Public opinions on disclosure of tobacco components: Results of a nationwide cross-sectional survey in Republic of Korea

This study aimed to explore public views on disclosure of tobacco components in an effort to develop a comprehensive regulatory system facilitating implementation of the Framework Convention on Tobacco Control (FCTC) Articles 9 and 10 in Korea.In all, 1200 representative Koreans 19 years old or older were enrolled and information on their general characteristics, smoking status, awareness of the effects of smoking on health, and views on the public disclosure of tobacco components was collected by telephone using a structured questionnaire. Factors associated with acceptance of the need for public disclosure of tobacco components were identified via multivariate analysis.Most participants considered it necessary to publicly disclose tobacco components (95.9%) and were aware of the risk to health posed by smoking (76.0%). The prevalent view was that tobacco companies should be legally required to publicly disclose details of the components of cigarettes, their levels per cigarette, and their effects on health. The most effective means of disclosure were considered to be the mass media, printed materials, and labels on cigarette packs. Females and never-smokers (odds ratio [OR]: 4.39, 95% confidence interval [95% CI]: 1.76-10.94) more readily accepted the need for public disclosure, whereas those of lower educational level and/or who were less aware of the harm to health posed by smoking (OR: 0.05, 95% CI: 0.01-0.18) were less likely to be accepting.The attitude of the general population ensures that FCTC Articles 9 and 10 will be successfully implemented in Korea. Further public consultation on the details of disclosure would be useful for the development of a comprehensive regulatory system.

Production of starch nanoparticles using normal maize starch via heat-moisture treatment under mildly acidic conditions and homogenization

Normal maize starch was subjected to heat-moisture treatment (HMT) under mildly acidic conditions (0.000, 0.050, or 0.075M H2SO4) for various treatment times (3, 5, or 8h) followed by homogenization up to 60min to prepare nanoparticles. The combination of HMT (0.075M, for 8h) and homogenization (60min) produced nanoparticles with diameters of less than 50nm at a yield higher than 80%. X-ray diffractometry and size-exclusion chromatography revealed that HMT under mildly acidic conditions selectively hydrolyzed the starch chains (especially amylose and/or long chains of amylopectin) in the amorphous region of the granules without significant damage to the crystalline structure, however, modification of the molecular structure in the amorphous region increased fragility of the granules during homogenization. Homogenization for 60min caused obvious damage in the long-range crystalline structure of the HMT starch (0.15N, for 8h), while the short-range chain associations (FT-IR) remained intact.

Blockade of interleukin-8 receptor signalling inhibits cyst development in vitro, via suppression of cell proliferation in autosomal polycystic kidney disease

AIM

Autosomal dominant polycystic kidney disease (ADPKD) is a highly prevalent inherited disorder and results in the progressive development of cysts in both kidneys. In recent studies, several cytokines and growth factors secreted by the cyst-lining epithelia were identified to be upregulated and promote cyst growth. According to our previous study, chemokines with a similar amino acid sequence as human interleukin-8 (IL-8) are highly expressed in a rodent model with renal cysts. Therefore, in this study, we focused on whether IL-8 signalling is associated with renal cyst formation, and tested the possibility of IL-8 as a new therapeutic target for ADPKD.

METHODS

Expression of IL-8 and its receptor were screened either by enzyme linked immunosorbent assay (ELISA) or Western blot. Inhibited IL-8 signalling by antagonist for IL-8 receptor or gene silencing was tested in molecular levels, mainly through Western blot. And cell proliferation was measured by XTT assays. Finally, a three-dimensional culture was performed to understand how IL-8 affected cyst formation, in vitro.

RESULTS

Interleukin-8 secretion and expression of its receptor highly increased in two different human ADPKD cell lines (WT9-7 and WT9-12), compared to normal human renal cortical epithelial cell line. Cell proliferation, which is mediated by IL-8 signal, was inhibited either by an antagonist or siRNA targeting for IL-8 receptor. Finally, a three-dimensional culture showed an alleviation of cystogenesis in vitro, after blocking the IL-8 receptor signals.

CONCLUSION

These results suggest that IL-8 and its signalling molecules could be new biomarkers and a therapeutic target of ADPKD.

Comparison of remifentanil with dexmedetomidine for monitored anaesthesia care in elderly patients during vertebroplasty and kyphoplasty

OBJECTIVES

This clinical trial is registered at ClinicalTrials.gov. (NCT02476981)This randomized, prospective double-blind study compared remifentanil with dexmedetomidine for monitored anaesthesia care during minimally invasive corrections of vertebral compression fractures (vertebroplasty or kyphoplasty).

