toxicological evaluation of pouched portioned oral nicotine products.

Introduction: Modern oral nicotine pouch products (ONPs) are a category of oral nicotine products which contain pharmaceutical-grade nicotine, flavors, and other food-grade ingredients but no tobacco leaf. Recent reports indicate that ONPs in general do not contain (or only at minimal levels) the harmful and potentially harmful constituents (HPHCs) identified in cigarette smoke, suggesting their potential as alternative products for reducing harm from cigarette smoking.

Methods: We assessed toxicological effects of eight ONPs, designated as modern oral (MO) 1 to 8 along with an ONP, an oral tobacco (snus), and a combustible cigarette market comparator using established regulatory toxicological assays including Ames, micronucleus (ivMN), and neutral red uptake (NRU) assays.

In vitro toxicological evaluation of glo menthol and non-menthol heated tobacco products.

Heated tobacco products (HTPs) are non-combustible, inhaled tobacco products that generate an aerosol with fewer and lower levels of toxicants, with a potential to reduce risk relative to cigarette smoking. Here, we assessed in vitro toxicological effects of three menthol (glo neo neoCLICK, neo Smooth Menthol and Fresh Menthol) and one non-menthol (neo Smooth Tobacco) variants of glo HTP, along with market comparators for cigarettes and HTPs. Limited chemical characterization of the study products revealed significantly lower levels of acetaldehyde, acrolein, crotanaldehyde and formaldehyde in test samples from HTPs than those from cigarettes.

Evaluation of Cytotoxicity and Oxidative Stress of Whole Aerosol from Vuse Alto ENDS Products.

Assessment of in vitro cytotoxicity is an important component of tobacco product toxicological evaluations. However, current methods of regulatory testing involve exposing monolayer cell cultures to various preparations of aerosols from cigarettes or other emerging products such as electronic nicotine delivery systems (ENDS), which are not representative of human exposure. In the present study, a whole aerosol (WA) system was used to expose lung epithelial cultures (2D and 3D) to determine the potential of six Vuse Alto ENDS products that varied in nicotine content (1.

In vitro permeation of nicotine and tobacco specific nitrosamines from smokeless tobacco product extracts in a 3D buccal tissue model.

Tobacco product use is a risk factor in the development of oral cancer, although epidemiology studies show this risk is far less with smokeless tobacco product use than cigarette smoking. While smokeless tobacco contains harmful and potentially harmful constituents (HPHCs), the oral permeation of HPHCs in oral tobacco products is not completely understood. To improve the understanding, three different extract concentrations of the CORESTA reference products (CRP) for snus (CRP1.

Key Challenges and Recommendations for Testing of Tobacco Products for Regulatory Applications: Consideration of Test Materials and Exposure Parameters.

The Institute for In Vitro Sciences (IIVS) is sponsoring a series of workshops to identify, discuss and develop recommendations for optimal scientific and technical approaches for conducting assays, to assess potential toxicity within and across tobacco and various next generation nicotine and tobacco products (NGPs), including heated tobacco products (HTPs) and electronic nicotine delivery systems (ENDS). The third workshop (24-26 February 2020) summarised the key challenges and made recommendations concerning appropriate methods of test article generation and cell exposure from combustible cigarettes, HTPs and ENDS. Expert speakers provided their research, perspectives and recommendations for the three basic types of tobacco-related test articles: i) pad-collected material (PCM); ii) gas vapour phase (GVP); and iii) whole smoke/aerosol.

Characterization of smoke and aerosol deliveries from combustible cigarettes, heated tobacco products and electronic nicotine delivery systems in the Vitrocell® Mammalian 6/48 exposure module.

The rapid development associated with Next Generation Tobacco Products (NGTP) has necessitated the development of high throughput methodologies to test their genotoxic potential in vitro when compared to conventional cigarette smoke (CS). An assessment of two Vitrocell® Mammalian 6/48 exposure modules in three independent experiments was made by comparing results from multiple dosimetric techniques applied to aerosol generated from 3R4F Kentucky Reference cigarettes, commercially available electronically heated tobacco product (eHTP) and Electronic Nicotine Delivery System (ENDS) using the Vitrocell® VC10®. Real-time aerosol particle concentration was assessed by means of light scattering photometers and expressed as area under the curve (∑AUC).

