Effects of distance running and subsequent intake of glutamine rich peptide on biomedical parameters of male Japanese athletes

Immunostimulant plant proteins: Potential candidates as vaccine adjuvants

The COVID-19 pandemic is shaking up global scientific structures toward addressing antibiotic resistance threats and indicates an urgent need to develop more cost-effective vaccines. Vaccine adjuvants play a crucial role in boosting immunogenicity and improving vaccine efficacy. The toxicity and adversity of most adjuvant formulations are the major human immunization problems, especially in routine pediatric and immunocompromised patients. The present review focused on preclinical studies of immunoadjuvant plant proteins in use with antiparasitic, antifungal, and antiviral vaccines. Moreover, this report outlines the current perspective of immunostimulant plant protein candidates that can be used by researchers in developing new generations of vaccine-adjuvants. Future clinical studies are required to substantiate the plant proteins' safety and applicability as a vaccine adjuvant in pharmaceutical manufacturing.

The effect of glutamine supplementation on athletic performance, body composition, and immune function: A systematic review and a meta-analysis of clinical trials

BACKGROUND & AIM

This systematic review and meta-analysis of available evidence was conducted to obtain a conclusive result on the effects of glutamine supplementation on athletes.

METHODS

Systematic review and meta-analysis. Data related to body mass, lean body mass, body fat percentage, Vo2 max, lymphocytes, leukocytes and neutrophil counts were extracted to determine the effects of GLN on performance outcomes.

DATA SOURCES

The literature search was conducted across the databases Pubmed, Scopus, ISI Web of Science, SID (Scientific Information Database) and Cochrane Central Register of Controlled Trials, covering a period up to January 2017.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Clinical trials evaluating glutamine supplementation outcomes on athletes aged over 18 were included.

RESULTS

A total of 47 studies were included in the systematic review, and 25 trials matched the inclusion criteria for the meta-analysis. According to the meta-analysis, glutamine has a significant effect on weight reduction (WMD = -1.36 [95% CI: -2.55 to -0.16], p = 0.02). Moreover, neutrophil numbers were reduced following glutamine intake at doses greater than 200 mg/kg body weight (WMD = -605.77 [95% CI: -1200.0 to 52.1]; P = 0.03). Also, supplementation by glutamine dipeptide resulted in higher blood glucose after exercise (WMD = 0.51 [95% CI: 0.18, 0.83] mmol/l; P = 0.002). There was no association between glutamine ingestion and other outcomes investigated.

CONCLUSION

According to this meta-analysis, generally, glutamine supplementation has no effect on athletics immune system, aerobic performance, and body composition. However, the current study showed that glutamine resulted in greater weight reduction. In addition, the present study suggests that the efficacy of glutamine supplementation on neutrophil numbers could be affected by supplement type and dose.

Production of a novel wheat gluten hydrolysate containing dipeptidyl peptidase-IV inhibitory tripeptides using ginger protease

Wheat gluten is a Pro-rich protein complex comprising glutenins and gliadins. Previous studies have reported that oral intake of enzymatic hydrolysates of gluten has beneficial effects, such as suppression of muscle injury and improvement of hepatitis. Here, we utilized ginger protease that preferentially cleaves peptide bonds with Pro at the P2 position to produce a novel type of wheat gluten hydrolysate. Ginger protease efficiently hydrolyzed gluten, particularly under weak acidic conditions, to peptides with an average molecular weight of <600 Da. In addition, the gluten hydrolysate contained substantial amounts of tripeptides, including Gln-Pro-Gln, Gln-Pro-Gly, Gln-Pro-Phe, Leu-Pro-Gln, and Ser-Pro-Gln (e.g. 40.7 mg/g at pH 5.2). These gluten-derived tripeptides showed high inhibitory activity on dipeptidyl peptidase-IV with IC50 values of 79.8, 70.9, 71.7, 56.7, and 78.9 μM, respectively, suggesting that the novel gluten hydrolysate prepared using ginger protease can be used as a functional food for patients with type 2 diabetes.

Food-derived immunomodulatory peptides

Food proteins contain specific amino acid sequences within their structures that may positively impact bodily functions and have multiple immunomodulatory effects. The functional properties of these specific sequences, also referred to as bioactive peptides, are revealed only after the degradation of native proteins during digestion processes. Currently, milk proteins have been the most explored source of bioactive peptides, which presents an interesting opportunity for the dairy industry. However, plant- and animal-derived proteins have also been shown to be important sources of bioactive peptides. This review summarizes the in vitro and in vivo evidence of the role of various food proteins as sources of immunomodulatory peptides and discusses the possible pathways involving these properties. © 2016 Society of Chemical Industry.

