Would banning menthol cigarettes, flavored cigars, and flavored e-cigarettes prompt users to seek illicit channels for obtaining them in the United States?

BACKGROUND: Banning flavors in tobacco and nicotine products may reduce youth initiation and prompt quit attempts but such bans may lead to illicit markets. We examined how likely current users would be to seek flavored products from illicit channels under various ban scenarios. METHODS: Cross-sectional surveys of 2552 current users of menthol cigarettes or flavored cigars and 2347 users of flavored e-cigarettes were conducted between 2021 and 2022 in the United States. For each ban scenario, respondents reported if they would have intentions to seek the banned flavored products from any illicit channels and identified the specific illicit channel they would consider. Logistic regressions were used to estimate how the likelihood of having intentions to seek illicit channels was associated with demographics, ban scenarios, and status of tobacco use. RESULTS: Under various ban scenarios, 24-30% of people who smoked said they would seek illicit channels to obtain the banned products compared with 21-41% of dual users and 35-39% of users of flavored e-cigarettes. Online retailers were favored by people who smoked while users of flavored e-cigarettes favored local retailers. Heavy users were more likely to say they would try illicit channels. Under bans restricting more types of flavored tobacco products, users would be less likely to try illegal channels. CONCLUSIONS: A significant proportion of users of flavored tobacco and nicotine products would not reject using illicit banned products. Tailored programs are needed to apply to the groups with a higher risk of seeking illicit channels for banned products.

DFT Studies of the Activity and Reactivity of Limonene in Comparison with Selected Monoterpenes.

Nowadays, the effective processing of natural monoterpenes that constitute renewable biomass found in post-production waste into products that are starting materials for the synthesis of valuable compounds is a way to ensure independence from non-renewable fossil fuels and can contribute to reducing global carbon dioxide emissions. The presented research aims to determine, based on DFT calculations, the activity and reactivity of limonene, an organic substrate used in previous preparative analyses, in comparison to selected monoterpenes such as cymene, pinene, thymol, and menthol. The influence of the solvent model was also checked, and the bonds most susceptible to reaction were determined in the examined compounds. With regard to EHOMO, it was found that limonene reacts more easily than cymene or menthol but with more difficultly than thymol and pienene. The analysis of the global chemical reactivity descriptors "locates" the reactivity of limonene in the middle of the studied monoterpenes. It was observed that, among the tested compounds, the most reactive compound is thymol, while the least reactive is menthol. The demonstrated results can be a reference point for experimental work carried out using the discussed compounds, to focus research on those with the highest reactivity.

Prevalence of menthol cigarette use among adults who smoke from the United States by census division and demographic subgroup, 2002-2020: findings from the International Tobacco Control (ITC) project.

BACKGROUND: Targeted marketing of menthol cigarettes in the US influences disparities in the prevalence of menthol smoking. There has been no analysis of sub-national data documenting differences in use across demographic subgroups. This study estimated trends in the prevalence of menthol use among adults who smoke in the nine US census divisions by sex, age, and race/ethnicity from 2002 to 2020. METHODS: Data from 12 waves of the US ITC Survey were used to estimate the prevalence of menthol cigarette use across census divisions and demographic subgroups using multilevel regression and post-stratification (n = 12,020). Multilevel logistic regression was used to predict the prevalence of menthol cigarette use in 72 cross-classified groups of adults who smoke defined by sex, age, race/ethnicity, and socioeconomic status; division-level effects were fit with a random intercept. Predicted prevalence was weighted by the total number of adults who smoke in each cross-classified group and aggregated to divisions within demographic subgroup. Estimates were validated against the Tobacco Use Supplement to the Current Population Survey (TUS-CPS). RESULTS: Overall modeled prevalence of menthol cigarette use was similar to TUS-CPS estimates. Prevalence among adults who smoke increased in each division from 2002 to 2020. By 2020, prevalence was highest in the Middle (46.3%) and South Atlantic (42.7%) and lowest in the Pacific (25.9%) and Mountain (24.2%) divisions. Prevalence was higher among adults aged 18-29 (vs. 50+) and females (vs. males). Prevalence among non-Hispanic Black people exceeded 80% in the Middle Atlantic, East North Central, West North Central, and South Atlantic in all years and varied most among Hispanic people in 2020 (Pacific: 26.5%, New England: 55.1%). CONCLUSIONS: Significant geographic variation in the prevalence of menthol cigarette use among adults who smoke suggests the proposed US Food and Drug Administration (FDA) menthol cigarette ban will exert differential public health benefits and challenges across geographic and demographic subgroups.

The Effect of Menthol Mouth Rinsing and Fluid Temperature on Male Cycling Performance in Thermoneutral Conditions.

