Association between the use of muscle-building supplements and DNA damage in resistance training practitioners

OBJECTIVES

Little is known about the relationship between the supplements used for sport and safety, especially regarding the induction of genotoxicity. Therefore, more knowledge about a DNA damage possibly caused using sport supplements is necessary. The aim of this study was to investigate the potential association between the use of muscle-building supplements and DNA damage in resistance training practitioners.

METHODS

Muscle-building supplements were classified into three categories based on evidence of efficacy and safety: Strong Evidence to Support Efficacy and Apparently Safe (SESEAS); Limited or Mixed Evidence to Support Efficacy (LMESE), and Little to No Evidence to Support Efficacy and/or Safety (LNESES). DNA damage was evaluated by the comet assay (DNA damage index and frequency) and buccal micronucleus by the cytome assay (micronuclei and nuclear buds). In the sequence, the adjusted analysis of covariance was performed. This study included 307 individuals ages 37.99 ± 13.95 y (52.1% men), of which 157 consumed supplements.

RESULTS

The results of the comet assay revealed that participants who used supplements had higher DNA damage indexes (P = 0.018) and damage frequency (P = 0.045) than those who reported using no supplements. Moreover, the comet assay also indicated that the participants who used supplements classified into the SESEAS category presented the highest DNA damage index (P = 0.025) and frequency (P = 0.044) compared with those who used no supplements. However, we found no significant difference in the micronuclei and nuclear buds in the evaluated groups (P > 0.05).

CONCLUSION

Supplement use is not associated with permanent damage, suggesting that SESEAS supplements are safe for consumption.

Re-evaluation of CBMN test reference values of persons continuously occupationally exposed to low doses of ionizing radiation in Serbia

When established, cytokinesis-block micronucleus (CBMN) test reference values should be periodically evaluated according to the recommendations of reference documents. The biodosimetry cytogenetic laboratory of the Serbian Institute of Occupational Health established the CBMN test reference range for people occupationally exposed to ionizing radiation in 2016. Since then, new occupationally exposed persons have been subjected to micronucleus testing, resulting in the need for re-evaluation of existing CBMN test values. The examined population comprised 608 occupationally exposed subjects - 201 from the previous laboratory database and 407 newly examined. Comparison of groups based on gender, age and cigarette consumption did not show significant differences, although certain CBMN values differed significantly between the old and new groups. Duration of occupational exposure, gender, age and smoking habit influenced micronuclei frequency in all three analyzed groups, while no relation was found between type of work and micronucleus test parameters. Since the mean values of all tested parameters in the new group of examinees are within previously established reference ranges, existing values can be used in further research.

Genomic instability in people living with HIV

The increased life expectancy of people living with HIV (PLWH) receiving antiretroviral treatment (ART) has transformed HIV infection into a chronic disease. However, patients may be at risk of accelerated aging and the accumulation of cellular damage, which may trigger the development of cancer. We evaluated genomic instability in HIV-positive individuals with different viral loads receiving antiretroviral treatment (ART) and in HIV ART-naïve individuals. We included 67 participants divided into four groups: group 1 (n = 24) HIV patients receiving reverse-transcriptase inhibitors (tenofovir/ emtricitabine/ efavirenz and abacavir/ lamivudine/ efavirenz), group 2 (n = 22) HIV patients receiving protease inhibitors combined with other antiretroviral drugs (tenofovir/ emtricitabine with ritonavir/ atazanavir or lopinavir/ ritonavir, and darunavir/ ritonavir/ raltegravir), group 3 (n = 13) HIV ART-naïve patients, and group 4 (n = 8) healthy individuals (controls). Nuclear abnormalities in buccal mucosal samples (micronuclei, binucleated cells, nuclear buds, karyorrhexis, karyolysis, and pyknosis) were quantified. Simultaneously, blood samples were taken to quantify CD4+, CD8+, and HIV viral load. There was a significant age difference between HIV ART-naïve patients and receiving ART groups. Infection time was longer in HIV patients with ART than in ART-naïve patients. There were no differences in sex, smoking, alcohol consumption, or number of micronucleated cells between the study groups. We found higher frequencies of binucleated cells and nuclear buds in HIV patients, HIV ART-naïve, and HIV ART patients compared to the control group. We found a positive correlation between nuclear buds and CD4/CD8 ratio in the HIV ART-naïve group. In conclusion, PLWH showed increased genomic instability. The CD4/CD8 ratio affects the numbers of nuclear buds and binucleated cells. These findings are pertinent to mechanisms of damage and possible strategies to mitigate carcinogenesis in PLWH.

Cytogenetic biomonitoring of road tunnel construction workers: buccal micronucleus cytome assay

Results

Road tunnel construction workers revealed higher frequencies of cells with genotoxic damage (i.e., MN and NBUD). MN and NBUD resulted to be Poisson distributed and counts of these genotoxicity biomarkers were then analysed by Poisson regression. The frequency ratio (FR) for MN was 1.31 (95% CI: 0.84-2.04), with an increase in the exposed subjects; this finding, though indicating a higher genotoxic risk in the exposed subjects, did not reach statistical significance. On the other hand, the FR for NBUD was 3.49 (95% CI: 1.86-6.56), with a statistically significant increased risk of chromosomal damage. Even the frequencies of binucleated cells (a marker of cell proliferation) and pyknotic cells (a cell death biomarker) were significantly higher in tunnel workers.

Introduction

Tunnel construction workers are exposed to complex mixtures of toxic agents, some of which are known to be genotoxic. The aim of this study was to evaluate the genotoxic risk in this occupational setting by comparing tunnel workers with a control group for frequencies of nuclear aberrations in oral exfoliated cells.

