > 0.1). Plasma nitrite did not change over time (p = 0.732) or differ between treatments (p = 0.373). Conclusion: This study demonstrated that acute ingestion of a single dose of blackcurrant extract maintained FBF and FVR during an extended period of sitting; however, this did not influence exercise performance during hand-grip exercise.

Research paper thumbnail of Fruits and Vegetables as Functional Foods for Exercise and Inflammation

Elsevier eBooks, 2013

Fruits and vegetables are good sources of polyphenolic compounds with antioxidant abilities, lead... more Fruits and vegetables are good sources of polyphenolic compounds with antioxidant abilities, leading to the theory that a control of oxidative stress is responsible for the health benefits of a diet rich in these foods. However, there is a lack of strong supportive data from human studies and evidence indicates that polyphenolic compounds also have anti-inflammatory and immune-modulatory activity. This chapter summarizes the evidence for the effects of polyphenolic compounds on modulating oxidative stress and inflammation with regard to exercise performance and asthma with a perspective on the usefulness of fruit and vegetables and/or derived bioactives as functional foods.

Research paper thumbnail of Muscle Glycogen Depletion Following 75-km of Cycling Is Not Linked to Increased Muscle IL-6, IL-8, and MCP-1 mRNA Expression and Protein Content

Frontiers in Physiology, 2016

The cytokine response to heavy exertion varies widely for unknown reasons, and this study evaluat... more The cytokine response to heavy exertion varies widely for unknown reasons, and this study evaluated the relative importance of glycogen depletion, muscle damage, and stress hormone changes on blood and muscle cytokine measures. Cyclists (N = 20) participated in a 75-km cycling time trial (168 ± 26.0 min), with blood and vastus lateralis muscle samples collected before and after. Muscle glycogen decreased 77.2 ± 17.4%,

Research paper thumbnail of Correction to: The effect of New Zealand blackcurrant on sport performance and related biomarkers: a systematic review and meta-analysis

Journal of the International Society of Sports Nutrition, 2021

An amendment to this paper has been published and can be accessed via the original article.

Research paper thumbnail of Effects of α-adrenergic antagonists on insulin secretion from rat pancreatic islets

Biochemical Society Transactions, 1988

Research paper thumbnail of Daily Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants for 5 Weeks Supports Exercise Recovery Through the Management of Oxidative Stress and Inflammation: A Randomized Placebo Controlled Pilot Study

Frontiers in Nutrition, 2020

Conclusions: Daily consumption of BAE for 5 weeks serves to enhance the exercise recovery effecti... more Conclusions: Daily consumption of BAE for 5 weeks serves to enhance the exercise recovery effectiveness of a single consumption of BAE and promotes beneficial/ protective antioxidant/anti-inflammatory cellular events that facilitate exercise recovery.

Research paper thumbnail of A Simple, Robust, and Convenient HPLC Assay for Urinary Lactulose and Mannitol in the Dual Sugar Absorption Test

Molecules

Background: Heterogeneous laborious analytical methodologies for the determination of urinary lac... more Background: Heterogeneous laborious analytical methodologies for the determination of urinary lactulose and mannitol limit their utility in intestinal permeability testing. Methods: We developed an assay using a Shimadzu HPLC system, an Aminex HPX87C column, and refractive index detection. The test was calibrated using a series of dilutions from standard stock solutions of lactulose and mannitol ‘spiked’ into urine samples. The utility to quantify urinary excretion during the dual sugar absorption test over 6 h was also determined. Results: Lactulose and mannitol were eluted isocratically at 5.7 and 10.1 min, respectively, with water as a mobile phase at a flow rate of 0.3 mL min−1, 858 psi, 60 °C. The calibration curves for both sugars were linear up to 500 µg mL−1 with a limit of detection in standard solutions at 4 µg mL−1 and in ‘spiked’ urine samples at 15 µg mL−1. The intra-assay and inter-assay CVs were between 2.0–5.1% and 2.0–5.1% for lactulose and 2.5–4.4% and 2.8–3.9% for...

Research paper thumbnail of A Simple, Robust, and Convenient HPLC Assay for Urinary Lactulose and Mannitol in the Dual Sugar Absorption Test

Molecules, Apr 21, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Research paper thumbnail of Daily Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants for 5 Weeks Supports Exercise Recovery Through the Management of Oxidative Stress and Inflammation: A Randomized Placebo Controlled Pilot Study

Frontiers in Nutrition, Feb 27, 2020

Conclusions: Daily consumption of BAE for 5 weeks serves to enhance the exercise recovery effecti... more Conclusions: Daily consumption of BAE for 5 weeks serves to enhance the exercise recovery effectiveness of a single consumption of BAE and promotes beneficial/ protective antioxidant/anti-inflammatory cellular events that facilitate exercise recovery.

