Action Of Nicotine Research Articles

Neurobiological mechanisms of nicotine's effects on feeding and body weight.

Nicotine, a neuroactive substance in tobacco products, has been widely studied for its effects on feeding and body weight, mostly focusing on the involvement of nervous system, metabolism, hormones, and gut microbiota. To elucidate the action mechanism of nicotine on feeding and body weight, especially the underlying neurobiological mechanisms, we reviewed the studies on nicotine's effects on feeding and body weight by the regulation of various nerve systems, energy expenditure, peripheral hormones, gut microbiota, etc. The role of neuronal signaling molecules such as AMP-activated protein kinase (AMPK) and kappa opioid receptor (κOR) were specialized in the nicotine-regulating energy expenditure. The energy homeostasis-related neurons, pro-opiomelanocortin (POMC), agouti-related peptide (AgRP), prolactin-releasing hormone (Prlh), etc, were discussed about the responsibility for nicotine's effects on feeding. Nicotine's actions on hypothalamus and its related neural circuits were described in view of peripheral nervous system, reward system, adipose browning, hormone secretion, and gut-brain axis. Elucidation of neurobiological mechanism of nicotine's actions on feeding and body weight will be of immense value to the therapeutic strategies of smoking, and advance the medicine research for the therapy of obesity.

Expression of sensitized β2 nAChR subunits in VTA neurons enhances intravenous nicotine self-administration in male rats

Ventral tegmental area (VTA) nicotinic acetylcholine receptors (nAChRs) are important for nicotine reinforcement. To determine whether and to what extent these receptors are sufficient for nicotine reinforcement, we expressed β2Leu9′Ser (i.e. sensitized) nAChR subunits in the VTA of adult male rats and assessed the nicotine dose-response relationship in intravenous self-administration (SA). β2Leu9′Ser rats self-administered nicotine doses 50–100 fold lower than the lowest doses that control rats would respond for. Expression of WT β2 subunits confirmed that this enhanced sensitivity to nicotine was due to the Leu9′Ser mutation in β2. Higher unit doses were associated with strong escalation in β2Leu9′Ser rats over 17 fixed ratio sessions. Escalation was minimal or absent in control rats at the same unit doses. In progressive ratio SA, β2Leu9′Ser rats exhibited higher breakpoints than control rats when the nicotine unit dose was 1.5 μg/kg/inf or higher. In intermittent access SA, β2Leu9′Ser rats exhibited response patterns very similar to control rats. By adding nicotine dose-response data, progressive ratio assays, and intermittent access results that rule out stereotypy, these data significantly extend our previous finding that nicotine activation of the mesolimbic dopamine pathway is sufficient for nicotine reinforcement.

Nicotine aggravates pancreatic fibrosis in mice with chronic pancreatitis via mitochondrial calcium uniporter.

This study aimed to investigate the effects of nicotine on the activation of pancreatic stellate cells (PSCs) and pancreatic fibrosis in chronic pancreatitis (CP), along with its underlying molecular mechanisms. This was an in vivo and in vitro study. In vitro, PSCs were cultured to study the effects of nicotine on their activation and oxidative stress. Transcriptome sequencing was performed to identify potential signaling pathways involved in nicotine action. And the impact of nicotine on mitochondrial Ca2+ levels and Ca2+ transport-related proteins in PSCs was analyzed. The changes in nicotine effects were observed after the knockdown of the mitochondrial calcium uniporter (MCU) in PSCs. In vivo experiments were conducted using a mouse model of CP to assess the effects of nicotine on pancreatic fibrosis and oxidative stress in mice. The alterations in nicotine effects were observed after treatment with the MCU inhibitor Ru360. In vitro experiments demonstrated that nicotine promoted PSCs activation, characterized by increased cell proliferation, elevated α-SMA and collagen expression. Nicotine also increased the production of reactive oxygen species (ROS) and cellular malondialdehyde (MDA), exacerbating oxidative stress damage. Transcriptome sequencing revealed that nicotine may exert its effects through the calcium signaling pathway, and it was verified that nicotine elevated mitochondrial Ca2+ levels and upregulated MCU expression. Knockdown of MCU reversed the effects of nicotine on mitochondrial calcium homeostasis, improved mitochondrial oxidative stress damage and structural dysfunction, thereby alleviating the activation of PSCs. In vivo validation experiments showed that nicotine significantly aggravated pancreatic fibrosis in CP mice, promoted PSCs activation, exacerbated pancreatic tissue oxidative stress, and increased MCU expression. However, treatment with Ru360 significantly mitigated these effects. This study confirms that nicotine upregulates the expression of MCU, leading to mitochondrial calcium overload and exacerbating oxidative stress in PSCs, and ultimately promoting PSCs activation and exacerbating pancreatic fibrosis in CP.

