Assessment of concentration and toxicological (Cancer) risk of lead, cadmium and chromium in tobacco products commonly available in Bangladesh

Mitigating heavy metal accumulation in tobacco: Strategies, mechanisms, and global initiatives

The threat of heavy metal (HM) pollution looms large over plant growth and human health, with tobacco emerging as a highly vulnerable plant due to its exceptional absorption capacity. The widespread cultivation of tobacco intensifies these concerns, posing increased risks to human health as HMs become more pervasive in tobacco-growing soils globally. The absorption of these metals not only impedes tobacco growth and quality but also amplifies health hazards through smoking. Implementing proactive strategies to minimize HM absorption in tobacco is of paramount importance. Various approaches, encompassing chemical immobilization, transgenic modification, agronomic adjustments, and microbial interventions, have proven effective in curbing HM accumulation and mitigating associated adverse effects. However, a comprehensive review elucidating these control strategies and their mechanisms remains notably absent. This paper seeks to fill this void by examining the deleterious effects of HM exposure on tobacco plants and human health through tobacco consumption. Additionally, it provides a thorough exploration of the mechanisms responsible for reducing HM content in tobacco. The review consolidates and synthesizes recent domestic and international initiatives aimed at mitigating HM content in tobacco, delivering a comprehensive overview of their current status, benefits, and limitations.

Inhalation exposure to toxic heavy metals in nail salon technicians and health risk assessment using Monte Carlo simulation

OBJECTIVE

Nail salons offer a developing and diverse occupation for many women, especially the new generation. Due to the increasing apprehension surrounding heavy metals in dust caused by filing nails containing dried nail polish, the present study was designed aimed to health risk assessment of heavy metals in breathing zone of nail salon technicians (NSTs).

METHODS

This is a cross-sectional study that was conducted in NSTs. The concentration of Cadmium (Cd), Lead (Pb), Nickel (Ni), Chromium (Cr) and Manganese (Mn)in breathing zone of 20 NSTs was determined using ICP-OES.

RESULTS

The metal concentrations were in the following order: Mn > Pb > Ni > Cr > Cd with corresponding arithmetic mean values of0.008, 0.0023, 0.0021, 0.001 and 0.0006 mg m-3, respectively, which are exceeded the recommended levels stated in the indoor air guidelines. The average lifetime carcinogenic risk (LCR) for Cr, Cd, Ni and Pb was calculated 0.0084, 0.00054, 0.00026 and 1.44 E - 05, respectively. The LCR values of all metals (except Pb) exceeded the acceptable level set by the USEPA. The mean of Hazard quotients (HQ) for Mn, Cd, Cr, Ni and Pb were calculated to be23.7, 4.74, 2.19, 0.51 and 0.0.24, respectively. The sensitivity analysis showed that, the exposure frequency (EF) for Cr and Ni had the strong effects on generation of both LCR and HQ. Furthermore, the concentrations of Mn, Cd and Pb had strong impacts on the HQ generation and the concentration of Cd and Pb had main effects on LCR generation.

CONCLUSION

To effectively reduce pollutant concentration, it is recommended to install a ventilation system near nail salon work tables and conduct continuous monitoring and quality control of nail products.

Assessment of Essential and Potentially Toxic Elements in Water and Sediment and the Tissues of Sciaena deliciosa (Tschudi, 1846) from the Coast of Callao Bay, Peru

The lorna drum Sciaena deliciosa is a coastal demersal species and one of the underlying artisanal fisheries in some areas of Peru, and is also a source of protein for Peruvian coastal dwellers. The investigation addresses concern about the environmental impact on this fish species and the potential risks to human health through the consumption of contaminated seafood. This research endeavors to assess the concentration of potentially toxic and essential elements in the muscle and liver tissues of S. deliciosa, in addition to the presence thereof in water and sediment capture areas on the coast of Callao, Peru. The study revealed that, in water samples, Ag, Ni, and Zn exceed Peruvian standards, but were below international standards, and Ba, P, Se, and Sn exceed international standards. In the sediments, As, Cd, Pb, Fe, and Zn were above international standards. In the fish, S. delicious muscle demonstrated As, Hg, and Pb exceeding at least one international standard. In the liver, As, Hg, Pb, and Cu exceed international standards. The study approach increased accuracy in risk assessments, offering crucial insights into the interplay between heavy metal pollution, water quality, and animal health, informing risk management strategies. Future studies can explore the long-term effects of heavy metal exposure on different organisms and consider their cumulative impact on health.