PURPOSE: The purpose of this study was to determine the effect of a menthol (MEN) mouth rinse (MR) on cycling time trial (TT) performance in thermoneutral conditions and to explore the impact of fluid temperature (cold water [CW] or thermoneutral water [TNW]) on MEN's effect on performance. METHODS: Twelve trained male cyclists (VO2 peak, 61.4 ± 12.1 mL/kg/min) completed a cycling TT in thermoneutral conditions (21 ± 0.2 °C, 40 ± 0.6% relative humidity) with four different mouth rinses: (1) MEN + CW; (2) MEN + TNW; (3) CW; and (4) TNW. The time to complete the TT and the power output (W) were recorded. The ratings of perceived exertion (RPE, Borg 6-20), thermal sensation (TS), and thermal comfort (TC) were recorded prior to and throughout the TT. The core body temperature (Tc) and heart rate (HR) were recorded throughout. RESULTS: The TT duration was not significantly different between trials (MEN + TNW: 38:11 ± 12:48, MEN + CW: 37:21 ± 13:00, CW: 38:12 ± 13:54, TNW: 36:06 ± 14:12 mins:secs, p < 0.05). The mean trial power output did not significantly differ between conditions (>0.05). The Tc, HR, RPE, TS, and TC were not significantly different between trials (p > 0.05). CONCLUSION: The results suggest that a MEN MR with either CW or TNW does not significantly improve cycling TT performance in trained male cyclists compared to a CW or TNW MR in thermoneutral conditions.

Examining the predictive utility of behavioral economic demand indices and subjective effects on the actualized reinforcing value of menthol cigarettes and potential alternatives.

INTRODUCTION: Considering recent and proposed bans on menthol cigarettes, methods are needed to understand the substitutability of potential menthol cigarette alternatives (MCAs) for menthol cigarettes. This study examined the prospective relationship between behavioral economic demand indices and subjective effects of usual brand menthol cigarettes (UBMC) and preferred MCAs with subsequent performance on a laboratory-based concurrent-choice task comparing UBMC and MCAs. METHODS: Eighty participants who typically smoked menthol cigarettes completed this clinical lab study. After sampling each product, participants completed the cigarette purchase task (CPT) and modified cigarette evaluation questionnaire (mCEQ). Following one-week of substituting their preferred MCA for their UBMC, participants completed a 90-min concurrent-choice self-administration task comparing their UBMC and preferred MCA. Linear regression models explored associations between CPT demand indices and mCEQ subjective effects in the lab with subsequent response effort for UBMCs on the concurrent-choice task. RESULTS: Three demand indices for UBMC were positively associated with UBMC response effort: Essential Value (EV; p=.02), Omax (p=.02), and breakpoint (p=.04). Four CPT demand indices for the preferred MCA significantly corresponded with UBMC response effort: EV (p=.03), Pmax (p=.04), Omax (p=.03), and breakpoint (p=.03). Subjective effects captured by the mCEQ were not associated with response effort. CONCLUSIONS: Demand indices reflecting Persistence (i.e., sensitivity to escalating price) predicted effort to obtain UBMC puffs on the concurrent-choice task. Among this sample, the CPT captured information on the relative reinforcing value (i.e., addiction potential) of combustible tobacco products similar to the longer self-administration task. IMPLICATIONS: In an ever-changing product market, assessing the reinforcing efficacy of menthol cigarettes and putative substitutes quickly and with validity is an important methodological tool for understanding abuse liability. Results suggest that behavioral economic demand indices of cigarette purchase task efficiently capture information on the relative reinforcing value of usual brand menthol cigarettes and plausible alternative tobacco products, similar to a 90-min in-laboratory self-administration task.

Menthol versus tobacco e-liquid flavor: Impact on acute subjective effects, puff patterns, and intentions for use among Black and White menthol smokers.

BACKGROUND: The proposed FDA product standard to prohibit menthol as a characterizing flavor in combustible cigarettes has the potential to significantly reduce tobacco-related health disparities. Whether a menthol e-liquid product standard would improve or hinder public health is unknown. No known research has directly examined the impact of menthol vs. tobacco flavored e-liquid use on acute e-cigarette use patterns, subjective experience, behavioral intentions, and craving and withdrawal among menthol cigarette smokers. METHODS: Black (n = 47) and White (n = 4) nicotine-deprived menthol smokers with limited e-cigarette experience completed two counterbalanced in-laboratory 30-minute ad libitum vaping sessions with menthol and tobacco nicotine salt-based e-liquid in a randomized crossover pilot trial design. Questionnaires assessed reductions in craving and withdrawal and post-session subjective experience and behavioral intentions. Puff topography was measured continuously throughout each vaping session. RESULTS: Measures of puff topography did not differ significantly by e-liquid flavor (all p > .40). Similarly, menthol and tobacco flavored e-cigarettes were both rated positively in terms of subjective effects and behavioral intentions (all p > .10) and about 40 % of participants reported a preference for the tobacco-flavored e-liquid. Finally, participants showed comparable reductions in craving (p = .210) and withdrawal (p = .671) from pre- and post-session regardless of e-liquid flavor. CONCLUSIONS: Among menthol smokers in a lab-based setting, findings suggest that menthol vs tobacco e-liquid flavor has little impact on acute changes in puff patterns, subjective experience, behavioral intentions, or craving and withdrawal.

