Genotoxicity of waterpipe smoking in young adults from Sarajevo, Bosnia & Herzegovina

Background

Waterpipe, also known as a hookah or narghile, is a type of tobacco products consumption device. Recently it has been increasingly popular in Bosnia and Herzegovina and the region. Waterpipe consumers are predominantly adolescents and young adults. Many of them believe in slighter harmful effects of waterpipes, compared to cigarettes. We aimed to determine the DNA damage in oral leukocytes and buccal cells of young individuals who have smoked a waterpipe for more than one year.

Methods

The study group consisted of 40 cigarette non-smokers who regularly smoked a waterpipe on average of once per week. As a control, 40 non-smoking individuals were selected to match smokers for age. All participants in the study were healthy male and female adults from Bosnia and Herzegovina, 18-30 years of age. Before sampling, detailed survey and informed consent have been provided by each participant. Comet assay in oral leukocytes and buccal micronucleus cytome (BMCyt) assay in exfoliated buccal cells were applied.

Results

Almost half of waterpipe smokers (WPS) tasted waterpipe at 15-16 years of age. Comet assay analysis showed increased tail intensity, tail length, and tail moment values among WPS compared to non-smokers (NS) (p = 0.0001, p = 0.0067, and p = 0.0001, respectively). Frequencies of the micronucleated (p = 0.0004), binucleated (p = 0.01), karyorrhectic, (p = 0.0036), and pycnotic cells (p = 0.03) were significantly higher in WPS compared to NS group.

Conclusions

Genotoxicity and DNA damage biomarkers were increased in oral leukocytes and exfoliated buccal cells of young waterpipe smokers from Bosnia and Herzegovina, compared to NS group.

A pilot biomonitoring study of air pollution in the urban area of Sarajevo, Bosnia and Herzegovina: genotoxicity assessment in buccal cells

Air pollution, recognized as a human carcinogen, is a significant cause of death in industrial and developing countries, and Bosnia and Herzegovina (B&H) is one of the leading countries for air pollution-caused death rate and has the poorest urban air quality in Europe. Despite a population decrease, urban air pollution in B&H has increased due to traffic pollution and still intensive use of solid fuel for heating and cooking. Human biomonitoring studies, regarding the described air pollution, have not been conducted before, and particularly have not been conducted in the region of Sarajevo. Good health, well-being, and environmental protection are part of the 17 defined Sustainable Development Global Goals. Accordingly, this study aimed to determine baseline levels of DNA damage in a group of Sarajevo citizens and to compare seasonal variations in DNA damage in relation to the reported levels of air pollution. From 33 individuals included in the study, samples were collected in the summer and winter seasons. The buccal micronucleus cytome (BMCyt) assay and comet assay in leucocytes isolated from saliva were performed. Mean values and standard deviations of log-transformed tail intensity (%), tail length (µm), and tail moment results in winter were 1.14 ± 0.23, 2.20 ± 0.14, and 1.03 ± 0.29, respectively, while in the summer season those values were 1.19 ± 0.19, 2.25 ± 0.17, and 1.07 ± 0.25, respectively. No significant differences were found for the comet assay parameters. Nevertheless, BMCyt results showed significant increases in micronuclei (P = .008), binuclear cells (P = .04), karyolysis (P = .0003), condensed chromatin (P = .03), and pyknosis (P = .002) in winter. Although the results of comet and BMCyt assays are not in accordance, this study contributes to the human air pollution biomonitoring in Sarajevo, B&H, and based on the genotoxic effects of air pollution evidenced by the BMCyt biomarker further studies of this kind are necessary.