Multifaceted Applications of Luminescent Metalloporphyrin Derivatives: Fluorescence Turn-On Sensing of Nicotine and Antimicrobial Activity.

In this study, we designed and synthesized metalloporphyrin derivatives (with Ni and Zn) specifically intended for the fluorescence detection of nicotine in aqueous solutions. Our results showcased a notable selectivity for nicotine over other naturally occurring food toxins, exhibiting an exceptional sensitivity with a limit of detection as low as 7.2 nM. Through mechanistic investigations (1H NMR, FT-IR, etc.), we elucidated the binding mechanism, revealing the specific interaction between the pyridine ring of nicotine and the metal center, while the N atom pyrrolidine unit engaged in the hydrogen bonding with the side chain of the porphyrin ring. Notably, we observed that the nature of the metal center dictated the extent of interaction with nicotine; particularly, Zn-porphyrin demonstrated a superior response compared to Ni-porphyrin. Furthermore, we performed the quantitative estimation of nicotine in commercially available tobacco products. Additionally, we conducted the antibacterial (Staphylococcus aureus and Escherichia coli) and antifungal (Candida albicans) activities of the porphyrin derivatives.

Neuronal Excitability in the Medial Habenula and Ventral Tegmental Area Is Differentially Modulated by Nicotine Dosage and Menthol in a Sex-Specific Manner.

The medial habenula (MHb) has been identified as the limiting factor for nicotine intake and facilitating nicotine withdrawal. However, few studies have assessed MHb neuronal excitability in response to nicotine, and, currently, a gap in knowledge is present for finding behavioral correlates to neuronal excitability in the region. Moreover, no study to date has evaluated sex or nicotine dosage as factors of excitability in the MHb. Here, we utilized an e-vape self-administration (EVSA) model to determine differences between sexes with different nicotine dosages ± menthol. Following this paradigm, we employed patch-clamp electrophysiology to assess key metrics of MHb neuronal excitability in relation to behavioral endpoints. We observed female mice self-administered significantly more than males, regardless of dosage. We also observed a direct correlation between self-administration behavior and MHb excitability with low-dose nicotine + menthol in males. Conversely, a high dose of nicotine ± menthol yields an inverse correlation between excitability and self-administration behavior in males only. In addition, intrinsic excitability in the ventral tegmental area (VTA) does not track with the amount of nicotine self-administered. Rather, they correlate to the active/inactive discrimination of mice. Using fast-scan cyclic voltammetry, we also observed that dopamine release dynamics are linked to reinforcement-related behavior in males and motivation-related behaviors in females. These results point to a sex-specific difference in the activity of the MHb and VTA leading to distinct differences in self-administration behavior. His could lend evidence to clinical observations of smoking and nicotine-use behavior differing between males and females.

Suppression by central adenosine A3 receptors of the cholinergic defense against cardiovascular aberrations of sepsis: role of PI3K/MAPKs/NFκB signaling.

Introduction: Despite the established role of peripheral adenosine receptors in sepsis-induced organ dysfunction, little or no data is available on the interaction of central adenosine receptors with sepsis. The current study tested the hypothesis that central adenosine A3 receptors (A3ARs) modulate the cardiovascular aberrations and neuroinflammation triggered by sepsis and their counteraction by the cholinergic antiinflammatory pathway. Methods: Sepsis was induced by cecal ligation and puncture (CLP) in rats pre-instrumented with femoral and intracisternal (i.c.) catheters for hemodynamic monitoring and central drug administration, respectively. Results: The CLP-induced hypotension, reduction in overall heart rate variability (HRV) and sympathovagal imbalance towards parasympathetic predominance were abolished by i.v. nicotine (100μg/kg) or i.c. VUF5574 (A3AR antagonist, 2µg/rat). In addition, the selective A3AR agonist, 3-iodobenzyl-5'-N-methylcarboxamidoadenosine IB-MECA, 4µg/rat, i.c.) exaggerated the hypotension and cardiac autonomic dysfunction induced by sepsis and opposed the favorable nicotine actions against these septic manifestations. Immunohistochemically, IB-MECA abolished the nicotine-mediated downregulation of NFκB and NOX2 expression in rostral ventrolateral medullary areas (RVLM) of brainstem of septic rats. The inhibitory actions of IB-MECA on nicotine responses disappeared after i.c. administration of PD98059 (MAPK-ERK inhibitor), SP600125 (MAPK-JNK inhibitor) or wortmannin (PI3K inhibitor). Moreover, infliximab (TNFα inhibitor) eliminated the IB-MECA-induced rises in RVLM-NFκB expression and falls in HRV, but not blood pressure. Conclusion: Central PI3K/MAPKs pathway mediates the A3AR counteraction of cholinergic defenses against cardiovascular and neuroinflammatory aberrations in sepsis.