METHODS

Patients > 65 years of age with American Society of Anesthesiologists (ASA) classification I-III, scheduled for vertebroplasty or kyphoplasty under monitored anaesthesia care, received remifentanil (i.v. infusion 1-5 µg/kg/h) or dexmedetomidine (loading dose 0.3-0.4 µg/kg followed by i.v. infusion 0.2-1 µg/kg/h) to maintain observer's assessment of alertness/sedation (OAA/S) scale <4 during the procedure.

RESULTS

There were no statistically significant differences in demographic data between the remifentanil (n = 37) and dexmedetomidine groups (n = 38). Patients on dexmedetomidine experienced lower mean arterial pressure (MAP) and heart rate (HR), and higher SpO2 values, than patients on remifentanil. Compared with dexmedetomidine, remifentanil produced more respiratory depression, oxygen desaturation, and reduced the need for additional intraoperative opioids. There were no significant between-group differences in terms of recovery time, investigators' satisfaction scores, or patients' overall pain experiences.

CONCLUSIONS

During monitored anaesthesia care, dexmedetomidine provides less respiratory depression, lower MAP and HR, but also less analgesic effect than remifentanil in elderly patients undergoing vertebroplasty or kyphoplasty.

The effects of PEP-1-FK506BP on dry eye disease in a rat model

As FK506 binding proteins (FK506BPs) are known to play an important role in the regulation of a variety of biological processes related to cell survival, this study was designed to examined the protective effects of FK506 binding protein 12 (FK506BP) on low humidity air flow induced dry eye in a rat model using transduced PEP-1-FK506BP. After the topical application of PEP-1-FK506BP, tear volumes were markedly increased and significant prevention of cornea damage was observed compared with dry eye rats. Further, immunohistochemical analysis demonstrated that PEP-1-FK506BP markedly prevented damage to the cornea, the bulbar conjunctiva, and the palpebral conjunctiva epithelial lining compared with dry eye rats. In addition, caspase-3 and PARP expression levels were found to be decreased. These results demonstrated that topical application of PEP-1-FK506BP significantly ameliorates dry eye injury in an animal model. Thus, we suggest that PEP-1-FK506BP can be developed as a new ophthalmic drop to treat dry eye diseases.

Epigenetic silencing of the MUPCDH gene as a possible prognostic biomarker for cyst growth in ADPKD

Although autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disease, and is characterized by the formation of multiple fluid-filled cysts, which results in renal failure, early diagnosis and treatment of ADPKD have yet to be defined. Herein, we observed that the promoter region of the gene encoding mucin-like protocadherin (MUPCDH) was hypermethylated in the renal tissue of patients with ADPKD compared to non-ADPKD controls. Inversely, MUPCDH was significantly repressed in ADPKD, especially in cyst-lining cells. Our results indicate that aberrant methylation of MUPCDH promoter CpG islands may be negatively correlated with reduced expression level of MUPCDH and that this contributes to abnormal cell proliferation in ADPKD. It suggests that methylation status of MUPCDH promoter can be used as a novel epigenetic biomarker and a therapeutic target in ADPKD.

Investigation of psychometric properties of the Falls Efficacy Scale using Rasch analysis in patients with hemiplegic stroke

[Purpose] The purpose of this study was to investigate the psychometric properties of the Falls Efficacy Scale using Rasch analysis in patients with hemiplegic stroke. [Subjects] Fifty-five community-dwelling hemiplegic stroke patients were selected as participants. [Methods] Data were analyzed using the Winsteps program (version 3.62) with the Rasch model to confirm the unidimensionality through item fit, reliability, and appropriateness of the rating scale. [Results] There were no misfit persons or items. Furthermore, infit and outfit statistics appeared adjacent. The person separation value was 3.07, and the reliability coefficient was 0.90. The reliability of all items was at an acceptable level for patients with hemiplegic stroke. [Conclusion] This was the first study to investigate the psychometric properties of the Falls Efficacy Scale using Rasch analysis. The results of this study suggest that the 6-point Falls Efficacy Scale is an appropriate tool for measuring the self-perceived fear of falling in patients with hemiplegic stroke.