Assessing the health risks of dermal exposure to heavy metals dust among nail salon technicians

BACKGROUND

Nail salon technicians are susceptible to potential exposure to a diverse array of hazardous chemicals in the form of dust or vapors. One of the main routes of exposure is dermal contact.

OBJECTIVE

The aim of present study was to health risk assessment of dermal exposure to heavy dust containing heavy metals in nail salon technicians.

METHODS

Dust sampling was done on the work surface of 20 available nail salon technicians. The concentration of five metals including cadmium, lead, chromium, nickel, and manganese were determined using ICP-MS. Afterwards, the United States Environmental Protection Agency (USEPA) guideline was used to estimate the potential health risks, including carcinogenic and non-carcinogenic risks, associated with the analyzed metals.

RESULTS

Results indicated the mean concentrations of Pb, Cd, Ni, Cr and Mn were 0.7953±0.4373, 0.0952±0.0264, 0.7666±0.8629, 0.4900±0.5994 and 1.134±0.4736, respectively. The hazard quotient (HQ) of all metals was within the permissible value, while hazard index (HI) was greater than 1. The probability of cancer risk (CR) resulting from dermal exposure to Ni, Cd and Cr exceeded the acceptable risk levels (10 - 6-10-4), but CR calculated for Pb was less than allowable value.

CONCLUSION

Implementation of engineering controls such as downdraft vented nail tables and portable source capture systems is necessary. Besides, the use of personal protective equipment such as disposable nitrile gloves, N95 respirator masks, and ensuring proper training on safe work practices is recommended.

A method for cancer elemental risk assessments in hookah: An example in two common types of traditional and flavored tobaccos in Iran

AIM

This study aimed to compare the elemental composition of traditional and flavored hookah tobacco, with a focus on heavy metals.

METHODS

We used inductively coupled plasma mass spectrometry (ICP-MS) to analyze the concentrations of 29 elements in the raw tobacco, tobacco ash, hookah water after smoking, and tobacco smoke.

RESULTS

The results showed that the traditional tobacco had significantly higher metal concentrations than the flavored tobacco in all samples. Most of the toxic metals (more than 98 %) remained in the smoke of both types of tobacco. The tobacco and hookah smoke contained high levels of harmful metals that can pose health risks to hookah users.•ICP-MS provides a comprehensive analysis of multiple elements simultaneously and it allows for precise quantification of metal concentrations in different samples.•ICP-MS requires specialized equipment and trained personnel and it may not detect elements present in extremely low concentrations.

Heavy metals in popularly sold branded cigarettes in Bangladesh and associated health hazards from inhalation exposure

Tobacco products are widely recognized as a major contributor to death. Cigarette smoke contains several toxic chemicals including heavy metals particulate causing high health risks. However, limited information has been available on the health risks associated with the heavy metals in cigarettes commonly sold in the Bangladeshi market. This study evaluated the concentrations and potential health risks posed by ten concerned heavy metals in ten widely consumed cigarette brands in Bangladesh using an atomic absorption spectrometer. The concentration (mg/kg) ranges of heavy metals Pb, Cd, Cr, As, Co, Ni, Mn, Fe, Cu, and Zn vary between 0.46-1.05, 0.55-1.03, 0.80-1.2, 0.22-0.40, 0.46-0.78, 2.59-3.03, 436.8-762.7, 115.8-184.4, 146.6-217.7, and 34.0-42.7, respectively. We assume that the heavy metals content among cigarette brands is varied due to the differences in the source of tobacco they use for cigarette preparation. The carcinogenic risks posed by heavy metals follow the order of Cr > Co > Cd > As > Ni > Pb, while the non-carcinogenic risks for Cu, Zn, Fe, and Mn were greater than unity (HQ > 1), except for Fe. The existence of toxic heavy metals in cigarette tobacco may thus introduce noticeable non-carcinogenic and carcinogenic health impacts accompanying inhalation exposure. This study provides the first comprehensive report so far on heavy metal concentration and associated health risks in branded cigarettes commonly sold in Bangladesh. Hence, this data and the information provided can serve as a baseline as well as a reference for future research and have potential implications for policy and legislation in Bangladesh.

