Polychronis Stivaktakis

Histopathological lesions, oxidative stress and genotoxic effects in liver and kidneys following long term exposure of rabbits to diazinon and propoxur.

PURPOSE The aim of the present study was to investigate the effects of diazinon and propoxur on liver and kidneys, following long term exposure of rabbits. METHODS Ten New Zealand white female rabbits were used. The animals were divided into 5 groups, consisting of 2 animals each. Diazinon (groups 1 and 2) and propoxur (groups 3 and 4) were administered at 2 different doses, and group 5 served as the control group. Histopathological lesions in the liver and kidneys, oxidative stress and oxidative DNA damage were evaluated. RESULTS Both pesticides induced focal inflammation and fibrosis in the liver and kidneys. The low dose of propoxur induced a significant increase in total antioxidant capacity (TAC), with no difference in reduced glutathione (GSH), while the high dose of propoxur induced an increase in GSH with no change in TAC. For diazinon-exposed animals, the opposite findings were observed. Both diazinon and propoxur induced a statistically significant oxidative DNA damage in the liver and kidneys and a subsequent increase in telomerase activity in these tissues, possibly as a counteracting mechanism. Furthermore, systemic inflammation, as depicted by the dose-dependent increase in telomerase activity in peripheral blood mononuclear cells (PBMCs), was observed in propoxur treated animals. CONCLUSIONS Histopathological lesions, oxidative stress and genotoxic effects were induced in liver and kidneys following long term exposure of rabbits to diazinon and propoxur.

Multicomponent Analysis of Replacement Liquids of Electronic Cigarettes Using Chromatographic Techniques

The electronic cigarette (e-cig) is an invention of the past few years and its popularity is rapidly growing all over the world. A rapid multicomponent analytical protocol for the analysis of the replacement liquids (e-liquids) of e-cig was developed using gas (GC) and liquid chromatography (LC)-mass spectrometry (MS). GC-MS-based methods were developed for the determination of the main humectants and polycyclic aromatic hydrocarbons (PAHs). For the determination and quantification of nicotine (NIC) and nitrosamines, appropriate LC-MS-based methods were developed. The approbated methods were applied for the analysis of 263 e-liquid samples obtained from the Greek market. The instruments response was linear; the limits of quantification ranged from 0.003 μg/mL for three PAHs to 1.187 μg/mL for glycerol. The precision was <16% for all analytes, while the mean accuracy ranged from 99.1% for NIC to 106.6% for the flavor 2,5-dimethylpyrazine. The measured concentrations of NIC were correlated with the theoretical concentrations as reported by the manufacturers. An analog relation between the concentration of the glycerol and of propylene glycol was noticed. The frequency of detection of flavors ranged from 30.4% for the methyl cyclopentenolone to 5.3% for 3.4-dimethoxybenzaldehyde. Nitrosamines and PAHs were not detected in any sample. Because a similar analytical protocol was not available from the existing literature so far, our study offers the advantage of complete analytical methods for rapid and simultaneous multicomponent identification.

Simulating real-life exposures to uncover possible risks to human health: A proposed consensus for a novel methodological approach

In real life, consumers are exposed to complex mixtures of chemicals via food, water and commercial products consumption. Since risk assessment usually focuses on individual compounds, the current regulatory approach doesn’t assess the overall risk of chemicals present in a mixture. This study will evaluate the cumulative toxicity of mixtures of different classes of pesticides and mixtures of different classes of pesticides together with food additives (FAs) and common consumer product chemicals using realistic doses after long-term exposure. Groups of Sprague Dawley (CD-SD) rats (20 males and 20 females) will be treated with mixtures of pesticides or mixtures of pesticides together with FAs and common consumer product chemicals in 0.0, 0.25 × acceptable daily intake (ADI)/tolerable daily intake (TDI), ADI/TDI and 5 × ADI/TDI doses for 104 weeks. All animals will be examined every day for signs of morbidity and mortality. Clinical chemistry hematological parameters, serum hormone levels, biomarkers of oxidative stress, cardiotoxicity, genotoxicity, urinalysis and echocardiographic tests will be assessed periodically at 6 month intervals. At 3-month intervals, ophthalmological examination, test for sensory reactivity to different types of stimuli, together with assessment of learning abilities and memory performance of the adult and ageing animals will be conducted. After 24 months, animals will be necropsied, and internal organs will be histopathologically examined. If the hypothesis of an increased risk or a new hazard not currently identified from cumulative exposure to multiple chemicals was observed, this will provide further information to public authorities and research communities supporting the need of replacing current single-compound risk assessment by a more robust cumulative risk assessment paradigm.

Long-term exposure of rabbits to imidaclorpid as quantified in blood induces genotoxic effect.