Experiences with, perceptions of and attitudes towards traditional Korean medicine (TKM) in patients with chronic fatigue: a qualitative, one-on-one, in-depth interview study

OBJECTIVES

To explore perceptions and experiences of patients with chronic fatigue with traditional Korean medicine (TKM) and their motivation for choosing TKM.

DESIGN

Qualitative, one-on-one, in-depth interview study.

SETTING

Primary TKM hospitals in Seoul, Incheon and Daejeon, South Korea.

RESULTS

15 patients with chronic fatigue were interviewed in this study. Patients with chronic fatigue experienced physical and psychological symptoms that resulted in severe difficulties associated with routine daily activities. The motivations for choosing TKM were primarily dissatisfaction with conventional medicine and previous positive experiences with TKM. While undergoing TKM treatment, patients found that TKM practitioners considered fatigue to be a treatable illness; also, patients felt comfortable with the doctor-patient relationship in TKM.

CONCLUSIONS

Healthcare providers need to be concerned about the symptoms of chronic fatigue to a degree that is in line with the patient's own perceptions. Korean patients with chronic fatigue choose TKM as an alternative to fulfil their long-term needs that were unmet by conventional medicine, and they are greatly positively influenced by TKM. TKM may present a possible therapy to alleviate symptoms of diseases that conventional medicine does not address and is an approach that has a considerable effect on Korean patients.

Scientific Evidence Supporting Policy Change: A Study on Secondhand Smoke Exposure in Non-smoking Areas of PC Rooms in Korea

Purpose

The objective of this study was to measure secondhand smoke (SHS) exposure in personal computer (PC) rooms with the purpose of determining the strength of scientific evidence supporting the legislative ban on smoking in PC rooms located in the Republic of Korea.

Materials and Methods

From June to September 2012, particulate matter (PM_2.5) and air nicotine concentration (ANC) were measured in the smoking and non-smoking areas of PC rooms in Goyang City, Korea. In 28 randomly sampled PC rooms, field investigators completed an observational questionnaire on building characteristics, smoking policies, and evidence of smoking. The geometric means (GM) of PM_2.5 and ANC in smoking and non-smoking areas were compared.

Results

Evidence of smoking was identified in both the smoking and non-smoking areas of all PC rooms. The GMs of PM_2.5 and ANC in both areas were high and did not differ significantly (174.77 μg/m³ and 48.95 μg/m³ in smoking areas; 93.38 μg/m³ and 41.30 μg/m³ in non-smoking areas). Overall PM_2.5 concentrations were 5.5-fold higher than those listed in the World Health Organization guidelines.

Conclusion

This study supported previous reports that a partial smoking ban did not protect individuals from SHS exposure. Furthermore, the results from our study suggest how research can support policy. Countries in which smoke-free policies are not yet comprehensive may find our results useful.

Inhibition of Aerobic Glycolysis Represses Akt/mTOR/HIF-1α Axis and Restores Tamoxifen Sensitivity in Antiestrogen-Resistant Breast Cancer Cells

Tamoxifen resistance is often observed in the majority of estrogen receptor–positive breast cancers and it remains as a serious clinical problem in breast cancer management. Increased aerobic glycolysis has been proposed as one of the mechanisms for acquired resistance to chemotherapeutic agents in breast cancer cells such as adriamycin. Herein, we report that the glycolysis rates in LCC2 and LCC9—tamoxifen-resistant human breast cancer cell lines derived from MCF7— are higher than those in MCF7S, which is the parent MCF7 subline. Inhibition of key glycolytic enzyme such as hexokinase-2 resulted in cell growth retardation at higher degree in LCC2 and LCC9 than that in MCF7S. This implies that increased aerobic glycolysis even under O₂-rich conditions, a phenomenon known as the Warburg effect, is closely associated with tamoxifen resistance. We found that HIF-1α is activated via an Akt/mTOR signaling pathway in LCC2 and LCC9 cells without hypoxic condition. Importantly, specific inhibition of hexokinase-2 suppressed the activity of Akt/mTOR/HIF-1α axis in LCC2 and LCC9 cells. In addition, the phosphorylated AMPK which is a negative regulator of mTOR was decreased in LCC2 and LCC9 cells compared to MCF7S. Interestingly, either the inhibition of mTOR activity or increase in AMPK activity induced a reduction in lactate accumulation and cell survival in the LCC2 and LCC9 cells. Taken together, our data provide evidence that development of tamoxifen resistance may be driven by HIF-1α hyperactivation via modulation of Akt/mTOR and/or AMPK signaling pathways. Therefore, we suggest that the HIF-1α hyperactivation is a critical marker of increased aerobic glycolysis in accordance with tamoxifen resistance and thus restoration of aerobic glycolysis may be novel therapeutic target for treatment of tamoxifen-resistant breast cancer.