Pollution and health risk assessment of mine tailings contaminated soils in India from toxic elements with statistical approaches

The rapid mining activities of mica mines in Giridih district, India, have led to toxic metal pollution of agricultural soil. This is a key concern for environmental risk and human health. 63 top soil samples were collected at a distance of 10 m (Zone 1), 50 m (Zone 2), and 100 m (Zone 3) from near 21 mica mines with agriculture fields. The mean concentration of total and bio-available toxic elements (TEs - Cr, Ni, Pb, Cu, Zn, and Cd) was higher in zone 1 across three zones. The Positive matrix factorization model (PMF) and Pearson Correlation analysis were used to identify waste mica soils with TEs. Based on PMF results, Ni, Cr, Cd, and Pb were the most promising pollutants and carried higher environmental risks than the other TEs. Using the self-organizing map (SOM), zone 1 was identified as a high-potential source of TEs. Soil quality indexes for TEs risk zone 1 were found to be higher across three zones. Based on the health risk index (HI), children are more adversely affected than adults. Monte Carlo simulations (MCS) model and sensitivity analysis of total carcinogenic risk (TCR), children were more affected by Cr and Ni than adults through ingestion exposure pathways. Finally, a geostatistical tool was developed to predict the spatial distribution patterns of TEs contributed by mica mines. In a probabilistic assessment of all populations, non-carcinogenic risks appeared to be negligible. The fact that there is a TCR can't be ignored, and children are more likely to develop it than adults. Mica mines with TEs contamination were found to be the most significant anthropogenic contributor to health risks based on source-oriented risk assessment.

Comparison of urine trace element levels in tramadol addiction alone and its co-abuse with cigarette and opium in Western Iran

Tramadol is an opioid pain medication used to treat moderate to severe pain. Tramadol consumers tend to co-abuse some other substances such as opium, cigarettes, alcohol, and cannabis and each of these substances may impair trace elements homeostasis in the body. Therefore, this case-control study aimed to compare the urinary concentration of some essential and toxic elements in tramadol addiction alone and its co-abuse with cigarette and opium in Western Iran. For this purpose, urine samples were collected in two groups of tramadol (n = 72) and control subjects (n = 62) from March to November 2020. The case group was divided into three groups: tramadol alone, tramadol + opium, and tramadol + cigarettes. Moreover, ICP-MS (Agilent 7900) was used to measure trace element concentrations in the urine samples. Based on our results, Fe was the only element markedly higher among controls as compared to tramadol users (p < 0.001). Moreover, the concentration levels of As appeared to be the same among both groups, but the levels of other elements including Ca, Cd, Cr, Mn, Cu, Zn, Co, Ni, Se, and Pb were all significantly higher among tramadol users as compared to control group. The rank-based regression analysis illustrated that no contribution of sex and age effect was found by the regression model on the levels of all 12 studied elements. While, smoking was found to affect the levels of Fe (β = 0.163, P = 0.025) and Co (β = 0.411, p < 0.001) so that smoking reduced Fe levels but elevated Co concentration levels. Abuse of tramadol along with cigarettes and opium increased the concentration of some heavy metals in urine samples compared to the control group. However, these results showed no significant effect of age, sex, smoking habit, and amount of tramadol usage on the levels of trace elements.

Examining of Heavy Metal Concentrations in Hookah Smokers

Hookah smoking has been spreading around the world, especially among young adults. The current study aimed to investigate the concentration of heavy metals and elements and clinical symptoms in hookah users in comparison with non-users. To the best of our knowledge, the present study represents the first scientific contribution indicating levels of several heavy metals and elements in urine and blood in hookah users and non-users as well as evaluating clinical symptoms. This research was implemented in Iran among 100 males divided into two groups (50/group): control and hookah users. Heavy metal contamination (lead, cadmium, arsenic, thallium, zinc, and copper) in blood and urine samples was assayed by graphite furnace atomic absorption spectrometry (GFAAS). Duration of hookah use was 7.06 ± 4.57 years. The mean ± SD of lead, arsenic, and thallium concentrations was 3.77 ± 2.22, 8.50 ± 4.34, and 4.22 ± 2.69 μg/L. The mean levels of blood for lead, arsenic, and urinary thallium in hookah users are significantly higher than the control group (p < 0.05). The most frequent clinical symptoms in hookah smokers were constipation and fatigue. Findings from this study might guide the development of policies to regulate hookah smoking and prevent adverse health effects associated with hookah smoking.