An Updated Review of Nicotine in Gastrointestinal Diseases

Background: Nicotine addiction is a major risk for the population all over the world. Many gastrointestinal diseases are caused due to nicotine addiction, like peptic ulcers, inflammatory bowel diseases, and gastrointestinal cancer. Nicotine causes variations in the offensive and defensive factors, which are involved in gastrointestinal mechanisms. Objective: We aim to provide insights into nicotine activity in gastrointestinal disorders and cancer. Methods: Extensive literature was done using the keywords “Nicotine,” “Nicotine addiction,” “GI disorders,” “Peptic ulcer,” “Inflammatory bowel diseases,” and “Gastrointestinal cancer” from standard databases like PubMed, Scopus, Elsevier, and Science Direct. Conclusion: Thus, we may conclude that addiction to nicotine in peptic ulcers causes an increase of offensive factors and a decrease of defensive factors, and in gastrointestinal cancers, causes an increase in angiogenesis, metastasis, and proliferation and decrease in apoptosis in ulcerative colitis. It is used as treatment but worsens the condition of Crohn’s disease.

Identification and Characterization of Illegal Sales of Cannabis and Nicotine Delivery Products on Telegram Messaging Platform.

Unregulated and potentially illegal sales of tobacco, nicotine, and cannabis products have been detected on various social media platforms, e-commerce sites, online retailers, and the dark web. New end-to-end encrypted messaging services are popular among online users and present opportunities for marketing, trading, and selling of these products. The purpose of this study was to identify and characterize tobacco, nicotine, and cannabis selling activity on the messaging platform Telegram. The study was conducted in three phases: (1) identifying keywords related to tobacco, nicotine, and cannabis products for purposes of detecting Telegram groups and channel messages; (2) automated data collection from public Telegram groups; and (3) manual annotation and classification of messages engaged in marketing and selling products to consumers. Four keywords were identified ("Nicotine," "Vape," "Cannabis," and "Smoke") that yielded 20 Telegram groups with 262 506 active subscribers. Total volume of channel messages was 43 963 unique messages that included 3094 (7.04%) marketing/selling messages. The most commonly sold products in these groups were cannabis-derived products (83.25%, n = 2576), followed by tobacco/nicotine-derived products (6.46%, n = 200), and other illicit drugs (0.77%, n = 24). A variety of marketing tactics and a mix of seller accounts were observed, though most appeared to be individual suppliers. Telegram is an online messaging application that allows for custom group creation and global connectivity, but also includes unregulated activities associated with the sale of cannabis and nicotine delivery products. Greater attention is needed to conduct monitoring and enforcement on these emerging platforms for unregulated and potentially illegal cannabis and nicotine product sales direct-to-consumer. Based on study results, Telegram represents an emerging platform that enables a robust cannabis and nicotine-selling marketplace. As local, state, and national tobacco control regulations continue to advance sales restrictions and bans at the retail level, easily accessible and unregulated Internet-based channels must be further assessed to ensure that they do not act as conduits for exposure and access to unregulated or illegal cannabis and nicotine products.

Nicotine affects mitochondrial structure and function in human airway smooth muscle cells.