Research paper thumbnail of Blackcurrant proanthocyanidins augment IFN-γ-induced suppression of IL-4 stimulated CCL26 secretion in alveolar epithelial cells

Molecular Nutrition & Food Research, Mar 12, 2010

Epidemiological studies reveal that fruit consumption reduces the prevalence of airway inflammati... more Epidemiological studies reveal that fruit consumption reduces the prevalence of airway inflammation and childhood asthma. In particular, blackcurrant polyphenolic extracts have been shown to alleviate lung inflammation. Since IL-4-stimulated eotaxin-3 (CCL26) secretion is a major factor in the continuous eosinophil recruitment observed in atopic asthma, our focus was to evaluate the effectiveness of blackcurrant polyphenolic compounds on CCL26 secretion in human alveolar epithelial cells. Our results indicate that a proanthocyanin-enriched blackcurrant extract (BC-P), but not anthocyanin-enriched blackcurrant extract suppressed both IL-4-and IL-13-stimulated CCL26 secretion in a dose-dependent manner. Furthermore pre-incubation of cells with BC-P caused a time-dependent suppression of IL-4-stimulated CCL26 secretion. Moreover, epigallocatechin (EGC), and to a lesser extent epicatechin, metabolites identified in the proanthocyanidin extract, suppressed IL-4-stimulated CCL26 secretion. EGC was also effective at reducing the cellular phosphorylated STAT-6/STAT-6 ratio. Furthermore, both BC-P and purified EGC potentiated the ability of IFN-g to suppress IL-4-stimulated CCL26 secretion. The progression of an allergic immune response is complex, identifying plant compounds that target specific cellular events and complement the body's own immune actions is important for the development of functional foods. Our findings support the potential for blackcurrant polyphenolic compounds to reduce eosinophil recruitment and alleviate eosinophilic-driven airway inflammation.

Research paper thumbnail of The protection of bovine skeletal myofibrils from proteolytic damage post mortem by small heat shock proteins

Meat Science, Aug 1, 2014

This study aimed to determine how small heat shock proteins (sHSPs) protect myofibrillar proteins... more This study aimed to determine how small heat shock proteins (sHSPs) protect myofibrillar proteins from μ-calpain degradation during ageing. Immunoprecipitation experiments with M. longissimus dorsi (LD) from Angus heifers (n = 14) examined the interaction between αβ-crystallin, desmin, titin, HSP20, HSP27 and μ-calpain. Results showed that αβ-crystallin associated with desmin, titin, HSP20, HSP27 and μ-calpain. Exogenous αβ-crystallin reduced desmin and titin degradations in myofibrillar extracts and attenuated μ-calpain activity. In a second experiment, bull LD (n = 94) were aged at −1.5°C for up to 28 days post mortem. μ-Calpain autolysed faster in high ultimate pH (pH u) meat (pH u ≥ 6.2) and this was concomitant with the more rapid degradation of titin and filamin in this pH u group. Desmin stability in intermediate pH u meat (pH u 5.8 to 6.19) may be due to the protection of myofibril-bound sHSPs combined with the competitive inhibition of μ-calpain by sHSPs.

Research paper thumbnail of Timed consumption of a New Zealand blackcurrant juice support positive affective responses during a self-motivated moderate walking exercise in healthy sedentary adults