Effects of tobacco smoke on indoor air quality: the use of mosses in biomonitoring

This research was carried out to assess the possibility of using Pleurozium schreberi mosses as bioindicators of atmospheric aerosol pollution in living quarters (kitchen and bedroom), with metals originating from tobacco smoke from various types of cigarettes: conventional cigarettes, e-cigarettes and heated tobacco products. The moss-bag method of active biomonitoring was used. The mosses were exposed in these indoor spaces for three months and, after the exposition period, their analytes - Ni, Cu, Zn, Cd and Pb - were determined using flame atomic absorption spectrometry (F-AAS). Results were interpreted using the relative accumulation factors (RAF), coefficients of variation (CV) and the Wilcoxon test. As a result of the research, it was found that there were statistically significant differences in Zn and Cd concentrations in tobacco smoke from different types of cigarettes. The analyses showed that heated tobacco products contaminate indoor air with metals, similar to conventional cigarettes and e-cigarettes. It was demonstrated that the reliability of biomonitoring results was affected, for example, by the method of preparation of bioindicator samples, such as mosses.

Analyzing pesticides and metal(loid)s in imported tobacco to Saudi Arabia and risk assessment of inhalation exposure to certain metals

Exposure to toxic chemicals through smoked tobacco is a significant global public health issue due to their genotoxic and carcinogenic properties. The study aims to (1) measure Arsenic (As), Cadmium (Cd), Cobalt (Co), Chromium (Cr), Mercury (Hg), Nickle (Ni), lead (Pb), and 407 pesticides in tobacco commercialized in Saudi Arabia; and (2) evaluate human health risks associated with smoking tobacco. Thus, we analyzed 60 tobacco samples per brand from eight of the most popular tobacco brands in the Saudi market. The analyzed tobacco contained significant concentrations of toxic metal (loid)s and banned pesticides. Twenty-three out of 407 pesticide residues were found, with an average concentration of 0.004-1.155 µg/g. Average concentrations of As, Cd, Co, Cr, Hg, Ni, and Pb for all brands were 0.16, 0.57, 0.75, 1.36, 1.94, 0.01, and 0.37 µg/g, respectively. The risk assessment indicated that high cancer risks are associated with exposure to As, Cd, Cr, and Ni, while lower risks are associated with Pb. Additionally, the potential cancer risk estimated for Cr was higher than other toxic elements. The cumulative cancer risks (95%) under three different cases for all brands were greater than the permissible limits (=10-4). The chances of getting cancer through inhalation of particulate As, Cd, Cr, Ni, and Pb was 4 in 10 000 cases in the best case scenario (1 cigarette per day). Therefore, metal content in cigarette tobacco should be reduced to improve public health.HIGHLIGHTSAll tested brands contained banned pesticide residues except for brand C.Tobacco samples contained significant concentrations of toxic metal(loid)s.A high risk of developing cancer is associated with exposure to As, Cd, Cr, and Ni, while a lower risk is associated with exposure to Pb.

Chemical characteristics and cancer risk assessment of smokeless tobacco used in Tunisia (neffa)

Introduction

neffa, a form of air-dried smokeless tobacco used in North Africa, is spuriously perceived as a lower risk alternative to smoking. The objective of this study was to provide information on some harmful constituents of neffa and to use them for cancer risk assessment.

Methods

a high-performance liquid chromatography method coupled with fluorescence detector was used to determine polycyclic aromatic hydrocarbons (PAHs) in one sample of neffa. An atomic absorption spectrometry was performed to determine the concentrations of lead and cadmium in three samples of neffa. The levels of toxicants found in neffa were used to assess for lifetime cancer risk as advocated by the US Environment Protection Agency.

Results

the determination of PAHs in neffa allowed the identification of phenanthrene and anthracene. However, the higher molecular weight PAHs such as Benzo(a)Pyrene B(a)P were not detected. The concentrations of cadmium and lead varied between 1.3 to 2.8µg/g and 1.7 to 4.6µg/g respectively. Cancer risk for cadmium and lead varied between 4.2E-03 to 9.3E-03 and 2.5E-06 to 6.4E-06 respectively. Cancer risk for Cd exceeded the range of 10E-04 to 10E-06 of an acceptable risk.