Factors Related to Relapse After 6 Months of Smoking Cessation Among Men in the Republic of Korea: A Cross-Sectional Study

We identified factors associated with relapse after 6 months of smoking cessation (late relapse) among males of the Republic of Korea. Of the 222,707 smokers who visited public health center-based smoking cessation clinics (SCCs) between January 1, 2009 and mid-December 2009, we included 1720 individuals who successfully completed a 6-month smoking cessation program at an SCC. These participants were selected via a random stratified sampling design and completed an SCC user satisfaction survey between December 31, 2009 and January 6, 2010. Multiple logistic regression was used to identify factors associated with late relapse, and path analysis was employed to explore relationships among these factors. The frequency of late relapse was 21.6% (n = 372). Residence in a metropolitan area, low socioeconomic status, and the use of nicotine replacement therapy (NRT) were associated with statistically significant increases in late relapse, whereas greater access to counseling and more satisfaction with the SCC were associated with reduced late relapse. The path analysis showed that a greater number of cigarettes smoked daily and a younger age at smoking initiation exerted significant indirect effects on late relapse when NRT was employed. Residence in a metropolitan area indirectly prevented late relapse as counseling frequency increased. NRT use, counseling frequency, and SCC user satisfaction were affected by both smoking behavior and socioeconomic status. Relapse prevention efforts should concentrate on increasing both counseling frequency and SCC user satisfaction. Future studies should focus on the effect of NRT on the maintenance of long-term cessation at the population level in real-world settings.

What predicts the trust of online health information?

OBJECTIVES:

Little attention has been paid to levels of trust in online sources of health information. The objective of this study was to investigate levels of trust in various sources of health information (interpersonal channels, traditional media, and Internet media), and to examine the predictors of trust in health information available on the Internet.

METHODS:

A questionnaire was administered to 1,300 people (20 years of age or older), evaluating levels of trust in various sources of health information.

RESULTS:

The highest level of trust was expressed regarding interpersonal channels, with hospital physicians regarded as the most trusted source of information age and income showed an association with trust in online information sources. Elderly people were not likely to trust Internet news sources, and high incomes were found to be strongly associated with trust in online sources of information overall.

CONCLUSIONS:

Public health organizations must consider the predictors for trust in various sources of information in order to employ appropriate media when targeting vulnerable individuals or developing messaging strategies for health professionals.

PTK7+ Mononuclear Cells Express VEGFR2 and Contribute to Vascular Stabilization by Upregulating Angiopoietin-1

OBJECTIVE

In angiogenesis, circulating mononuclear cells are recruited to vascular lesions; however, the underlying mechanisms are poorly understood.

APPROACH AND RESULTS

Here, we characterize the functional role of protein tyrosine kinase 7 (PTK7)-expressing CD11b(+) mononuclear cells in vitro and in vivo using a mouse model of angiogenesis. Although the frequencies of PTK7(+)CD11b(+) cells in the bone marrow remained similar after vascular endothelial growth factor-A-induced neovascularization, we observed an 11-fold increase in the cornea. Importantly, vascular endothelial growth factor-A-induced chemotaxis of PTK7(+) cells was mediated by vascular endothelial growth factor receptor 2. In a coculture with endothelial cells, PTK7(+)CD11b(+) cells stabilized the vascular network for 2 weeks by expressing high levels of angiopoietin-1. The enhanced vascular stability was abolished by knockdown of angiopoietin-1 in PTK7(+)CD11b(+) cells and could be restored by angiopoietin-1 treatment.

CONCLUSIONS

We conclude that PTK7 expression in perivascular mononuclear cells induces vascular endothelial growth factor receptor 2 and angiopoietin-1 expression and thus contributes to vascular stabilization in angiogenesis.

Consequences of Incomplete Smoke-Free Legislation in the Republic of Korea: Results from Environmental and Biochemical Monitoring: Community Based Study

Purpose

In some countries with high smoking prevalence, smoke-free legislation has only been implemented in specific public places, as opposed to a comprehensive ban on smoking in all public places. The purpose of this study was to provide valid data on second-hand smoke (SHS) exposure that reflect the consequences of incomplete smoke-free legislation, and provide a rationale for expanding this legislation.