Exposure to cigarette smoke and e-cigarettes, with nicotine as the active constituent, contributes to increased health risks associated with asthma. Nicotine exerts its functional activity via nicotinic acetylcholine receptors (nAChRs), and the alpha7 subtype (α7nAChR) has recently been shown to adversely affect airway dynamics. The mechanisms of α7nAChR action in airways, particularly in the context of airway smooth muscle (ASM), a key cell type in asthma, are still under investigation. Mitochondria have garnered increasing interest for their role in regulating airway tone and adaptations to cellular stress. Here mitochondrial dynamics such as fusion versus fission, and mitochondrial Ca2+ ([Ca2+]m), play an important role in mitochondrial homeostasis. There is currently no information on effects and mechanisms by which nicotine regulates mitochondrial structure and function in ASM in the context of asthma. We hypothesized that nicotine disrupts mitochondrial morphology, fission-fusion balance, and [Ca2+]m regulation, with altered mitochondrial respiration and bioenergetics in the context of asthmatic ASM. Using human ASM (hASM) cells from nonasthmatics, asthmatics, and smokers, we examined the effects of nicotine on mitochondrial dynamics and [Ca2+]m. Fluorescence [Ca2+]m imaging of hASM cells with rhod-2 showed robust responses to 10 μM nicotine, particularly in asthmatics and smokers. In both asthmatics and smokers, nicotine increased the expression of fission proteins while decreasing fusion proteins. Seahorse analysis showed blunted oxidative phosphorylation parameters in response to nicotine in these groups. α7nAChR siRNA blunted nicotine effects, rescuing [Ca2+]m, changes in mitochondrial structural proteins, and mitochondrial dysfunction. These data highlight mitochondria as a target of nicotine effects on ASM, where mitochondrial disruption and impaired buffering could permit downstream effects of nicotine in the context of asthma.NEW & NOTEWORTHY Asthma is a major healthcare burden, which is further exacerbated by smoking. Recognizing the smoking risk of asthma, understanding the effects of nicotine on asthmatic airways becomes critical. Surprisingly, the mechanisms of nicotine action, even in normal and especially asthmatic airways, are understudied. Accordingly, the goal of this research is to investigate how nicotine influences asthmatic airways in terms of mitochondrial structure and function, via the a7nAChR.

Nicotine mediated epithelial modulations: An in-vitro evidence

IntroductionNicotine, the main ingredient in tobacco, acts as a key alkaloid of nearly all tobacco products and has been demonstrated to facilitate tumorigenesis and accelerate metastasis. Further traditional tobacco products have shown to give systemic oral effects such as vasoconstriction, inflammation, and delayed wound healing, however; none of the reports have confirmed the significant knowledge of oral sequel of the effect of nicotine on oral epithelial cells. So, the current study aimed to investigate the effect of nicotine on epithelial transformation to a malignant state. Material & methodsThrough in-vitro experiments, the effects of nicotine on epithelial cells obtained from nicotine never exposed buccal mucosa were analyzed using total count and viability test, proliferation assay, cell cycle distribution assay, and PI3K/MAPK dual pathway activation assay. Result & conclusionMTT assay demonstrated that the proliferation of epithelial cells takes place at a 150 mM concentration of nicotine. Further, we identified the significantly increased cell count and viability in nicotine-exposed cells. Further, cell cycle distribution assay results demonstrated that nicotine forced the epithelial cells to enter the first growth phase. The same influence of nicotine was observed on the PI3K/MAPK dual pathway activation assay where a greater number of nicotine exposed cells showed dual pathway activation. In conclusion, the current study determined the potential mechanism of action of nicotine on oral epithelial cell proliferation through activating the oncogenic pathway. This may help to develop novel therapeutic strategies for the prevention of malignant transformation from smokeless tobacco-caused oral cancer.

Pharmacokinetic and pharmacodynamic studies of nicotine in rat brain: a simultaneous investigation of nicotine metabolites and the release of neurotransmitters in vivo.