The present in-vivo study focuses on the genotoxic effect of the neonicotinoid pesticide imidacloprid (IMI) in rabbits. The purpose of the study was to establish a possible relationship between exposure to the pesticide (dose and duration) and genotoxicity. Furthermore, an analytical method for the simultaneous determination of IMI and its major metabolite 6-chloronicotinic acid (6-ClNA) in blood was developed and validated. The isolation of the two analytes from blood was performed by liquid-liquid extraction with dichloromethane. Analysis was performed by Liquid Chromatography - Atmospheric Pressure Chemical Ionization - Mass Spectrometry (LC-APCI-MS). The method was applied on the determination of IMI and 6-ClNA in serum samples obtained from rabbits fed with the insecticide at two low doses. Furthermore, parameters of genotoxicity and cytotoxicity were evaluated by measuring binucleated cells with micronuclei (BNMN), micronuclei (MN) and the Cytokinesis Block Proliferation Index (CBPI), in lymphocytes of exposed rabbits. The results revealed a genotoxic effect of IMI for both exposed groups. There were statistically significant differences in the frequencies of BNMN and MN between control and exposed groups but there was no dose-dependence, neither time-dependence of the genotoxic effect for the administered doses. This is the first time that long term exposure to IMI in rabbits was studied for the determination of its genotoxic effect. The genotoxic effect of IMI as it is depicted by the current study is in accordance with previous studies.

Diethyl phosphates accumulation in rabbits’ hair as an indicator of long term exposure to diazinon and chlorpyrifos

Long term exposure to organophosphate pesticides can be evaluated by quantitative analysis of their non-specific metabolites in hair matrix. The aim of this study was to determine whether these metabolites can be internally incorporated into the hair of rabbits exposed to diazinon and chlorpyrifos. The influence of dose and dose duration of each pesticide dosage were investigated. Three groups of rabbits were exposed to different dosages of diazinon (3.0 and 6.0mg/kg/day) and chlorpyrifos (18.0mg/kg/day) via drinking water. Hair samples were collected every month and analyzed for diethyl phosphate (DEP) and diethyl thiophosphate (DETP) by gas chromatography-mass spectrometry (GC-MS). The mean concentrations of the low-dose treated group, ranged from 112 to 257pg/mg for DEP and from 295 to 515pg/mg for DETP in hair. The high-dose treated group demonstrated a range of mean concentrations from 142 to 585pg/mg for DEP and from 406 to 988pg/mg for DETP in hair. For the chlorpyrifos treated group, the concentrations ranged from 138 to 1070 for DEP and from 554 to 886pg/mg for DETP. Analysis revealed the incorporation of these metabolites into the rabbit hair in a dosage and dose duration-dependent manner. These data confirms the ability of using hair analysis for diethyl phosphates to assess long-term OP exposure.

Respiratory and immune response to maximal physical exertion following exposure to secondhand smoke in healthy adults.

We assessed the cardiorespiratory and immune response to physical exertion following secondhand smoke (SHS) exposure through a randomized crossover experiment. Data were obtained from 16 (8 women) non-smoking adults during and following a maximal oxygen uptake cycling protocol administered at baseline and at 0-, 1-, and 3- hours following 1-hour of SHS set at bar/restaurant carbon monoxide levels. We found that SHS was associated with a 12% decrease in maximum power output, an 8.2% reduction in maximal oxygen consumption, a 6% increase in perceived exertion, and a 6.7% decrease in time to exhaustion (P<0.05). Moreover, at 0-hours almost all respiratory and immune variables measured were adversely affected (P<0.05). For instance, FEV1 values at 0-hours dropped by 17.4%, while TNF-α increased by 90.1% (P<0.05). At 3-hours mean values of cotinine, perceived exertion and recovery systolic blood pressure in both sexes, IL4, TNF-α and IFN-γ in men, as well as FEV1/FVC, percent predicted FEV1, respiratory rate, and tidal volume in women remained different compared to baseline (P<0.05). It is concluded that a 1-hour of SHS at bar/restaurant levels adversely affects the cardiorespiratory and immune response to maximal physical exertion in healthy nonsmokers for at least three hours following SHS.

Differential micronuclei induction in human lymphocyte cultures by imidacloprid in the presence of potassium nitrate.

Humans are exposed to pesticides as a consequence of their application in farming or their persistence in a variety of media, including food, water, air, soil, plants, animals, and smoke. The interaction of pesticides with environmental factors may result in the alteration of their physicochemical properties. Square wave cathodic stripping voltammetry (SW-CSV), a technique that simulates electrodynamically the cellular membrane, is used to investigate whether the presence of potassium nitrate (KNO3) in the culture medium interferes with the genotoxic behavior of imidacloprid. The cytokinesis block micronuclei (CBMN) method is used to evaluate imidacloprids genotoxicity in the absence or presence of KNO3 in the culture medium and, as a consequence, its adsorption by lymphocytes. Comparing micronuclei (MN) frequencies in control and imidacloprid-treated blood cell cultures, statistically significant differences were not detected. KNO3 did not induce MN frequencies compared to control. Statistically significant differences in MN frequencies were observed when blood cell cultures were treated with imidacloprid in the presence of increasing concentrations of KNO3. SW-CSV revealed that by increasing KNO3 molarity, imidacloprids concentration in the culture medium decreased in parallel. This finding indicates that imidacloprid is adsorbed by cellular membranes. The present study suggests a novel role of a harmless environmental factor, such as KNO3, on the genotoxic behavior of a pesticide, such as imidacloprid. KNO3 rendered imidacloprid permeable to lymphocytes, resulting in elevated MN frequencies.