A comparison of cigarette smoke test matrices and their responsiveness in the mouse lymphoma assay: A case study.

No cigarette smoke test matrix is without limitation, due to the complexity of the starting aerosol and phase to phase dynamics. It is impossible to capture all chemicals at the same level of efficiency, therefore, any test matrix will inadvertently or by design fractionate the test aerosol. This case study examines how four different test matrices derived from cigarette smoke can be directly compared.

KRAS Genotype Correlates with Proteasome Inhibitor Ixazomib Activity in Preclinical In Vivo Models of Colon and Non-Small Cell Lung Cancer: Potential Role of Tumor Metabolism.

In non-clinical studies, the proteasome inhibitor ixazomib inhibits cell growth in a broad panel of solid tumor cell lines in vitro. In contrast, antitumor activity in xenograft tumors is model-dependent, with some solid tumors showing no response to ixazomib. In this study we examined factors responsible for ixazomib sensitivity or resistance using mouse xenograft models.

Neuronal nicotinic receptor agonists ameliorate spontaneous motor asymmetries and motor discoordination in a unilateral mouse model of Parkinson's disease.

The degeneration of the nigrostriatal dopamine (DA) system underlies the motor deficits in Parkinson's disease (PD). In recent years, epidemiological reports that smokers have lower incidences of PD have brought attention to the nicotinic acetylcholine system as a potential target for novel therapeutics. Nicotine, an agonist of neuronal nicotinic receptors (NNRs), modulates functions relevant to PD via stimulation of dopaminergic transmission in the nigrostriatal pathway, particularly via activation of α6β2* and α4β2* NNRs.

TC-8831, a nicotinic acetylcholine receptor agonist, reduces L-DOPA-induced dyskinesia in the MPTP macaque.

Long-term L-DOPA treatment for Parkinson's disease (PD) is limited by motor complications, particularly L-DOPA-induced dyskinesia (LID). A therapy with the ability to ameliorate LID without reducing anti-parkinsonian benefit would be of great value. We assessed the ability of TC-8831, an agonist at nicotinic acetylcholine receptors (nAChR) containing α6β2/α4β2 subunit combinations, to provide such benefits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine- (MPTP) lesioned macaques with established LID.

Novel nicotinic acetylcholine receptor agonists containing carbonyl moiety as a hydrogen bond acceptor.

A novel series of α4β2 nAChR agonists lacking common pyridine or its bioisosteric heterocycle have been disclosed. Essential pharmacophoric elements of the series are exocyclic carbonyl moiety as a hydrogen bond acceptor and secondary amino group within diaza- or azabicyclic scaffold. Computer modeling studies suggested that molecular shape of the ligand also contributes to promotion of agonism.

α4β2 Nicotinic receptors play a role in the nAChR-mediated decline in L-dopa-induced dyskinesias in parkinsonian rats.

L-Dopa-induced dyskinesias are a serious long-term side effect of dopamine replacement therapy for Parkinson's disease for which there are few treatment options. Our previous studies showed that nicotine decreased l-dopa-induced abnormal involuntary movements (AIMs). Subsequent work with knockout mice demonstrated that α6β2* nicotinic receptors (nAChRs) play a key role.

Systemic administration of an alpha-7 nicotinic acetylcholine agonist reverses neuropathic pain in male Sprague Dawley rats.

Unlabelled: Alpha-7 nicotinic acetylcholine receptor (α7 nAChR) agonists attenuate pain and inflammation in preclinical models. This study tested whether systemic delivery of an α7 nAChR agonist attenuates neuropathic pain and associated immune-mediated pro-inflammation. Hind paw response thresholds to mechanical stimuli in male Sprague Dawley rats were assessed before and after sciatic chronic constriction injury (CCI) or sham surgery.

Analgesic effects mediated by neuronal nicotinic acetylcholine receptor agonists: correlation with desensitization of α4β2* receptors.