Introduction: The body's ability to metabolize nicotine and the disposition of nicotine in the brain are important determinants of its exposure. Limited knowledge about the near real-time changes of neurochemicals during the brain nicotine metabolic process hinders the recognition of its multiple neuropharmacological effects. Methods: An online microdialysis coupled with UHPLC-HRMS/MS method for the in vivo multi-analysis of nicotine metabolites and several neurotransmitters in rat brain was developed. Whether the systemic modulation of metabolic enzyme CYP2B would modulate nicotine pharmacokinetics and local neurochemical effects was further investigated. Results: The dynamic profiles of over 10 nicotine metabolites and neurotransmitters were simultaneously obtained after a single injection of nicotine (2mg·kg-1, i.p.) using the new method. Proadifen pretreatment (50mg·kg-1·d-1, i.p., 4days) caused significant inhibition of brain CYP2B1 activity. When exposed to nicotine, the brain C max of nicotine was 1.26 times higher and the levels of nicotine metabolites, nornicotine, and nicotine-N-oxide, were decreased by 85.3% and 34.4% in proadifen-pretreated rats. The higher level of brain nicotine induced a greater release of dopamine, serotonin, glutamate, and γ-amino-butyric acid in the nucleus accumbens. The concentrations of nicotine and dopamine were positively correlated, and the average levels of γ-amino-butyric acid and serotonin were 2.7 and 1.2 times higher, respectively, under the inhibition of nicotine metabolism. Discussion: These results demonstrated that inhibiting nicotine metabolism in rats can enhance the residence of brain nicotine and its local neurotransmitter effects. The metabolic activity of nicotine under different physiological conditions could regulate nicotine's bioavailability and its resulting pharmacology.

Evaluation of cyclooxygenase-2, P53, vascular endothelial growth factor, and nitric oxide synthase-2 in angiogenesis and growth of tobacco-related malignancies

Objectives: In India, tobacco consumption is responsible for half of all the cancers in men and a quarter in women. The present study focuses on the expression of cyclooxygenase-2 (COX-2), P53, vascular endothelial growth factor (VEGF), and nitric oxide synthase (NOS) and their relationship with the growth and angiogenesis of tobacco-related malignancies of the oral cavity, esophagus, lungs, and stomach. It further evaluates the carcinogenic action of nicotine and examines whether COX-2 and NOS-2 overexpression is responsible for tumor growth and associated angiogenic VEGF expression via its receptor. Materials and Methods: A cross-sectional study on 140 biopsies, resected specimens of cancer of oral cavity, esophagus, stomach, and lungs, was done. Immunohistochemical evaluation for p53, COX-2, VEGF, and inducible NOS was done. Relevant statistical analysis was applied for the significance of the findings. Statistical Analysis: Relevant statistical analysis was done using SPSS, chi-square and Fisher's exact tests were applied for the significance of the findings. A p-value of < 0.05 was considered as significant value. Results: Immunohistochemical evaluation of pattern of expression of COX-2, NOS-2, VEGF, and p53 was done in both tobacco- and nontobacco-associated cases. The results of the present study revealed an upregulation of COX-2, NOS-2, VEGF, and p53 in all the malignancies. Conclusion: The present results indicated that p53 protein accumulation and increased expression of COX-2, NOS-2, and VEGF might be responsible for carcinogenesis and tumor aggressiveness by enhancing angiogenesis. A possible significant effect of nicotine on COX-2 and P53 expression in tumorigenesis is revealed. These data might have important implications for the therapeutic use of COX-2, NOS-2, and VEGF inhibitors as well as of p53 gene therapy in future anticancer therapeutic strategies in tobacco-related malignancies.

Overlap in oncogenic and pro-inflammatory pathways associated with areca nut and nicotine exposure

BackgroundBetel nut/areca nut/Areca catechu is one of the most commonly used psychoactive substance, and is also a major preventable cause of cancer. Unlike other psychoactive substances, such as nicotine, the mechanisms underlying addiction to areca nuts and related oncogenesis remain elusive. Recent reports suggest a possible overlap in the mechanisms of action of nicotine and areca nuts in the human body. Thus, this study aimed to investigate the interactome of human proteins associated with areca nut exposure and the intricate similarities and differences in the effects of the two psychoactive substances on humans. MethodsA list of proteins associated with areca nut use was obtained from the available literature using terms from Medical Subject Headings (MeSH). Protein-protein interaction (PPI) networks and functional enrichment were analyzed. The results obtained for both psychoactive substances were compared. ResultsGiven the limited number of common proteins (36/226, 16%) in the two sets, a substantial overlap (612/1176 nodes, 52%) was observed in the PPI networks, as well as in Gene Ontology. Areca nuts mainly affect signaling pathways through three hub proteins (alpha serine/threonine-protein kinase, tumor protein 53, and interleukin-6), which are common to both psychoactive substances, as well as two unique hub proteins (epidermal growth factor receptor and master regulator of cell cycle entry and proliferative metabolism). Areca nut-related proteins are associated with unique pathways, such as extracellular matrix organization, lipid storage, and metabolism, which are not found in nicotine-associated proteins. ConclusionsAreca nuts affect regulatory mechanisms, leading to systemic toxicity and oncogenesis. Areca nuts also affect unique pathways that can be studied as potential markers of exposure, as well as targets for anticancer therapeutic agents.