Bisphenol A in soft drinks and canned foods and data evaluation

ABSTRACT Bisphenol A (BPA) is one of the most common industrial chemicals and known to exert endocrine disruption activity. The aim of this study was the quantification of BPA in food stuffs on the Greek market. The applied liquid chromatography-mass spectrometry method was validated for linearity, limit of quantification, accuracy, precision and recovery. About 41.7% of the canned solid phase samples, 25.0% of the canned liquid phase samples and 43.8% of the soft drinks were positive. Mean BPA concentrations (range) were 33.4 ± 4.4 ng/g (4.90 ± 0.64–66.0 ± 8.6 ng/g) in canned solid phase, 2.70 ± 0.08 ng/ml (1.90 ± 0.06–3.50 ± 0.11 ng/ml) in canned liquid phase and 2.30 ± 0.18 ng/ml (0.40 ± 0.03–10.2 ± 0.8 ng/ml) in soft drinks. The results of this study are comparable with those reported in the literature according to which higher concentrations of BPA were detected in the solid fraction of canned food compared to their liquid fraction.

Downgrading the systemic condition of rabbits after long term exposure to cypermethrin and piperonyl butoxide.

AIM The aimof this study is to clarify the effect of cypermethrin (CY) on the oxidative stress (OS) and inflammation status of animals exposed to it and the synergistic role of piperonyl butoxide (PB0). MAIN METHODS Markers of oxidative stress, such as total antioxidant activity (TAC), protein carbonyls, hemoglobin (Hb), reduced glutathione (GSH), thiobarbituric-acid reactive substances (TBARS), along with the telomerase activity in PBMCs (peripheral blood mononuclear cells) were analyzed. KEY FINDINGS Oxidative stress markers showed statistically significant differences between groups in TAC (p b 0.001), GSH (p = 0.018) and CAT activity (p = 0.029), which depended on dose and combined effect of both compounds. Telomerase activity also showed a statistically significant difference between all groups (F = 43.48, df=6, 14, p b 0.001)with cypermethrin, piperonyl butoxide and the co-exposed groups being significantly different fromthe control group (p b 0.05). Significance: The observed results for TBARS, GSH, Hb, TAC, Crbnls and CAT from our exposed groups showed altered levels compared to control groups that could be linked to doses and combined effects of each chemical substance (cypermethrin and piperonyl butoxide). Oxidative stress markers suggest that cypermethrin, piperonyl butoxide and the co-exposed groups, induce oxidative stress as well as induction of telomerase activity.

Comparative Evaluation of Drug Deposition in Hair Samples Collected from Different Anatomical Body Sites

In this study, we focused on the validation of a method for the simultaneous detection and quantification of cannabinoids, cocaine and opiates in hair as well as on the distribution of the drugs deposition in hair collected from different anatomical body sites. The proposed analytical procedure was validated for various parameters such as selectivity, linearity, limit of quantification, precision, accuracy, matrix effect and recovery. Four hundred and eighty-one samples were collected during 2010-2015 from 231 drug abusers. A 6-h ultrasonic-assisted methanolic extraction was applied for the isolation of the drugs. The analysis was performed in an liquid chromatography-mass spectrometry system for the opiates and cocaine and in a gas chromatography-mass spectrometry system for the cannabinoids. Cocaine was the most frequent detected drug (68.8-80.5%) followed by cannabinoids (47.6-63.3%) and opiates (34.7-46.7%) depending on the body site that the samples were collected. The mean concentrations of Δ9-tetrahydrocannabinol (THC) were 0.63 ± 2.11 for head, 0.54 ± 1.03 for pubic, 0.34 ± 0.51 for axillary and 0.18 ± 0.18 ng/mg for chest hair samples. The values of cocaine were 6.52 ± 15.98, 4.64 ± 10.77, 6.96 ± 38.21 and 3.94 ± 6.35 ng/mg, while the values of 6-monoacetylmorphine (MAM) were 3.33 ± 5.89, 3.06 ± 9.33, 1.37 ± 1.37 and 16.4 ± 1.77 ng/mg for head, pubic, axillary and chest samples, respectively. Differences between the detected concentrations of cocaine and opiates between the hair samples of different anatomical sites, as well as the ratio of drug metabolites to the parent compounds were observed in some cases. Statistically significant differences in the mean detected levels were noticed for morphine and heroin between head and pubic hair and also for cocaine and benzoylecgonine, between head and axillary hair samples. Moreover, the ratio of MAM to morphine and THC to cannabinol seems to correlate statistically with the total opiate or cannabinoid detected concentrations. The above differences could be attributed to several parameters associated with the structure, morphology, growth rate and other characteristics of the collected hair.