Air pollution in Sarajevo, Bosnia and Herzegovina, assessed by plant comet assay

Bosnia and Herzegovina (B&H) is among the European countries with the highest rate of air pollution-related death cases and the poorest air quality. The main causes are solid fuel consumption, traffic, and the poorly developed or implemented air pollution reduction policies. In addition, the city of Sarajevo, the capital of B&H, suffers temperature inversion episodes in autumn/winter months, which sustain air pollution. Human biomonitoring studies may be confounded by the lifestyle of subjects or possible metabolic alterations. Therefore, this study aimed to evaluate Ligustrum vulgare L. as a model for air pollution monitoring by measuring DNA damage at one rural and two urban sites. DNA damage was measured as tail intensity (TI) in L. vulgare leaves, considering seasonal, sampling period, leaf position and staging, and spatial (urban versus rural) variation. Effects of COVID-19 lockdown on TI were assessed by periodical monitoring at one of the selected sites, while in-house grown L. vulgare plants were used to test differences between outdoor and indoor air pollution effects for the same sampling period. Significantly higher TI was generally observed in leaves collected in Campus in December 2020 and 2021 compared with March (P < 0.0001). Outer and adult leaves showed higher TI values, except for the rural site where no differences for these categories were found. Leaves collected in the proximity of the intensive traffic showed significantly higher TI values (P < 0.001), regardless of the sampling period and the stage of growth. In regards to the COVID-19 lockdown, higher TI (P < 0.001) was registered in December 2020, after the lockdown period, than in periods before COVID-19 outbreak or immediately after the lockdown in 2020. This also reflects mild air pollution conditions in summer. TI values for the in-house grown leaves were significantly lower compared to those in situ. Results showed that L. vulgare may present a consistent model for the air pollution biomonitoring but further studies are needed to establish the best association between L. vulgare physiology, air quality data, and air pollution effects.

Novel boron-containing compound, halogenated boroxine, induces selective cytotoxicity through apoptosis triggering in UT-7 leukemia

Apoptosis induction is a promising approach in targeting tumor cells. As halogenated boroxine (HB) shows antitumor activity, but its mechanism of action in hematological tumors remains unclear, in this study, we aimed to analyze apoptosis triggering in normal and UT-7 leukemia cells by HB. Methods for assessing cell viability and cytotoxicity, apoptosis detection, relative expression of 84 apoptosis-associated genes and BCL-2, and functional analysis were applied. Pronounced HB activities in inhibition of cell viability, cytotoxicity, and apoptosis induction with measurable differences between tumor and normal cells were found. HB modulated the expression of 21 genes, predominantly downregulated the antiapoptotic genes in leukemia. The functional association revealed HB's impact on inhibition of NF-κB signaling pathway. BCL-2 expression decreasing was found only in UT-7 leukemia. This study identified HB as an apoptosis inducer affecting leukemia but not normal cells considering mechanisms of selective activity that may be a great advantage of HB applications.

Comparative analysis of two L-carnitine preparations and their concentration effects on CAT expression in healthy human peripheral blood lymphocyte cultures

CAT gene encodes catalase, a key antioxidant enzyme in the body against oxidative stress. This enzyme plays an important role in the molecular mechanisms of inflammation, apoptosis, mutagenesis and tumorigenesis. Anti-oxidant L-carnitine is used in food supplementation, medical co-treatment and bodyweight regulation. We aimed to investigate molecular basis of L-carnitine commercial preparations supplementation in reducing oxidative stress with customized CAT gene assay in vitro. Human lymphocytes cell culture was established using standard procedure and treated with range of concentrations of L-carnitine in two preparations. We tested two preparations: 500 mg tablets of L-carnitine and liquid L-carnitine with vitamin B6. L-carnitine significantly reduced the expression of CAT gene in cultured lymphocytes at concentrations of 50 μmol/l and 250 μmol/l compared to negative control, (p = 0,001; p = 0,001; respectively). The L-carnitine liquid supplement with vitamin B6 also reduced the transcription of CAT gene at concentrations of 50 μmol/l and 250 μmol/l as compared to the negative control (p = 0,018; p = 0,006; respectively). Selected L-carnitine preparations modulated the transcriptional activity of the antioxidant enzyme gene in human lymphocyte culture, indicating its possible effects in inhibition of pro-inflammatory processes that involve catalase activity.