Wheat gluten hydrolysate affects race performance in the triathlon

Wheat gluten hydrolysate (WGH) is a food ingredient, prepared by partial enzymatic digestion of wheat gluten, which has been reported to suppress exercise-induced elevation of serum creatinine kinase (CK) activity. However, its effects on athletic performance have not yet been elucidated. This is the presentation of an experiment performed on five female college triathletes who completed an Olympic distance triathlon with or without ingestion of 21 g of WGH during the cycling leg. The experiment was performed in a crossover double-blind manner. The race time of the running leg and thus the total race time was significantly shorter when WGH was ingested. However, serum CK levels exhibited no apparent differences between the two WGH or placebo groups.

A randomised, blinded, crossover study to assess the efficacy of a feed supplement in alleviating the clinical signs of headshaking in 32 horses

REASONS FOR PERFORMING STUDY

Feed supplements are commonly used by owners to alleviate headshaking; however, randomised, controlled trials are required to assess their efficacy.

OBJECTIVE

To determine the efficacy of a feed supplement for alleviation of the clinical signs of headshaking using a randomised, blinded, placebo-controlled trial.

METHODS

Using a crossover design, 44 horses previously diagnosed with chronic idiopathic headshaking received both the supplement and a matching placebo per os for 28 days with a washout period between of 14 days. Video recordings were taken at rest and exercise prior to the study and at the end of both periods of treatment. The degree of headshaking was assessed in a blinded, randomised manner by 2 veterinary surgeons. At the same time points, owners completed a questionnaire to assess the severity of headshaking signs. A Wilcoxon signed rank test was used to compare the scores while on supplement and placebo.

RESULTS

Using the video assessments, there was no significant difference between scores while on supplement compared with placebo (P = 0.7). Using the questionnaire responses, there was no significant difference between scores for any activity when the placebo and the supplement were compared with each other. However, owners reported significant improvement during all activities for both placebo and supplement compared with pretreatment scores.

CONCLUSIONS AND POTENTIAL RELEVANCE

The supplement offered no benefit over a placebo in alleviating the clinical signs of headshaking. There appeared to be a significant proxy placebo effect when the outcome was based on subjective owner perception of clinical signs. This study demonstrated no beneficial effect of this supplement on the clinical signs of headshaking. The study did show a significant placebo effect, thereby highlighting the necessity of properly conducted, randomised controlled trials, with blinding, to assess true treatment effects in trials in animals.

Female distance runners show a different response to post-workout consumption of wheat gluten hydrolysate compared to their male counterparts

Wheat gluten hydrolysate (WGH) is rich in glutamyl residue; glutamine is considered a conditionally essential amino acid under physical stress. WGH has been reported to suppress post-exercise rises in serum creatine kinase in male distance runners. This study aimed to reproduce the effects in female distance runners under similar conditions. The study was conducted in a double-blinded crossover manner. Six female collegiate distance runners ingested WGH or a placebo after a 2-h run at an intensity estimated as 60-70% of their maximum oxygen uptake. Blood was sampled before, immediately after, and at 10 and 24 h after the run. Unlike those in male runners, serum creatine kinase (CK) increased slightly, with a peak at 10 h after the run, while plasma glutamine kept declining. The anti-inflammatory effect of WGH was not evident since the post-exercise elevation of CK was ambiguous. Plasma glutamine concentrations also showed a different kinetics from that in men.

Post-training consumption of wheat gluten hydrolysate suppresses the delayed onset of muscle injury in soccer players

Wheat gluten hydrolysate (WGH) is reported to suppress the muscle injuries associated with exercise in long distance running and weight training. In the present study, we investigated the effects of WGH consumption on suppression of muscle injury after soccer training in a double-blind crossover study. Immediately after a mini soccer game, six soccer players consumed 18.0 g of WGH, and muscle injury was investigated using serum creatine kinase (CK) as an indicator. The results showed a significant increase in serum CK from immediately after exercise to 12 h after exercise stress (p<0.05) in the placebo group, while serum CK decreased during this same time period in the WGH group, and the difference between the two groups was significant. This suggests that WGH consumption suppresses delayed-onset muscle injury after exercise in soccer.

Delayed-onset muscle injury and its modification by wheat gluten hydrolysate

OBJECTIVE

We investigated the pattern of delayed-onset muscle injury in well-trained athletes after a competitive half-marathon and the effects of post-race intake of wheat gluten hydrolysate (WGH).

METHODS

Thirty well-trained college runners with a best time of 14-15 min over 5000 m raced in a half-marathon. Thereafter, they were divided into three groups based on finish times and given 0 (control), 10, or 20 g of WGH. Blood biochemical parameters were monitored at -1 d, +1 h, +1 d, and +2 d after the race. Data selected according to finish times and biochemical parameters were then analyzed.

RESULTS

Plasma creatine kinase activity peaked at 1 d after the race in the control group and correlated with post-race white blood cell counts. The post-race elevation of creatine kinase activity was dose-dependently suppressed by WGH.

CONCLUSION

Delayed-onset muscle injury peaked in well-trained distance runners at 1 d after a half-marathon and was dose-dependently suppressed by a post-race intake of WGH.