Journal of the International Society of Sports Nutrition, Jan 15, 2019

Background: Affective responses experienced during exercise are a significant determinant on exer... more Background: Affective responses experienced during exercise are a significant determinant on exercise adherence. We have previously demonstrated that consumption of New Zealand (NZ) blackcurrants preserves cognition by attenuating the feeling of fatigue. This positive affective response correlated with the ability of blackcurrant polyphenols to support monoamine neurotransmission via inhibition of monoamine oxidase-B (MAO-B) activity. Here we explore how the consumption of a NZ blackcurrant juice (BJ) influenced affective responses and potential ergogenic action on the motivation to adhere to a low impact walking exercise. Methods: In a parallel randomized controlled study (Trial registration #: ACTRN12617000319370p, registered 28th February 2017, http://www.anzctr.org.au/), 40 healthy sedentary male and female participants drank a BJ or matched placebo (PLA) (n = 20 per group), 1 h prior to a self-motivated treadmill walk, where heart rate and affective responses (exertion [ES] or feeling / mood [FS]) scores) were recorded at 3 or 5 min intervals. Blood glucose, lactate, malondialdehyde (MDA) and platelet MAO-B activity were measured pre-and post-exercise and comparisons were conducted using with Student's t-tests. Subjective data were analysed using 2-way ANOVA with appropriate post hoc tests. Results: Consuming a BJ 1 h prior to exercise caused a 90% decline in platelet MAO-B activity. The exercise had no significant (p > 0.05) effect on blood lactate, glucose or plasma MDA levels. Assessment of affective responses over the first 60 mins (adjusting for participant drop-out) revealed a time-dependent ES increase in both groups, with ES reported by participants in the BJ group consistently lower than those in the PLA group (p < 0.05). FS declined in PLA and BJ groups over 60 mins, but an inverse relationship with ES was only observed within the PLA group (r 2 = 0.99, p = 0.001). Whilst the average time walked by participants in the BJ group was 11 mins longer than the PLA group (p = 0.3), and 30% of the BJ group achieving > 10 km compared to only 10% for the PLA group (p = 0.28), statistical significance was not achieved.

Research paper thumbnail of Short-term blackcurrant extract consumption modulates exercise-induced oxidative stress and lipopolysaccharide-stimulated inflammatory responses

American Journal of Physiology-regulatory Integrative and Comparative Physiology, Jul 1, 2009

Research paper thumbnail of Effect of New Zealand blueberry consumption on recovery from eccentric exercise-induced muscle damage

Journal of the International Society of Sports Nutrition, Feb 6, 2012

Background: Exercise-induced muscle damage (EIMD) is accompanied by localized oxidative stress / ... more Background: Exercise-induced muscle damage (EIMD) is accompanied by localized oxidative stress / inflammation which, in the short-term at least, is associated with impaired muscular performance. Dietary antioxidants have been shown to reduce excessive oxidative stress; however, their effectiveness in facilitating recovery following EIMD is not clear. Blueberries demonstrate antioxidant and anti-inflammatory properties. In this study we examine the effect of New Zealand blueberries on EIMD after strenuous eccentric exercise. Methods: In a randomized cross-over design, 10 females consumed a blueberry smoothie or placebo of a similar antioxidant capacity 5 and 10 hours prior to and then immediately, 12 and 36 hours after EIMD induced by 300 strenuous eccentric contractions of the quadriceps. Absolute peak and average peak torque across the knee, during concentric, isometric, and eccentric actions were measured. Blood biomarkers of oxidative stress, antioxidant capacity, and inflammation were assessed at 12, 36 and 60 hours post exercise. Data were analyzed using a two-way ANOVA. Results: A significant (p < 0.001) decrease in isometric, concentric and eccentric torque was observed 12 hours following exercise in both treatment groups. During the 60 hour recovery period, a significant (p = 0.047) interaction effect was seen for peak isometric tension suggesting a faster rate of recovery in the blueberry intervention group. A similar trend was observed for concentric and eccentric strength. An increase in oxidative stress and inflammatory biomarkers was also observed in both treatment groups following EIMD. Although a faster rate of decrease in oxidative stress was observed in the blueberry group, it was not significant (p < 0.05) until 36 hours post-exercise and interestingly coincided with a gradual increase in plasma antioxidant capacity, whereas biomarkers for inflammation were still elevated after 60 hours recovery. Conclusions: This study demonstrates that the ingestion of a blueberry smoothie prior to and after EIMD accelerates recovery of muscle peak isometric strength. This effect, although independent of the beverage's inherent antioxidant capacity, appears to involve an up-regulation of adaptive processes, i.e. endogenous antioxidant processes, activated by the combined actions of the eccentric exercise and blueberry consumption. These findings may benefit the sporting community who should consider dietary interventions that specifically target health and performance adaptation.

Research paper thumbnail of Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants Prior to Exercise May Assist Recovery From Oxidative Stress and Maintains Circulating Neutrophil Function: A Pilot Study

Frontiers in Nutrition, May 29, 2019

To evaluate blackcurrant anthocyanin-rich extract (BAE) consumption on time-and dose-dependent pl... more To evaluate blackcurrant anthocyanin-rich extract (BAE) consumption on time-and dose-dependent plasma anthocyanin bioavailability and conduct a pilot study to explore the potential effect of BAE in promoting recovery from exercise-induced oxidative stress, and maintenance of circulating neutrophil function. Conclusions: Consumption of BAE (>1.6 mg/kg) 1 h prior to exercise facilitated recovery from exercise-induced oxidative stress and preserved circulating neutrophil function. This study provides data to underpin a larger study designed to evaluate the efficacy of timed BAE consumption on post-exercise recovery and innate immunity.