Ghrelin Amplifies the Nicotine-Induced Release of Dopamine in the Bed Nucleus of Stria Terminalis (BNST).

Ghrelin is an orexigenic neuropeptide that is known for stimulating the release of growth hormone (GH) and appetite. In addition, ghrelin has been implicated in addiction to drugs such as nicotine. Nicotine is the principal psychoactive component in tobacco and is responsible for the reward sensation produced by smoking. In our previous in vitro superfusion studies, it was demonstrated that ghrelin and nicotine stimulate equally the dopamine release in the rat amygdala, and ghrelin amplifies the nicotine-induced dopamine release in the rat striatum. However, less attention was paid to the actions of ghrelin and nicotine in the bed nucleus of the stria terminalis (BNST). Therefore, in the present study, nicotine and ghrelin were superfused to the BNST of male Wistar rats, and the dopamine release from the BNST was measured in vitro. In order to determine which receptors mediate these effects, mecamylamine, a non-selective nicotinic acetylcholine receptor (nAchR) antagonist, and GHRP-6, a selective growth hormone secretagogue receptor (GHS-R1A) antagonist, were also superfused to the rat BNST. Nicotine significantly increased the release of dopamine, and this effect was significantly inhibited by mecamylamine. Ghrelin increased dopamine release even more significantly than nicotine did, and this effect was significantly inhibited by GHRP-6. Moreover, when administered together, ghrelin significantly amplified the nicotine-induced release of dopamine in the BNST, and this additive effect was reversed partly by mecamylamine and partly by GHRP-6. Therefore, the present study provides a new base of evidence for the involvement of ghrelin in dopamine signaling implicated in nicotine addiction.

Bioinformatic network analysis on the molecular interactions between Parkinson’s disease, alpha-synuclein, and infertility condition

BackgroundParkinson’s disease (PD) is a neurodegenerative condition that is characterized by a progressive decline of neural pathways, and its pathology is associated with alpha-synuclein abnormalities. Currently, infertility affects about 10% of individuals of fertile age within the USA. Interestingly, an increased length of fertility is associated with a decreased incidence of PD. Our study utilized QIAGEN’s Ingenuity Pathway Analysis (IPA) to identify and analyze molecular pathways that affect the underlying connection between alpha-synuclein (SNCA)-associated Parkinson’s disease (PD) and infertility condition (IC). Furthermore, we explored nicotine’s potential as a therapeutic in preventing the exacerbation of IC in terms of SNCA.ResultsAlthough the connection between SNCA-related PD and IC is not well explored, the Qiagen Knowledge Base (QKB) showed an overlap of 12 distinct molecules between SNCA and IC. These molecular pathways were established by adding SNCA and IC to “Pathway Explorer” and establishing connections to distinct molecules including transcription regulators, cytokines, and other enzymes/proteins. The Molecule-Activity-Predictor (MAP) tool predicted that SNCA activation would lead to an exacerbation of PD and IC with the potential involvement of dihydrotestosterone (DHT) and caspases. Specifically, it was found that SNCA decreased MAPK8 expression, which led to a downstream upregulation of IC. Activation of nicotine within this overarching molecular network resulted in a downregulation in both PD pathology and IC.ConclusionsTogether, these findings reveal a possible connection between infertility condition and genes regularly associated with alpha-synuclein-related Parkinson’s disease while identifying nicotine as a potential therapeutic application.Graphical

Nicotine perturbs the microbiota of brown planthopper (Nilaparvata lugens stål Hemiptera: Delphinidae)