Materials and Methods

Indoor and outdoor environmental exposure (fine particulate matter [PM_2.5], air nicotine, and dust 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone [NNK]) was monitored in 35 public places where smoking is prohibited by law in Goyang, Republic of Korea. Biomarkers of SHS exposure (urinary cotinine, hair nicotine, and urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol) were measured in 37 non-smoking employees. Geometric means and standard deviations were used in comparison of each measure.

Results

Considerable exposure of SHS was detected at all indoor monitoring sites (PM_2.5, 95.5 μg/m³ in private educational institutions; air nicotine, 0.77 μg/m³ in large buildings; and dust NNK, 160.3 pg/mg in large buildings); environmental measures were higher in private or closed locations, such as restrooms. Outdoor measures of SHS exposure were lowest in nurseries and highest in government buildings. Biochemical measures revealed a pattern of SHS exposure by monitoring site, and were highest in private educational institutions.

Conclusion

The evidence of SHS exposure in legislative smoke-free places in Korea suggests that incomplete smoke free legislation and lack of enforcement of it might not protect people from exposure to smoke. Therefore, active steps should be taken toward a comprehensive ban on smoking in all public places and its enforcement.

Soluble receptor for advanced glycation end products inhibits disease progression in autosomal dominant polycystic kidney disease by down-regulating cell proliferation

Autosomal polycystic kidney disease (ADPKD) is a highly prevalent genetic renal disorder in which epithelial-lining fluid-filled cysts appear in kidneys. It is accompanied by hyperactivation of cell proliferation, interstitial inflammation, and fibrosis around the cyst lining cells, finally reaching end-stage renal disease. Previously, we found high expression of ligands stimulating the receptor for advanced glycation end products (RAGE) in ADPKD mice. Furthermore, gene silencing of RAGE was revealed to cause reduction of cystogenesis via down-regulation of cell proliferation in vitro, and intravenous administration of anti-RAGE adenovirus in vivo also displayed alleviation of the disease. Here, we attempted to identify the role of soluble RAGE (sRAGE) in inhibiting the progression of ADPKD using 2 different ADPKD mouse models. sRAGE is an endogenously expressed form of RAGE that has no membrane-anchoring domain, thereby giving it the ability to neutralize the ligands that stimulate RAGE signals. Both overexpression of sRAGE and sRAGE treatment blocked RAGE-mediated cell proliferation in vitro. In addition, sRAGE-injected ADPKD mice showed reduced cysts accompanied by enhanced renal function, inhibition of cell proliferation, inflammation, and fibrosis. These positive therapeutic effects of sRAGE displayed little liver toxicity, suggesting it as a new potential therapeutic target of ADPKD with low side effects.

Perceptions of cancer risk and cause of cancer risk in korean adults

PURPOSE

The aims of the present study were to assess the prevalence of perceived risk for cancer; to explore associations between sociodemographics and family history of cancer and perceived cancer risk; to identify perceived cause of cancer risk; and to examine the associations between sociodemographics and family history of cancer and perceived cause of cancer risk.

MATERIALS AND METHODS

This cross-sectional study was conducted among 1,009 participants aged 30-69 years, selected from a population-based database in October 2009 through multiple-stratified random sampling. Information was collected about the participants' perceived cancer risk and perceived cause of cancer risk.

RESULTS

Overall, 59.5% of the respondents thought they had the chance of developing cancer. Female sex, younger age, lower income, and family history of cancer were positively associated with perceived cancer risk. The most important perceived cause of cancer risk was stress. There was a difference between sociodemographics and family history of cancer and perceived cause of cancer risk.

CONCLUSION

Factors affecting perceptions of cancer risk and cause of cancer risk need to be addressed in risk communications. The results provide important directions for the development of educational strategies to promote awareness and self-appraisal of cancer risk and risk factors.

The effects of PEP-1-FK506BP on dry eye disease in a rat model

As FK506 binding proteins (FK506BPs) are known to play an important role in the regulation of a variety of biological processes related to cell survival, this study was designed to examined the protective effects of FK506 binding protein 12 (FK506BP) on low humidity air flow induced dry eye in a rat model using transduced PEP-1-FK506BP. After the topical application of PEP-1-FK506BP, tear volumes were markedly increased and significant prevention of cornea damage was observed compared with dry eye rats. Further, immunohistochemical analysis demonstrated that PEP-1-FK506BP markedly prevented damage to the cornea, the bulbar conjunctiva, and the palpebral conjunctiva epithelial lining compared with dry eye rats. In addition, caspase-3 and PARP expression levels were found to be decreased. These results demonstrated that topical application of PEP-1-FK506BP significantly ameliorates dry eye injury in an animal model. Thus, we suggest that PEP-1-FK506BP can be developed as a new ophthalmic drop to treat dry eye diseases.