Research paper thumbnail of Post-Exercise Skeletal Muscle Glycogen Related to Plasma Cytokines and Muscle IL-6 Protein Content, but not Muscle Cytokine mRNA Expression

Frontiers in Nutrition, Sep 9, 2015

Post-exercise skeletal muscle glycogen related to plasma cytokines and muscle IL-6 protein conten... more Post-exercise skeletal muscle glycogen related to plasma cytokines and muscle IL-6 protein content, but not muscle cytokine mRNA expression.

Research paper thumbnail of Exercise-induced elevation in plasma oxidative generating capability augments the temporal inflammatory response stimulated by lipopolysaccharide

European Journal of Applied Physiology, Jun 7, 2009

Prolonged oxidative stress is detrimental to health; however, transient oxidative stress may impr... more Prolonged oxidative stress is detrimental to health; however, transient oxidative stress may improve immune capability. We examined whether exercise-induced increases in the plasma oxidative generating capability enhance immune responsiveness to potential pathogens. Twelve individuals underwent a 30-min row and pre and post-exercise bloods were collected for oxidative stress and immune assessment. We found that exercise induced a transient increase in plasma carbonyls (3.2-5.3 nmol/mg protein) and creatine kinase activity (0.5-1.2 absorbance/min/mg protein) and that lipopolysaccharide (LPS) stimulation (0.5-24 h) of pre- and post-exercise blood augmented temporal tumour necrosis factor-alpha (TNFalpha) secretion. Further characterisation of plasma using a modified dihydro-2&amp;amp;amp;amp;amp;amp;#39;,7&amp;amp;amp;amp;amp;amp;#39;-dichlorohydrofluorescein (DCF) assay revealed that addition of a sub-threshold of hydrogen peroxide to post-exercise (and not pre-exercise) plasma caused a sixfold increase in the radical oxygen species (ROS) generating capability after 15 min (555 +/- 131 to 3607 +/- 488 change in fluorescent intensity [DeltaFI]), which was inhibited using 60 mM N-acetyl-L: -cysteine (920 +/- 154 DeltaFI). Furthermore, cell experiments revealed that LPS stimulation of either THP-1 cells pre-incubated with post-exercise plasma or peripheral blood mononuclear cells pre-treated with pro-oxidants, modulated the temporal secretion of key cytokines that regulate the initiation, progression and resolution of an inflammatory response. These results indicate that exercise-induced changes in plasma parameters (e.g. oxidative generating capability-dependent or independent of inflammatory mediators) augment the temporal LPS response and support the notion that repeated transient oxidative stress (such as that induced by regular exercise) is important for a &amp;amp;amp;amp;amp;amp;quot;healthy&amp;amp;amp;amp;amp;amp;quot; immune system.

Research paper thumbnail of Post-Exercise Skeletal Muscle Glycogen Related to Plasma Cytokine but Not Muscle mRNA Expression

Medicine and Science in Sports and Exercise, May 1, 2015

performed the exercise bout (60%VO 2peak ; ~30-135 minutes) on a treadmill 45 minutes post-HFM (6... more performed the exercise bout (60%VO 2peak ; ~30-135 minutes) on a treadmill 45 minutes post-HFM (63% fat, 10kcal/kg of body weight). Blood lipids and exhaled nitric oxide (eNO) were measured at baseline and 2 h and 4 h post-HFM. Sputum differential cell counts were performed at baseline and 4 h post-HFM to assess airway inflammation. RESULTS: Triglycerides increased significantly in ACT CON and ACT EX 2 h (~54%, p=0.001; ~66%, p=0.013, respectively) and 4 h (~107%, p=0.001; ~119%, p=0.004, respectively) post-HFM and also IN CON at 4 h (~44%; p= 0.004) and IN EX (2 h, ~62%, p= 0.001; 4 h, ~93%, p=0.001) post-HFM. Area under the curve (AUC) was significantly lower in ACT EX (p<0.001) than ACT CON and IN EX, but was not significantly different in IN CON versus IN EX (p>0.05). Exhaled nitric oxide increased non-linearly from baseline to 2 and 4 h post-HFM in ACT (p<0.05, η 2 =0.36) and IN (<0.05), but was not dependent on condition. CONCLUSION: Preliminary findings suggest that in both active and inactive subjects, an exercise bout after a HFM did not reduce post-prandial airway inflammation. However, the exercise bout was effective in reducing PPL in active subjects, but not inactive subjects. Post-prandial airway inflammation occurred following a high-fat meal regardless of a reduction in post-prandial triglycerides.