Bacterial symbionts exhibiting co-evolutionary patterns with insect hosts play a vital role in the nutrient synthesis, metabolism, development, reproduction, and immunity of insects. The brown planthopper (BPH) has a strong ability to adapt to various environmental stresses and can develop resistance to broad-spectrum insecticides. We aimed to investigate whether gut symbionts of BPH play a major role in the detoxification of insecticides and host fitness in unfavorable environments. Nicotine-treated rice plants were exposed to BPH (early stage) and the gut microbiome of the emerging female adults were analyzed using high throughput sequencing (HTS). Nicotine administration altered the diversity and community structure of BPH symbionts with significant increases in bacterial members such as Microbacteriaceae, Comamondaceae, Enterobacteriaceae, and these changes may be associated with host survival strategies in adverse environments. Furthermore, the in-vitro study showed that four intestinal bacterial strains of BPH (Enterobacter NLB1, Bacillus cereus NL1, Ralstonia NLG26, and Delftia NLG11) could degrade nicotine when grown in a nicotine-containing medium, with the highest degradation (71%) observed in Delftia NLG11. RT-qPCR and ELISA analysis revealed an increased expression level of CYP6AY1 and P450 enzyme activities in Delftia NLG11, respectively. CYP6AY1 increased by 20% under the action of Delftia and nicotine, while P450 enzyme activity increased by 18.1%. After CYP6AY1 interference, nicotine tolerance decreased, and the mortality rate reached 76.65% on the first day and 100% on the third day. Moreover, Delftia NLG11 helped axenic BPHs to increase their survival rate when fed nicotine in the liquid-diet sac (LDS) feeding system. Compared with axenic BPHs, the survival rate improved by 25.11% on day 2% and 6.67% on day 3. These results revealed an altered gut microbiota and a cooperative relationship between Delftia NLG11 and CYP6AY1 in nicotine-treated BPH, suggesting that insects can adapt to a hostile environment by interacting with their symbionts and providing a new idea for integrated pest management strategies.

Nicotine promotes renal interstitial fibrosis via upregulation of XIAP in an alpha7-nAChR-dependent manner

Renal fibrosis, characterized by excessive accumulation of the extracellular matrix in the renal tubulointerstitium, can lead to chronic kidney disease (CKD), resulting in a heavy burden on families and society. Clinical studies have shown that smoking is closely associated with CKD deterioration in patients with diabetes, hypertension, polycystic kidney disease, and kidney transplantation. However, the mechanism of action of nicotine in renal fibrosis pathogenesis remains largely unknown. X-linked inhibitor of apoptosis (XIAP), a member of the inhibitor of apoptosis protein (IAP) family, is involved in apoptosis, necroptosis, autophagy, and immune response. Here, the upregulated expression of XIAP and α7 nicotine acetylcholine receptor (α7-nAChR) was determined in the kidneys of the CKD smoking group in human and animal studies. A significant positive correlation between XIAP and cotinine was observed. In addition, the nuclear translocation and transcriptional activity of SP1 were promoted when nicotine bound to α7-nAChR, resulting in XIAP overexpression and renal interstitial fibrosis progression. This phenotype can be reversed by the nicotine receptor subtype α7-nAChR antagonists methyllycaconitine. Our results revealed the complex underlying mechanism of nicotine in promoting renal fibrosis by altering SP1 nucleocytoplasmic translocation and regulating XIAP expression. These results provide novel insights into the pathogenesis and treatment of CKD.

Anti-Microbial Activity of Green Tea Extracts and Nicotine on the Growth, Biofilm Formation of Salivary Mutans Streptococci(In-vVtro Study)