Conclusion

neffa is not a healthy alternative for overcoming smoking addiction. It contains mineral and organic pulmonary toxicants. This study could serve as a scientific basis to inform consumers about the products´ toxicity and help them to quit smokeless tobacco (SLT) use.

Assessing Heavy Metal Burden Among Cigarette Smokers and Non-smoking Individuals in Iran: Cluster Analysis and Principal Component Analysis

Smoking is one of the major causes of mortality and numerous diseases, both directly and indirectly. The role of smoking as a significant risk factor is already known in several human diseases such as cardiovascular diseases, lung cancer, and chronic obstructive pulmonary disease. We aimed to compare the toxicity of heavy metal levels in the two groups of cigarette smokers and non-smokers in Birjand during 2018. In this case-control study, 70 smokers were enrolled as the case group and 70 individuals with no history of smoking as control group. The cases were selected from among those who smoked 10 cigarettes per day without a drug use history. Heavy metal concentrations were collected in participants' serum samples. Cluster analysis and principal components analysis were employed to compare heavy metal toxicity between the groups. The duration of smoking and the number of cigarettes consumed per day were 14.36 ± 12.75 years and 11.32 ± 7.23, respectively. The concentration of thallium (Ti), arsenic (As), manganese (Mn), and copper (Cu) was significantly higher in the smoker group than that in the non-smoker group (p < 0.05). Lead (Pb), cadmium (Cd), and cobalt (Co) are among the most important metals accumulated in smokers' blood, and 21.6% of our study's total data was associated with them. Cluster analysis in the smoker group, including A1 (Cd), A2 (Co, Pb), B1 (Ti), B2 (mercury (Hg), As, chromium (Cr), iron (Fe), nickel (Ni), and zinc (Zn)) and C (Mn and Cu). In our study, cluster analysis showed a different grouping of elements in patient and control groups. Lead, cadmium, and cobalt were the most critical metals accumulated in the blood of cigarette smokers.

Toxicological approaches for the quantitative inhalation risk assessment of toxic metals from tobacco smoke: application on the deterministic and probabilistic inhalation risk assessment of cadmium for Austrian smokers

OBJECTIVE

The objective of this study was the assessment of risks from inhalation exposure of Austrian smokers to cadmium through established toxicological approaches with emphasis on the exposure assessment component, which is challenging regarding the actual amount of metal that is inhaled and the simulation of the smoking pattern.

MATERIALS AND METHODS

Exposure assessment comprised an estimation of the proportion of cadmium inhaled through smoking and actual occurrence data in tobacco products and survey smoking habits, which were integrated in alternative scenarios through a deterministic and a probabilistic Monte Carlo simulation method. Risks were characterized through the comparison of the exposure with health-based guidance values, as well as through the assessment of the excess lifetime cancer risk (ELCR), the non-cancer hazard quotient (NCHQ), and the margin of exposure (MOE). The strengths, the uncertainties, and the limitations of the different methodologies were discussed.

RESULTS AND DISCUSSION

Upper exposures are close or exceed the Permitted Daily Exposure. Respiratory ELCRs are unacceptable compared to the benchmark range of 1.0E-06 to 1.0E-04. Renal and respiratory NCHQs exceed the target value of 1.0 by 3- to 17-fold. MOEs are not protective enough for cancer and non-cancer effects. The amount of cadmium that reaches the lung is a key source of uncertainty.

CONCLUSION

Probabilistic estimates provide a refined capture of the actual inhalation exposure. Risk estimates and gender and age profiles are alarming, especially for young smokers. Application of toxicological approaches, combined with realistic assessment of the inhalation exposure levels, can support risk communication and management.