Methods

To evaluate the genotoxic effects of tunnel air pollutants, we conducted a cross-sectional, molecular epidemiological study (35 tunnel workers and 35 healthy controls) using the buccal micronucleus cytome assay. A questionnaire was administered to obtain information about demographic variables, lifestyle, dietary habits, anthropometric data, and occupational history. Buccal mucosa cells were collected by scraping the buccal mucosa with a small-headed toothbrush. Coded slides were examined blind by trained scorers for micronuclei (MN), nuclear buds (NBUD), and other nuclear abnormalities.

Conclusions

Our observations provide further knowledge and understanding of the occupational hazards of tunnel workers and confirm the complexity of effects (cytotoxic and genotoxic) probably induced by fumes and dust produced in underground operations.

Morphology based scoring of chromosomal instability and its correlation with cell viability

OBJECTIVE

The aim of this study was to devise the quantitative scoring system for Chromosomal instability (CIN) based on morphological indicators like MPM, NB, NPB, CS, La and MN in cancer cell line and to correlate it with cell viability and death.

METHODS

Human hepatocellular carcinoma (HepG2) cells were treated with drugs like Diethylstilbestrol 0-100μM, Griseofulvin 0-40μg/ml, Vincristine sulphate 0-25μg/ml, Mitomycin C 0-600ng/ml, Bleomycin 0-10μg/ml, Doxorubicin 0-30μg/ml for 24h. Following this, the CIN was assessed by counting the morphological indicators like Micronuclei (MN), Nuclear Buds (NB), Nucleoplasmic bridges, Laggards, Multipolar mitosis and chromatin strings/1000 cells in Giemsa stained smears by light microscopy and by determining the percentage of aneuploid cells by flow cytometry. The cell viability was assessed by MTT assay and percentage of apoptotic cells was determined by flow cytometry.

RESULTS

The MN and NB were most frequently seen indicators and main determinants of morphological CIN. However, the morphological CIN score did not show any correlation with cell viability and apoptosis. Aneuploidy however was found to correlate positively with cell viability and NB score in our study (P-value <0.05).

CONCLUSIONS

The study for the 1st time attempted to develop a scoring system for CIN based on morphological parameters. However, a no correlation was observed between the later and cell viability or apoptosis. More robust techniques to quantify CIN may perhaps be more helpful in exploring the true link between CIN and cell viability in future.

Environmental genotoxicity assessment along the transport routes of chemical munitions leading to the dumping areas in the Baltic Sea

The frequencies of micronuclei (MN), nuclear buds (NB) and nuclear buds on filament (NBf) were examined in 660 specimens of herring (Clupea harengus) collected in 2009-2014 at 65 study stations located mainly along the chemical munition transport routes in the Baltic Sea. The frequency of nuclear abnormalities was strongly increased in herring caught at four stations located close to chemical munition dumping sites, or CWAs - substances (chemical warfare agents) in sediments. Significant increase of MN, NB and NBf was observed in fish caught November 2010-2013 compared to 2009. The most significantly increased genotoxicity responses were recorded in fish caught at stations along CW (chemical weapons) transport routes, close to the Bornholm CW dumping area, in zones with CWAs in sediments and with oil-gas platforms.

Investigation of genome instability in patients with non-alcoholic steatohepatitis

AIM: To evaluate the occurrence of micronucleus (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) in the mitogen-stimulated lymphocytes of patients with non-alcoholic steatohepatitis (NASH).

METHODS: The study was performed in 25 (9 females, 16 males) patients newly diagnosed with NASH, and 25 healthy subjects of similar ages and genders were used as a control group. None of the controls was known to be receiving any drugs for medical or other reasons or using alcohol. Hepatosteatosis was further excluded by abdominal ultrasound imaging in the control group. The numbers of MN, NPBs and NBUDs scored in binucleated (BN) cells were obtained from the mitogen-stimulated lymphocytes of patients and control subjects. Statistical comparisons of the numbers of BN cells with MN, NPBs and NBUDs and ages between the patients with NASH and control subjects were performed.

RESULTS: The mean ages of the patients and the control group were 41.92 ± 13.33 and 41.80 ± 13.09 years (P > 0.05), respectively. The values of the mean body mass index (BMI), HOMA-IR, hemoglobin, creatinin, aspartate aminotransferase, alanine aminotransferase, triglyceride, high density lipoprotein, and low density lipoprotein were 31.19 ± 4.62 kg/m²vs 25.07 ± 4.14 kg/m², 6.71 ± 4.68 vs 1.40 ± 0.53, 14.73 ± 1.49 g/dL vs 14.64 ± 1.30 g/dL, 0.74 ± 0.15 mg/dL vs 0.80 ± 0.13 mg/dL, 56.08 ± 29.11 U/L vs 16.88 ± 3.33 U/L, 92.2 ± 41.43 U/L vs 15.88 ± 5.88 U/L, 219.21 ± 141.68 mg/dL vs 102.56 ± 57.98 mg/dL, 16.37 ± 9.65 mg/dL vs 48.72 ± 15.31 mg/dL, and 136.75 ± 30.14 mg/dL vs 114.63 ± 34.13 mg/dL in the patients and control groups, respectively. The total numbers and frequencies of BN cells with MN, NPBs and NBUDs, which were scored using the CBMN cytome assay on PHA-stimulated lymphocytes, were evaluated in the patients with NASH and control group. We found significantly higher numbers of MN, NPBs and NBUDs in the BN cells of patients with NASH than in those of the control subjects (21.60 ± 9.32 vs 6.88 ± 3.91; 29.28 ± 13.31 vs 7.84 ± 3.96; 15.60 ± 5.55 vs 4.20 ± 1.63, respectively, P < 0.0001).

CONCLUSION: The increased numbers of MN, NPBs and NBUDs observed in the lymphocytes obtained from patients with NASH may reflect genomic instability.