Nicotinic α4β2* agonists are known to be effective in a variety of preclinical pain models, but the underlying mechanisms of analgesic action are not well-understood. In the present study, we characterized activation and desensitization properties for a set of seventeen novel α4β2*-selective agonists that display druggable physical and pharmacokinetic attributes, and correlated the in vitro pharmacology results to efficacies observed in a mouse formalin model of analgesia. ABT-894 and Sazetidine-A, two compounds known to be effective in the formalin assay, were included for comparison.

Discovery of 3-(5-chloro-2-furoyl)-3,7-diazabicyclo[3.3.0]octane (TC-6683, AZD1446), a novel highly selective α4β2 nicotinic acetylcholine receptor agonist for the treatment of cognitive disorders.

Diversification of essential nicotinic cholinergic pharmacophoric elements, i.e., cationic center and hydrogen bond acceptor, resulted in the discovery of novel potent α4β2 nAChR selective agonists comprising a series of N-acyldiazabicycles.

Evolutionary history of novel genes on the tammar wallaby Y chromosome: Implications for sex chromosome evolution.

We report here the isolation and sequencing of 10 Y-specific tammar wallaby (Macropus eugenii) BAC clones, revealing five hitherto undescribed tammar wallaby Y genes (in addition to the five genes already described) and several pseudogenes. Some genes on the wallaby Y display testis-specific expression, but most have low widespread expression. All have partners on the tammar X, along with homologs on the human X.

Activity map of the tammar X chromosome shows that marsupial X inactivation is incomplete and escape is stochastic.

Background: X chromosome inactivation is a spectacular example of epigenetic silencing. In order to deduce how this complex system evolved, we examined X inactivation in a model marsupial, the tammar wallaby (Macropus eugenii). In marsupials, X inactivation is known to be paternal, incomplete and tissue-specific, and occurs in the absence of an XIST orthologue.

TC-5214 (S-(+)-mecamylamine): a neuronal nicotinic receptor modulator with antidepressant activity.

Both clinical and preclinical data support a potential therapeutic benefit of modulating the activity of CNS neuronal nicotinic receptors (NNRs) to treat depression and anxiety disorders. Based on the notion that the depressive states involve hypercholinergic tone, we have examined the potential palliative role of NNR antagonism in these disorders, using TC-5214 (S-(+) enantiomer of mecamylamine), a noncompetitive NNR antagonist. TC-5214 demonstrated positive effects in a number of animal models of depression and anxiety.

Therapeutic potential of novel selective drugs targeting nicotinic acetylcholine receptors.

The potential therapeutic benefit of nicotinic ligands in a variety of neurodegenerative pathologies involving the CNS has energized research efforts to develop nicotinic acetylcholine receptor (nAChR) subtype-selective ligands (Bencherif and Schmitt, 2005). In particular, there has been a concerted effort to develop nicotinic compounds with selectivity for CNS nAChRs as potential pharmaceutical tools in the management of these disorders. Clinical and experimental data demonstrate a central role for alpha7 and alpha4beta2 nAChRs in cognitive function, sensory processing, mood, and neuroprotection (Bencherif and Schmitt, 2005; Buccafusco et al.

Characterization of the discriminative stimulus effects of N-methyl- D-aspartate ligands under different ethanol training conditions in the cynomolgus monkey ( Macaca fascicularis).

Rationale: The current study was designed to extend our knowledge of the N-methyl- D-aspartate (NMDA) glutamate receptor system in mediating the discriminative stimulus effects of ethanol in non-human primates.

Objectives: To characterize the discriminative stimulus effects of the NMDA uncompetitive antagonists dizocilpine, phencyclidine (PCP) and ketamine in male and female monkeys under different ethanol training conditions.

Methods: Adult male ( n=8) and female ( n=9) cynomolgus monkeys ( Macaca fascicularis) were divided into four groups and trained to discriminate 1.

Evaluation of the carcinogenicity of 1,1-dichloroethylene (vinylidene chloride).

The U.S. Environmental Protection Agency has classified 1,1-dichloroethylene (vinylidene chloride; VDC) as a "C" carcinogen and has developed an inhalation unit risk value and an oral cancer slope factor for this chemical.