Research paper thumbnail of The in vitro evaluation of isolated procyanidins as modulators of cytokine-induced eotaxin production in human alveolar epithelial cells

Journal of Berry Research, Jun 16, 2016

BACKGROUND: Populations that consume procyanidin-rich diets are less susceptible to inflammatory ... more BACKGROUND: Populations that consume procyanidin-rich diets are less susceptible to inflammatory disease. Allergic asthma is an inflammatory lung disease perpetuated by a hyperreactive airway epithelium and eosinophil infiltration into the lung. Eotaxin-1 (CCL11) mediates eosinophil migration into tissues and its modulation could represent a means to assist the management of airway inflammation. OBJECTIVE: Here we evaluated procyanidins as a means of modulating CCL11 production in vitro. METHODS: We used human lung epithelial cells (A549) and optimized the conditions to induce CCL11 production in vitro. Cells were exposed to procyanidins for 6 h prior to an inflammatory insult of 5 ng/mL IL-4 with 5 ng/mL TNF␣ for 48 h. An enzyme-linked immunosorbent assay was used to measure CCL11 production. RESULTS: Cells exposed to 5 M procyanidin A2 prior to the inflammatory challenge showed significantly inhibited (36%) CCL11 production. Under the same conditions, procyanidins B1 and B2 elicited no effect. Furthermore, combinations of procyanidins A2 and B2 (5 M total) demonstrated no evidence of a synergistic interaction. CONCLUSIONS: These data demonstrate that the regulation of CCL11 by lung epithelial cells is not ubiquitous among the three investigated procyanidins. We demonstrate a differential inhibition of CCL11 by A-type and B-type procyanidins. This evidence supports further studies into procyanidins, specifically A-type, for managing inappropriate airway inflammation.

Research paper thumbnail of Boysenberry and apple juice concentrate reduced acute lung inflammation and increased M2 macrophage‐associated cytokines in an acute mouse model of allergic airways disease

Food Science & Nutrition, 2021

Bioactive compounds including anthocyanins and other polyphenols are associated with reduced lung... more Bioactive compounds including anthocyanins and other polyphenols are associated with reduced lung inflammation and improved lung function in asthma and other lung diseases. This study investigated the effects of a Boysenberry and apple juice concentrate, high in cyanidin glycosides, ellagitannins, and chlorogenic acid, on a mouse model of allergic airways inflammation. Male C57BL/6J mice were orally gavaged with 2.5 mg/kg of total anthocyanins (TAC) from BerriQi® Boysenberry and apple juice concentrate (0.2 mg/kg human equivalent dose) or water control 1 hr before an acute intranasal ovalbumin (OVA) challenge and were gavaged again 2 days after the intranasal challenge. Consumption of BerriQi® Boysenberry and apple juice concentrate significantly decreased OVA‐induced infiltrating eosinophils, neutrophils, and T cells in the lung, and mucous production. Quantification of gene expression for arginase (Arg1), chitinase 3‐like 3 (Ym‐1), found in inflammatory zone (Fizz1), which have be...

Research paper thumbnail of Anthocyanin-Rich New Zealand Blackcurrant Extract Supports the Maintenance of Forearm Blood-Flow During Prolonged Sedentary Sitting

Frontiers in Nutrition, 2020

Objectives: We examined the acute effects of anthocyanin-rich New Zealand blackcurrant extract an... more Objectives: We examined the acute effects of anthocyanin-rich New Zealand blackcurrant extract and a placebo on hemodynamics during 120 min of sedentary sitting in healthy males. Additionally, we investigated whether changes in resting hemodynamics altered repeated isometric hand-grip exercise performance and post exercise forearm blood flow (FBF). Methods: Ten healthy males completed two trials during which they ingested either blackcurrant extract (1.87 mg total anthocyanins/kg bodyweight) or placebo powder. Heart rate, blood pressure and forearm blood flow were measured, and venous blood was sampled, prior to and 30, 60, 90 and 120 min-post ingestion. Participants remained seated for the duration of each trial. At 120 min post-ingestion participants completed as many repetitions of isometric hand-grip contractions as possible. Results: Heart rate, blood pressure and mean arterial pressure changed over time (all p < 0.001) but did not differ between treatments. A treatment x time interaction for FBF (p = 0.025) and forearm vascular resistance (FVR) (p = 0.002) was found. No difference in the number of isometric hand-grip contractions was observed between treatments (p = 0.68) nor was there any treatment x time interaction in post-exercise FBF (p = 0.997). Plasma endothelin-1 (p = 0.023) and nitrate (p = 0.047) changed over time but did not differ between treatments (both p > 0.1). Plasma nitrite did not change over time (p = 0.732) or differ between treatments (p = 0.373). Conclusion: This study demonstrated that acute ingestion of a single dose of blackcurrant extract maintained FBF and FVR during an extended period of sitting; however, this did not influence exercise performance during hand-grip exercise.