Effects of curcumin and luteolin on viability and cell death induction in NFS-60 cell line

Inducing cell death in tumor cells has been recognized as a promising strategy in curing tumors. Parallely, natural products, especially those with long-known usage in folk medicine, are gaining demanding and extensive clinical interests. Aiming to contribute to overall knowledge of curcumin and luteolin antitumour potentials, we analyzed their effects on cell death induction in NFS-60 cell line, using Trypan blue exclusion assay and TransDetect® Anenexin V-EGFP/PI assay. Results show that both tested agents induce cell death, especially in higher applied concentrations, but further investigations are needed to elucidate the mechanisms behind it.

Bioflavonoids protect cells against halogenated boroxine-induced genotoxic damage by upregulation of hTERT expression

Plant bioflavonoids are widely present in the human diet and have various protective properties. In this study, we have demonstrated the capacity of delphinidin and luteolin to increase human telomerase reverse transcriptase (hTERT) expression level and act as protective agents against halogenated boroxine-induced genotoxic damage. Halogenated boroxine K2(B3O3F4OH) (HB), is a novel compound with potential for the treatment of both benign and malignant skin changes. In vivo and in vitro studies have confirmed the inhibitory effects of HB on carcinoma cell proliferation and cell cycle progression as well as enzyme inhibition. However, minor genotoxic effects of HB are registered in higher applied concentrations, but those can be suppressed by in vitro addition of delphinidin and luteolin in appropriate concentrations. Fresh peripheral blood samples were cultivated for 72 h followed by independent and concomitant treatments of HB with luteolin or delphinidin. We analyzed the differences in relative hTERT expression between series of treatments compared with controls, which were based on normalized ratios with housekeeping genes. The obtained results have shown that selected bioflavonoids induce upregulation of hTERT that may contribute to the repair of genotoxic damage in vitro.

Micronuclei frequencies in peripheral blood and buccal exfoliated cells of young smokers and non-smokers

Cytogenetic biomarkers, such as micronuclei in peripheral blood or oral mucosa, are widely used for evaluation of exposure to genotoxins or carcinogens. Tobacco is one of the strongest carcinogens, responsible for development of different types of cancers. The aim of this study was to assess the genotoxicity of cigarette consumption in young smokers and to correlate results of cytogenetic analysis in peripheral blood lymphocytes and exfoliated buccal cells. The study was conducted on samples taken from 43 smokers and 44 non-smokers, young individuals from Bosnia and Herzegovina. Significantly higher frequency of micronuclei in peripheral blood lymphocytes was observed in smokers (p < 0.05). No significant correlations were found for age, duration and intensity of smoking, and frequency of micronuclei in lymphocytes. Significantly higher frequency of degenerated (apoptotic) buccal cells was also revealed in smokers (p < 0.05). The frequency of apoptotic cells in smokers was significantly influenced by the age of participants (F = 8.649; p < 0.01) and duration of smoking (F = 5.389; p < 0.05). Results of cytogenetic analysis conducted in peripheral blood and exfoliated buccal cells are in significant positive correlation, indicating complementarities of those analyses.

Cytogenetic Evaluation of Paracetamol Effects in Human Lymphocytes Culture

Paracetamol is a common analgesic and antipyretic drug. It has been recognized as one of the most ordinary medications taken in overdoses. We examined the possible genotoxic effects of high paracetamol concentrations expected to occur after overdose. Paracetamol was added to the cultures at the beginning of the cultivation period. Separate cultures for three tested concentrations of paracetamol (50 microg/mL, 100 microg/mL, and 200 microg/mL) were set. Effects of paracetamol were evaluated by micronucleus cytokinesis-block assay, chromosome aberration analysis, and nuclear division index. Results demonstrate that paracetamol concentration of 200 microg/mL expresses certain genotoxic effects in human peripheral blood lymphocytes.

Micronuclei occurrence in population exposed to depleted uranium and control human group in correlation with sex, age and smoking habit

Observation of micronuclei presents reliable method for evaluation of genotoxicity effects on chromosomal level. One of genotoxins evidenced in the environment as impact of the last conflict in Bosnia and Herzegovina is depleted uranium. This research included an evaluation of genctic load in lymphocytes of individuals from population exposed to depleted uranium and the control group in correlation with sex, age and smoking habit. Results have shown increased micronuclei formation within exposed population and their statistically significant correlation with ages.