Proof of nicotine transfer to rat pups through maternal breast feeding to evaluate the neurobehavioral consequences of nicotine exposure

This study investigates the passage of nicotine from lactating dams to their offspring through breast milk in the frame of a research focused to ascertain toxicological and neuro-behavioural effects on pups as consequence of either unavoidable (“passive”) or voluntary (“active”) maternal nicotine exposure. To this aim, plasmatic concentrations of nicotine and cotinine were determined by LC-MS/MS in Wistar rat pups whose mothers were orally administered with nicotine during lactation. Mothers were divided into voluntary consumption group, unavoidable consumption group, and controls. The limits of detection and quantification of the LC-MS/MS method were 0.20 and 0.65 ng/mL, respectively. Within-laboratory reproducibility (CV%) was <10.0%, with recovery of 86.2-118.8%. Results showed the presence of nicotine in 67% of samples from voluntary consumption group (1.30±0.31 ng/mL) and in 60% of samples from “passive” consumption group (1.19±0.62 ng/mL); cotinine was found in all the samples from voluntary (1.92±0.77 ng/mL) and  “passive” consumption groups (1.43±0.30 ng/mL). Data provide an evidence-based support to maternal/offspring nicotine transfer as function of different ways of oral exposure

Forced but not free-choice nicotine during lactation alters maternal behaviour and noradrenergic system of pups. Impact on social behaviour of adolescent isolated male rats

Adverse effects of nicotine during pregnancy have been greatly studied, while nowadays few works are focused on consequences of maternal tobacco smoking after birth. The present study investigated the behavioral and early neurochemical effects of nicotine treatment during first weeks of post-natal life in rats. We used “free choice” treatment (H2O + NIC dams could drink from two bottles, containing 10 mg/L nicotine hydrogen tartrate salt, or water) versus “forced choice” (NIC + NIC mothers could drink from two bottles both containing nicotine hydrogen tartrate salt, range from 0.75 mg/L to 4.09 mg/L). We found that only “forced nicotine” had impact on maternal behavior, causing increased high-quality maternal care. This immediately impacted on neuro-chemical development, affecting NE levels (only males) in pup’s striatum and prefrontal cortex (pFC) at PND 12. After weaning, animals were reared in normal conditions (two brother rats) or in Social Isolation. After two weeks, they were tested with Social Interaction Test (isolated rats met non-isolated opponents, siblings vs. non-siblings). As expected, isolated rats displayed an aggressive form of soliciting behavior: when facing an isolated unknown partner, the non-isolated rat tried to escape. Interestingly, if their dams were exposed to forced nicotine, both rats sooner behaved very affiliative (possibly empathic) between non-sibling partners. As expected, being exposed to post-natal nicotine could alter neuro-chemical development, but with important interactions between both maternal care and adolescent social behavio

Chemical characterization of electronic cigarette (e-cigs) refill liquids prior to EU tobacco product directive adoption: Evaluation of BTEX contamination by HS-SPME-GC-MS and identification of flavoring additives by GC-MS-O

The present study focused on the determination of benzene, toluene, ethylbenzene and xylenes (BTEX) concentration levels in 97 refill liquids for e-cigs selected by the Italian National Institute of Health as representative of the EU market between 2013 and 2015 prior to the implementation of the European Union (EU) Tobacco Product Directive (TPD). Most of the e-liquids investigated (85/97) were affected by BTEX contamination, with few exceptions observed (levels below the limit of quantification (LOQ) of headspace-solid phase micro extraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) methodology). Across brands, concentration levels ranged from 2.7 to 30,200.0 μg/L for benzene, from 1.9 to 447.8 μg/L for ethylbenzene, from 1.9 to 1,648.4 μg/L for toluene and from 1.7 to 574.2 μg/L for m, p, o-xylenes. The variability observed in BTEX levels is likely to be related to the variability in contamination level of both propylene glycol and glycerol and flavoring additives included. No correlation was found with nicotine content. Moreover, on a limited number of e-liquids, gas chromatography-mass spectrometry-olfactometry (GC-MS-O) analysis was performed, allowing the identification of key flavoring additives responsible of specific flavor notes. Among them, diacetyl is a flavoring additive of concern for potential toxicity when directly inhaled into human airways. The data reported are eligible to be included in the pre-TPD database and may represent a reference for the ongoing evaluation on e-liquids safety and quality under the current EU Legislation

Evaluation of Second-Hand Exposure to Electronic Cigarette Vaping under a Real Scenario: Measurements of Ultrafine Particle Number Concentration and Size Distribution and Comparison with Traditional Tobacco Smoke

The present study aims to evaluate the impact of e-cig second-hand aerosol on indoor air quality in terms of ultrafine particles (UFPs) and potential inhalation exposure levels of passive bystanders. E-cig second-hand aerosol characteristics in terms of UFPs number concentration and size distribution exhaled by two volunteers vaping 15 different e-liquids inside a 49 m3 room and comparison with tobacco smoke are discussed. High temporal resolution measurements were performed under natural ventilation conditions to simulate a realistic exposure scenario. Results showed a systematic increase in UFPs number concentration (part cm&minus;3) related to a 20-min vaping session (from 6.56 &times; 103 to 4.01 &times; 104 part cm&minus;3), although this was one up to two order of magnitude lower than that produced by one tobacco cigarette consumption (from 1.12 &times; 105 to 1.46 &times; 105 part cm&minus;3). E-cig second-hand aerosol size distribution exhibits a bimodal behavior with modes at 10.8 and 29.4 nm in contrast with the unimodal typical size distribution of tobacco smoke with peak mode at 100 nm. In the size range 6&ndash;26 nm, particles concentration in e-cig second-hand aerosol were from 2- (Dp = 25.5 nm) to 3800-fold (Dp = 9.31 nm) higher than in tobacco smoke highlighting that particles exhaled by users and potentially inhaled by bystanders are nano-sized with high penetration capacity into human airways

Liquid chromatography with tandem mass spectrometry method for the determination of nicotine and minor tobacco alkaloids in electronic cigarette refill liquids and second-hand generated aerosol

A liquid chromatography with tandem mass spectrometry method for the simultaneous quantification of nicotine and seven minor tobacco alkaloids in both refill liquids for electronic cigarettes and their generated aerosol was developed and validated. The limit of detection and limit of quantification values were 0.3–20.0 and 1.0–31.8 ng/mL, respectively. Within-laboratory reproducibility was 8.2–14.2% at limit of quantification values and 4.8–12.7% at other concentration levels. Interday recovery was 75.8–116.4%. The method was applied to evaluate the compliance of commercial liquids (n = 95) with their labels and to assess levels of minor alkaloids. Levels of nicotine and its corresponding compounds were also evaluated in generated aerosol. About 47% of samples showed differences above ±10 % of the stated nicotine concentration. About 78% of the “zero nicotine” liquids showed traces in the range of 1.3 ± 0.1–254.0 ± 14.6 μg/mL. Nicotine-N′-oxides, myosmine, and anatabine were the most common minor alkaloids in liquids containing nicotine. Nicotine and N′-oxides were detected in all air samples when aerosol was generated from liquids containing nicotine. Nicotine average emissions from electronic cigarette (2.7 ± 0.9 μg/m3) were significantly lower (p < 0.01, t-test) with respect to conventional cigarette (30.2 ± 1.5 μg/m3)