Research paper thumbnail of Fruits and Vegetables as Functional Foods for Exercise and Inflammation

Elsevier eBooks, 2013

Fruits and vegetables are good sources of polyphenolic compounds with antioxidant abilities, lead... more Fruits and vegetables are good sources of polyphenolic compounds with antioxidant abilities, leading to the theory that a control of oxidative stress is responsible for the health benefits of a diet rich in these foods. However, there is a lack of strong supportive data from human studies and evidence indicates that polyphenolic compounds also have anti-inflammatory and immune-modulatory activity. This chapter summarizes the evidence for the effects of polyphenolic compounds on modulating oxidative stress and inflammation with regard to exercise performance and asthma with a perspective on the usefulness of fruit and vegetables and/or derived bioactives as functional foods.

Research paper thumbnail of Muscle Glycogen Depletion Following 75-km of Cycling Is Not Linked to Increased Muscle IL-6, IL-8, and MCP-1 mRNA Expression and Protein Content

Frontiers in Physiology, 2016

The cytokine response to heavy exertion varies widely for unknown reasons, and this study evaluat... more The cytokine response to heavy exertion varies widely for unknown reasons, and this study evaluated the relative importance of glycogen depletion, muscle damage, and stress hormone changes on blood and muscle cytokine measures. Cyclists (N = 20) participated in a 75-km cycling time trial (168 ± 26.0 min), with blood and vastus lateralis muscle samples collected before and after. Muscle glycogen decreased 77.2 ± 17.4%,

Research paper thumbnail of Correction to: The effect of New Zealand blackcurrant on sport performance and related biomarkers: a systematic review and meta-analysis

Journal of the International Society of Sports Nutrition, 2021

An amendment to this paper has been published and can be accessed via the original article.

Research paper thumbnail of Effects of α-adrenergic antagonists on insulin secretion from rat pancreatic islets

Biochemical Society Transactions, 1988

Research paper thumbnail of Daily Consumption of an Anthocyanin-Rich Extract Made From New Zealand Blackcurrants for 5 Weeks Supports Exercise Recovery Through the Management of Oxidative Stress and Inflammation: A Randomized Placebo Controlled Pilot Study

Frontiers in Nutrition, 2020

Conclusions: Daily consumption of BAE for 5 weeks serves to enhance the exercise recovery effecti... more Conclusions: Daily consumption of BAE for 5 weeks serves to enhance the exercise recovery effectiveness of a single consumption of BAE and promotes beneficial/ protective antioxidant/anti-inflammatory cellular events that facilitate exercise recovery.

Research paper thumbnail of A Simple, Robust, and Convenient HPLC Assay for Urinary Lactulose and Mannitol in the Dual Sugar Absorption Test

Molecules

Background: Heterogeneous laborious analytical methodologies for the determination of urinary lac... more Background: Heterogeneous laborious analytical methodologies for the determination of urinary lactulose and mannitol limit their utility in intestinal permeability testing. Methods: We developed an assay using a Shimadzu HPLC system, an Aminex HPX87C column, and refractive index detection. The test was calibrated using a series of dilutions from standard stock solutions of lactulose and mannitol ‘spiked’ into urine samples. The utility to quantify urinary excretion during the dual sugar absorption test over 6 h was also determined. Results: Lactulose and mannitol were eluted isocratically at 5.7 and 10.1 min, respectively, with water as a mobile phase at a flow rate of 0.3 mL min−1, 858 psi, 60 °C. The calibration curves for both sugars were linear up to 500 µg mL−1 with a limit of detection in standard solutions at 4 µg mL−1 and in ‘spiked’ urine samples at 15 µg mL−1. The intra-assay and inter-assay CVs were between 2.0–5.1% and 2.0–5.1% for lactulose and 2.5–4.4% and 2.8–3.9% for...