Redox Status and Immune Function

Evidence of a Redox-dependent Regulation of Immune Responses to Exercise-Induced Inflammation

In this investigation the investigators utilized N-acetylcysteine (NAC) supplementation to enhance reduced glutathione (GSH) stores during an 8-day recovery period from a strenuous eccentric exercise protocol in order to test the hypotheses: i) redox status perturbations in skeletal muscle are pivotal for the immune responses and ii) antioxidant supplementation may alter immune cell responses following exercise-induced muscle microtrauma.

Study Overview

• Status: Completed
• Conditions: Skeletal Muscle Damage; Aseptic Inflammation; Skeletal Muscle Function
• Intervention / Treatment: Dietary supplement: n-acetylcysteine; Dietary supplement: Placebo

Detailed Description

The major thiol-disulfide couple of GSH and oxidized glutathione (GSSG) is a crucial regulator of the main transcriptional pathways regulating aseptic inflammation and recovery of skeletal muscle following aseptic injury. Antioxidant supplementation may hamper exercise-induced inflammatory responses.

The objective was to examine how thiol-based antioxidant supplementation affects immune mobilization following exercise-induced skeletal muscle microtrauma. In a two-trial, double-blind, crossover, repeated measures design, 10 young men received either placebo or NAC (20 mg/kg/day) immediately after a muscle-damaging exercise protocol (300 eccentric contractions) and for eight consecutive days. Blood sampling and performance assessment were performed pre-exercise, 2h post-exercise and daily for 8 consecutive days.

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Greece
  • Athens, Greece, 11527
    • University of Athens, Medical School, Department of Clinical Therapeutics

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 30 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Recreationally trained (VO2max > 45 ml/kg/min)
• Engaged in regular exercise for ≥3 times/week for > 12 months
• non-smokers
• Abstain from exercise during the course of the two trials
• No consumption of performance-enhancing substances, antioxidants, caffeine, alcohol and/or medications during the study.

Exclusion Criteria:

• NAC intolerance
• Recent musculoskeletal injuries of the lower limbs
• Febrile illness
• History of muscle lesion.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: CROSSOVER
• Masking: DOUBLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: n-acetylcysteine; orally in three daily dosages, at 20 mg/kg/day, daily for eight days after exercise	Dietary supplement: n-acetylcysteine; 20 mg//kg/day, orally, daily for eight days following exercise; Other Names: NAC
Active Comparator: Placebo; orally in three daily dosages, content: 500 mL drink that contained water (375 mL), sugar-free cordial (125 ml), and 2 g of low-calorie glucose/dextrose powder	Dietary supplement: Placebo; 500 mL orally, daily for eight days following exercise

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in protein carbonyls in red blood cells	Concentration of protein carbonyls	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in thiobarbituric acid reactive substances in red blood cells	Thiobarbituric acid reactive substances concentration in red blood cells	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in total antioxidant capacity in serum		Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in reduced glutathione in blood	Concentration of reduced glutathione in red blood cells	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in oxidized glutathione in blood	Concentration of oxidized glutathione in red blood cells	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in catalase activity in red blood cells		Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in creatine kinase activity in serum		Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in high sensitivity C-reactive protein in serum		Pre-exercise, 2 hours post-exercise, 1 day post-exercise, 2 days post-exercise, 3 days post-exercise
Changes in white blood cell count in blood		Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in adhesion molecule concentration in blood	Measurement of soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble intercellular cell adhesion molecule-1 (sICAM-1) concentrations in plasma	Pre-exercise, 2 hours post-exercise, 1 day post-exercise, 2 days post-exercise, 3 days post-exercise
Changes in cytokine concentration in serum	Measurement of interleukin-1β (IL-1β) and interleukin-6 (IL-6)	Pre-exercise, 2 hours post-exercise, 1 day post-exercise, 2 days post-exercise, 3 days post-exercise, 8 days post-exercise
Changes in neutrophil count in blood	Cytofluorometric analysis of neutrophil count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in lymphocyte count in blood	Cytofluorometric analysis of lymphocyte count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in monocyte count in blood	Cytofluorometric analysis of monocyte count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in basophil count in blood	Cytofluorometric analysis of baseophil count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in eosinophil count in blood	Cytofluorometric analysis of eosinophil count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in T-helper cell count in blood	Cytofluorometric analysis of T-helper cell count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in T cytotoxic cell count in blood	Cytofluorometric analysis of T cytotoxic cell count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in natural killer-T (NK-T) cell count in blood	Cytofluorometric analysis of NK-T cell count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in 62L macrophage count in blood	Cytofluorometric analysis of 62L macrophage count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in B lympho cell count in blood	Cytofluorometric analysis of B lympho cell count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in natural killer (NK) cell count in blood	Cytofluorometric analysis of natural killer cell count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in macrophage count in blood	Cytofluorometric analysis of macrophage count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in HLA+/Macr+ macrophage count in blood	Cytofluorometric analysis of HLA+/Macr+ count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in 11B+ macrophage count in blood	Cytofluorometric analysis of 11B+ macrophage count in blood	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximal aerobic capacity	Assessment of maximal oxygen consumption	One day before exercise
Changes in muscle performance	Assessment of maximal knee extensor eccentric peak torque on an isokinetic dynamometer at 60o/s.	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Changes in delayed onset of muscle soreness	Assessment of the delayed onset of muscle soreness by palpation of the vastus lateralis and rectus femoris following a squat motion	Pre-exercise, 2 hours post-exercise, daily for 8 consecutive days post-exercise
Body composition	Measurement of body composition by Dual Emission X-ray Absorptiometry (DXA)	One day before exercise
Changes in dietary intake profile	Assessment of dietary intake with emphasis on antioxidant element intake	One day before exercise and daily for 8 consecutive days post-exercise

Collaborators and Investigators

• Sponsor: National and Kapodistrian University of Athens
• Investigators: Study Director: Asimina Mitrakou, Associate Prof., Department of Diabetes and Metabolism Unit of the Department of Clinical Therapeutics, National and Kapodistrian University of Athens

Study record dates

Study Major Dates

• Study Start: January 1, 2015
• Primary Completion (Actual): February 1, 2016
• Study Completion (Actual): March 1, 2016

Study Registration Dates

• First Submitted: October 4, 2016
• First Submitted That Met QC Criteria: October 7, 2016
• First Posted (Estimate): October 11, 2016

Study Record Updates

• Last Update Posted (Estimate): October 11, 2016
• Last Update Submitted That Met QC Criteria: October 7, 2016
• Last Verified: October 1, 2016

More Information

Terms related to this study

• Keywords: exercise; immune cells; redox status; muscle injury
• Additional Relevant MeSH Terms: Pathologic Processes; Inflammation; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Anti-Infective Agents; Antiviral Agents; Protective Agents; Respiratory System Agents; Antioxidants; Antidotes; Free Radical Scavengers; Expectorants; Acetylcysteine; N-monoacetylcystine
• Other Study ID Numbers: NACEXERCISE2016