Ecological and Health Risks Assessment of Potentially Toxic Metals and Metalloids Contaminants: A Case Study of Agricultural Soils in Qatar

In recent years, Qatar has witnessed exponential growth in the human population, urbanization, and increased anthropogenic activities, including agriculture. Potentially toxic environmental contaminants, including metals and metalloids, are commonly found in emerging economies. At high concentrations, elements such as As, Cr, and Ni can be hazardous and may lead to various health problems in humans, including cancer. The current study measured As, Cd, Cr, Cu, Ni, Pb, V, and Zn concentrations in agricultural soils. Pollution levels and potential negative impacts on human and environmental health were determined using the United States Environmental Protection Agency (USEPA) standard methodologies. According to the study’s findings, the studied element concentrations descended in the following order: Zn > Cr > V > Ni > As > Cu > Pb > Cd. Of these, As (27.6 mg/kg), Cr (85.7 mg/kg), Ni (61.9 mg/kg), and Zn (92.3 mg/kg) concentrations were higher than average world background levels. Each of these elements also had an enrichment factor (EF > 1), indicating their anthropogenic origin. The combined pollution load index (PLI > 1) and geo-accumulation index (Igeo) range values of −0.2–2.5 further indicated that the soil was up to 58% polluted. However, the ecological risk factor (Er ≤ 40.6) and potential ecological risk index (PERI = 79.6) suggested low ecological risk. A human health risk evaluation showed that only As, with a hazard index (HI) of 1.3, posed a noncarcinogenic risk to infants. Additionally, As, Cr, and Ni, with total carcinogenic risk (TCR) values of 1.18 × 10⁻⁴ and 2.06 × 10⁻⁴ for adults and children, respectively, proved carcinogenic to both age groups. The elements’ carcinogenic risk (CR) potential descended in the following order: Ni > As > Cr. Additionally, for both adults and children, oral ingestion is the most likely exposure pathway. Our findings support the need for closer monitoring of potentially toxic metals and metalloids levels in cultivated soils and farm produce in Qatar. Reducing the elements’ bioavailability in soil and developing innovative remediation technologies is needed to limit potential risks to human health. Further studies on As, Cr, and Ni gastrointestinal bioaccessibilities are needed to fully understand the effects after long-term exposure and the cancer-causing potential of these elements over a lifetime.

Assessment of heavy metal pollution in the agricultural soils, plants, and in the atmospheric particulate matter of a suburban industrial region in Dhaka, Bangladesh

Unplanned industrialization and improper management of wastes and gases into open surfaces are affecting the agricultural lands causing heavy metal pollution. This study monitored a suburban industrial zone located beside the Dhaka Export Processing Zone (DEPZ) at the Dhaka district in Bangladesh. We studied the heavy metal (Fe, Mn, Cr, Cu, Ni, Co, Zn, Pb, and Cd) concentration in the agricultural soils, plants, and in the atmospheric particulate matter (PM). The soils were found moderately contaminated with Fe, Cu, Ni, Co, and Zn and less contamination with Mn, Cr, Pb, and Cd. The enrichment factor (EF) and pollution load index (PLI) concluded a moderate level of soil pollution in this region. Besides, the plant samples showed an excess level of Cr and a similar level of Cu, Ni, Co, Zn, Pb, and Cd compared with the levels of industrial polluted sites of Bangladesh. The atmospheric PM analysis showed the presence of Fe, Mn, Cu, Ni, Zn, and Pb metals. The EF showed the anthropogenic origin of Mn and Ni in the atmospheric PM. The statistical correlation (r < 0.0001) of soil and plant heavy metals showed the possibility of transfer of metals from soil to plant which will cause the increase of pollution intensity. Overall, this agricultural region became an intermediate pollution zone. This study will help the decision-maker become conscious of heavy metal pollution in the suburban regions to monitor agricultural lands from anthropogenic pollution.

Immune response in glioma's microenvironment

Objectives

Glioma is the most common tumor of the central nervous system. In this review, we outline the immunobiological factors that interact with glioma cells and tumor microenvironment (TME), providing more potential targets for clinical inhibition of glioma development and more directions for glioma treatment.

Content

Recent studies have shown that glioma cells secrete a variety of immune regulatory factors and interact with immune cells such as microglial cells, peripheral macrophages, myeloid-derived suppressor cells (MDSCs), and T lymphocytes in the TME. In particular, microglia plays a key role in promoting glioma growth. Infiltrating immune cells induce local production of cytokines, chemokines and growth factors. Further leads to immune escape of malignant gliomas.