Protective Effects of Quercetin Against HgCl₂-Induced Nephrotoxicity in Sprague-Dawley Rats

Mercury is a well-known environmental pollutant that can cause nephropathic diseases, including acute kidney injury (AKI). Although quercetin (QC), a natural flavonoid, has been reported to have medicinal properties, its potential protective effects against mercury-induced AKI have not been evaluated. In this study, the protective effect of QC against mercury-induced AKI was investigated using biochemical parameters, new protein-based urinary biomarkers, and a histopathological approach. A 250 mg/kg dose of QC was administered orally to Sprague-Dawley male rats for 3 days before administration of mercury chloride (HgCl2). All animals were sacrificed at 24 h after HgCl2 treatment, and biomarkers associated with nephrotoxicity were measured. Our data showed that QC absolutely prevented HgCl2-induced AKI, as indicated by biochemical parameters such as blood urea nitrogen (BUN) and serum creatinine (sCr). In particular, QC markedly decreased the accumulation of Hg in the kidney. Urinary excretion of protein-based biomarkers, including clusterin, kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), monocyte chemoattractant protein-1 (MCP-1), tissue inhibitor of metalloproteinases 1 (TIMP-1), and vascular endothelial growth factor (VEGF) in response to HgCl2 administration were significantly decreased by QC pretreatment relative to that in the HgCl2-treated group. Furthermore, urinary excretion of metallothionein and Hg were significantly elevated by QC pretreatment. Histopathological examination indicated that QC protected against HgCl2-induced proximal tubular damage in the kidney. A TUNEL assay indicated that QC pretreatment significantly reduced apoptotic cell death in the kidney. The administration of QC provided significant protective effects against mercury-induced AKI.

Glutathione supplementation suppresses muscle fatigue induced by prolonged exercise via improved aerobic metabolism

Backgrounds

Glutathione is an endogenous redox couple in animal cells and plays important roles in antioxidant defense and detoxification, although it is unknown if oral glutathione supplementation affects exercise-induced physiological changes. The present study investigated the effect of glutathione intake on exercise-induced muscle metabolism and fatigue in mice and humans.

Methods

ICR mice were divided into 4 groups: sedentary control, sedentary supplemented with glutathione (2.0%, 5 μL/g body weight), exercise control, and exercise supplemented with glutathione. After 2 weeks, the exercise groups ran on a treadmill at 25 m/min for 30 min. Immediately post-exercise, intermuscular pH was measured, and hind limb muscle and blood samples were collected to measure biochemical parameters. In a double-blind, cross-over study, 8 healthy men (35.9 ± 2.0 y) were administered either glutathione (1 g/d) or placebo for 2 weeks. Then, they exercised on a cycle ergometer at 40% maximal heart rate for 60 min. Psychological state and blood biochemical parameters were examined after exercise.

Results

In the mouse experiment, post-exercise plasma non-esterified fatty acids were significantly lower in the exercise supplemented with glutathione group (820 ± 44 mEq/L) compared with the exercise control group (1152 ± 61 mEq/L). Intermuscular pH decreased with exercise (7.17 ± 0.01); however, this reduction was prevented by glutathione supplementation (7.23 ± 0.02). The peroxisome proliferator-activated receptor-γ coactivator-1α protein and mitochondrial DNA levels were significantly higher in the sedentary supplemented with glutathione group compared with the sedentary control group (25% and 53% higher, respectively). In the human study, the elevation of blood lactate was suppressed by glutathione intake (placebo, 3.4 ± 1.1 mM; glutathione, 2.9 ± 0.6 mM). Fatigue-related psychological factors were significantly decreased in the glutathione trial compared with the placebo trial.

Conclusions

These results suggest that glutathione supplementation improved lipid metabolism and acidification in skeletal muscles during exercise, leading to less muscle fatigue.

Electronic supplementary material

The online version of this article (doi:10.1186/s12970-015-0067-x) contains supplementary material, which is available to authorized users.