الخلفية: الشاي الأخضر له نشاط مضاد للميكروبات ضد أنواع عديدة من البكتيريا ، ويعتبر مادة طبيعية ذات آثار جانبية قليلة. الهدف من الدراسة: أجريت دراسة في المختبر للتحقق من قدرة مستخلص الشاي الأخضر والنيكوتين على تثبيط النمو وتكوين الأغشية الحيوية بواسطة المكورات العقدية اللعابية. الطريقة العمل: تضمنت هذه الدراسة عينة ملائمة من 40 متطوعا عراقيا أصحاء تتراوح أعمارهم بين 18 و 23 عاما من كلية طب الأسنان / جامعة بغداد. تم تحضير الشاي الأخضر ومستخلص النيكوتين المائي بتركيز مختلف لاستخدامه في طريقة انتشار الآجار للكشف عن نشاط المستخلص ، وتم استخدام قارئ ELISA في لوحة متعددة العيار لتحديد قدرة المكورات العقدية اللعابية على تكوين غشاء حيوي في وجود وغياب المستخلصات لقياس معدل تثبيط الغشاء الحيوي. النتائج: كانت المكورات العقدية الطافرة حساسة للشاي الأخضر والنيكوتين بتركيزات مختلفة كانت أقطار منطقة التثبيط فعالة بطريقة تعتمد على الجرعة بشكل كبير. كان هناك فرق معنوي بين تراكيز كل مستخلص ، وكان النشاط المضاد للبكتيريا في طريقة تعتمد على الجرعة بالنسبة للمستخلصات. كان الحد الأدنى لتركيز مبيد الجراثيم للشاي الأخضر (280 مجم / مل) وأقل تركيز مبيد للجراثيم من النيكوتين (45 مجم / مل). ووجدت الدراسة أن تكوين الأغشية الحيوية بواسطة بكتيريا Mutans Streptococci انخفض بشكل ملحوظ في وجود 1/2 الحد الأدنى من تركيز مبيد الجراثيم لكل من الشاي الأخضر والنيكوتين بمتوسط ​​590 نانومتر = 0.54 مقارنة بمستخلصات الشاي الأخضر والنيكوتين وحده O.D 590 نانومتر = 0.15 ، 0.68 على التوالي. الاستنتاجات: مستخلصات الشاي الأخضر والنيكوتين بتركيزات مختلفة قللت بشكل فعال من تكوين الأغشية الحيوية للمكورات العقدية اللعابية. بينما أثر وجود النيكوتين سلبًا على قدرة مستخلصات الشاي الأخضر في تثبيط تكوين البيوفيلم بواسطة بكتيريا Mutans Streptococci في المختبر.

New medications development for smoking cessation

Diseases associated with nicotine dependence in the form of habitual tobacco use are a major cause of premature death in the United States. The majority of tobacco smokers will relapse within the first month of attempted abstinence. Smoking cessation agents increase the likelihood that smokers can achieve long-term abstinence. Nevertheless, currently available smoking cessation agents have limited utility and fail to prevent relapse in the majority of smokers. Pharmacotherapy is therefore an effective strategy to aid smoking cessation efforts but considerable risk of relapse persists even when the most efficacious medications currently available are used. The past decade has seen major breakthroughs in our understanding of the molecular, cellular, and systems-level actions of nicotine in the brain that contribute to the development and maintenance of habitual tobacco use. In parallel, large-scale human genetics studies have revealed allelic variants that influence vulnerability to tobacco use disorder. These advances have revealed targets for the development of novel smoking cessation agents. Here, we summarize current efforts to develop smoking cessation therapeutics and highlight opportunities for future efforts.

Electronic nicotine delivery systems (ENDS) aerosol constituent deposition and nicotine retention in the human oral cavity

Measurement of the dynamics and deposition of electronic nicotine delivery systems (ENDS) aerosols in the human oral cavity is challenging due to thermodynamic instabilities of the puff. We developed a mathematical model to predict ENDS aerosol puff mixture deposition and uptake in the oral cavity based on physical and physiological parameters, such as droplet/vapor phase change, coagulation, heat exchange between the puff and oral cavity, and puffing maneuver. We refined previous modeling efforts by incorporating improved assumptions for droplet growth, humidity evaluation, and temperature-dependent parameters to predict droplet deposition and vapor component uptake. We predicted dosimetry during puff withdrawal and mouth-hold of puff constituents that are present in droplets or vapor. These included water, nicotine, propylene glycol (PG), vegetable glycerin (VG), and two flavor chemicals (vanillin and benzaldehyde) which are representative of flavor chemicals with low and medium vapor pressures that undergo phase change at different rates. Model predictions indicated low droplet deposition (<2%) of the humectants PG and VG; PG vapor exhibited higher vapor uptake (∼14%). Deposition of nicotine in droplet form was low (<2%). Retention of nicotine in vapor form was sensitive to the nicotine activity coefficient and was predicted to be as high as 30%. Flavor chemical uptake was dependent on vapor pressure, with vanillin exhibiting negligible uptake and benzaldehyde exhibiting significant uptake (∼45%). ENDS constituent-specific dosimetry predictions in the oral cavity can inform an evaluation of the amounts entering the lungs and predict ENDS constituent levels associated with potential upper respiratory adverse effects. The dosimetry models presented here demonstrate their value as a practical tool for use by regulatory agencies and the risk assessment community to assess potential health impacts to ENDS users.