Summary and Outlook

The complex interaction of tumor cells with the TME has largely contributed to tumor heterogeneity and poor prognosis. We review the immunobiological factors, immune cells and current immunotherapy of gliomas, provide experimental evidence for future research and treatment of gliomas.

N, K. S, C. VK, K. ND, C. SK, Maddu N. Smokeless tobacco induced biophysical and biochemical alterations in the plasma, erythrocytes, and platelets of panmasala users: Subsequent biological effects

AIM & BACKGROUND

Smokeless tobacco (SLT) products are extensively consumed throughout the world including India. These products act as the primary addictive agents, due to the presence of nicotine among other tobacco products to humans and animals and its quitting is difficult. Higher the exposure of SLT products more is the toxic effects and alterations in erythrocytes and platelets.

OBJECTIVES

The products of smokeless tobacco could cause increase in the concentrations of oxidants (free radicals), decrease the activities antioxidant enzymes, activate the process of programmed cell death through enhanced expression of inducible nitric oxide synthase. Smokeless tobacco products represent a major modifiable risk factor for the development of redox imbalance through the enhanced production of reactive oxygen species and diminished activities of antioxidant enzymes in plasma, bio-membranes of erythrocytes, and platelets and induction of apoptosis in the blood.

MATERIALS AND METHODS

The protein expression of inducible nitric oxide synthase (iNOS) was studied by western blot and gene expression of apoptotic proteins, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) was evaluated by RT-PCR technique. Membrane fluidity of erythrocytes and platelets was studied by the fluorescence method.

RESULTS

The results of the present study revealed that significantly elevated levels of iNOS enzyme in plasma, erythrocyte, and platelet membranes of panmasala users. We found that gene expression levels of Bcl2, Bax, IL-6, caspase proteins (Caspase 8, Caspase 10, and Caspase 12) are greater and decreased levels of TNF-α with no significant change in blood of smokeless tobacco users in comparison with normal controls. In addition, there were substantial significantly higher in concentrations of nicotine, cotinine, and epinephrine in the plasma of panmasala users than non-tobacco users. Panmasala can be caused a significant increase in nitroxidative stress marker (LPO, NO, and ONOO-) values and significant decrease in the levels of antioxidant enzymes in erythrocytes and platelets.

CONCLUSION

On the basis of the present study results, it may be concluded that the chronic use of panmasala than any smokeless tobacco products may be a contributory risk factor or may give conclusive idea and has been associated with the expansion of the development of structural and functional alterations in the erythrocyte and platelet membranes induced oxidative damage and apoptosis, possibly further enhanced by nicotine and tobacco-specific N-nitrosamines. SLT exposure had implicated a threat and enormous implications on public health and is required to prove that may not be viewed as a safe alternative to any tobacco products.

Lead (Pb) exposure induces dopaminergic neurotoxicity in Caenorhabditis elegans: Involvement of the dopamine transporter

Lead (Pb) is an environmental neurotoxicant, and has been implicated in several neurological disorders of dopaminergic dysfunction; however, the molecular mechanism of its toxicity has yet to be fully understood. This study investigated the effect of Pb exposure on dopaminergic neurodegeneration and function, as well as expression level of several dopaminergic signaling genes in wild type (N2) and protein kinase C (pkc) mutant Caenorhabditis elegans. Both N2 and pkc mutant worms were exposed to Pb²⁺ for 1 h. Thereafter, dopaminergic (DAergic) neurodegeneration, behavior and gene expression levels were assessed. The results revealed that Pb²⁺ treatment affects dopaminergic cell morphology and structure in worms expressing green fluorescent protein (GFP) under a DAergic cell specific promoter. Also, there was a significant impairment in dopaminergic neuronal function as tested by basal slowing response (BSR) in wild-type, N2 worms, but no effect was observed in pkc mutant worms. Furthermore, Pb²⁺ exposure increased dat-1 gene expression level when compared with N2 worms, but no alteration was observed in the pkc mutant strains. LC–MS analysis revealed a significant decrease in dopamine content in worms treated with Pb²⁺ when compared with controls. In summary, our results revealed that Pb²⁺ exposure induced dopaminergic dysfunction in C. elegans by altering dat-1 gene levels, but pkc mutants showed significant resistance to Pb²⁺ toxicity. We conclude that PKC activation is directly involved in the neurotoxicity of Pb.