Assessment of abuse liability and switching potential of menthol-flavored pod-based electronic nicotine delivery systems among US adults who smoke cigarettes.

BACKGROUND: Menthol-flavored electronic nicotine delivery systems (ENDS) are a focus of public health and regulatory policy considerations. The abuse liability of five menthol-flavored pod-based ENDS was compared to combustible cigarettes, and switching potential of ENDS was also evaluated. METHODS: 215 US adults who smoke cigarettes (34.4% female; mean age[SD]=29.60[8.75]; 40.9% non-Hispanic White; mean cigarettes/day[SD]=12.04[8.52]) completed a randomized 6-arm within-person cross-over product-use study. Participants used five pod-based menthol-flavored ENDS (JUUL2 Polar Menthol 1.5%, JUUL2 Prototype Fresh Menthol 3.0%, JUUL Menthol 5.0%, Vuse Alto Menthol 5.0%, NJOY Ace Menthol 5.0%) and their usual brand (UB) cigarette for 20minutes ad libitum. After each product use, subjective reinforcing effects relevant to abuse liability and associated with switching away from cigarettes (e.g., satisfaction, product liking) were assessed. RESULTS: All ENDS products were rated substantially and statistically significantly lower than UB cigarette on measures of subjective reinforcing effects (ps<0.001). Satisfying effects of JUUL2 1.5% were rated significantly higher than other ENDS products. JUUL2 Prototype 3.0% and Vuse Alto 5.0% did not significantly differ (ps>0.05), and both were rated significantly higher than JUUL 5.0% and NJOY Ace 5.0% (ps<0.05). Differences in subjective responses to study products did not significantly differ by preference for menthol cigarettes or by current ENDS use. CONCLUSIONS: Abuse liability of all menthol-flavored ENDS in this study was substantially lower than combustible cigarettes. Abuse liability of JUUL2 1.5% was within the range of currently marketed pod-based menthol-flavored ENDS products. JUUL2 1.5% likely has high potential for facilitating switching among US adults who smoke.

Stimulus mediation, specificity and impact of menthol in rats trained to discriminate puffs of nicotine e-cigarette aerosol from nicotine-free aerosol.

RATIONALE: It is unclear if e-cigarettes have reduced abuse liability relative to traditional cigarettes, especially when considering advanced devices which deliver nicotine more efficiently. Translatable and predictive animal models are needed to addresses this question. OBJECTIVES: Our goal was to explore the subjective stimulus effects of e-cigarettes by training rats to discriminate puffs of nicotine aerosol from vehicle aerosol using an aerosol delivery system designed to model e-cigarette use patterns in humans. METHODS: Rats were trained to discriminate between ten, 10 s puffs of aerosol generated from 3 mg/ml nicotine e-liquid and nicotine-free e-liquid using a food-reinforced operant procedure. Following acquisition, tests were conducted to determine the specificity of the nicotine aerosol stimulus as well as the impact to the stimulus effects of nicotine resulting from the addition of menthol to e-liquid. RESULTS: Rats learned the nicotine aerosol puff vs vehicle puff discrimination in a mean of 25 training sessions. Injected nicotine fully substituted for the stimulus effects of nicotine aerosol. The stimulus effects of nicotine aerosol were blocked by the nicotinic receptor antagonist mecamylamine. The nicotinic receptor partial agonist, varenicline as well as the stimulant d-amphetamine substituted more robustly for nicotine aerosol puffs than did the NMDA antagonist, ketamine. Menthol enhanced the stimulus effects of nicotine aerosol without altering nicotine blood plasma levels. CONCLUSIONS: Nicotine aerosol puffs can function as a training stimulus in rats. The stimulus effects were CNS-mediated and receptor specific. Menthol appears to enhance the stimulus effects of nicotine aerosol through a pharmacodynamic rather than pharmacokinetic mechanism.

Menthol Pretreatment Alleviates Campylobacter jejuni-Induced Enterocolitis in Human Gut Microbiota-Associated IL-10-/- Mice.

Human Campylobacter jejuni infections are of worldwide importance and represent the most commonly reported bacterial enteritis cases in middle- and high-income countries. Since antibiotics are usually not indicated and the severity of campylobacteriosis is directly linked to the risk of developing post-infectious complications, non-toxic antibiotic-independent treatment approaches are highly desirable. Given its health-promoting properties, including anti-microbial and anti-inflammatory activities, we tested the disease-alleviating effects of oral menthol in murine campylobacteriosis. Therefore, human gut microbiota-associated IL-10-/- mice were orally subjected to synthetic menthol starting a week before C. jejuni infection and followed up until day 6 post-infection. Whereas menthol pretreatment did not improve campylobacteriosis symptoms, it resulted in reduced colonic C. jejuni numbers and alleviated both macroscopic and microscopic aspects of C. jejuni infection in pretreated mice vs. controls. Menthol pretreatment dampened the recruitment of macrophages, monocytes, and T lymphocytes to colonic sites of infection, which was accompanied by mitigated intestinal nitric oxide secretion. Furthermore, menthol pretreatment had only marginal effects on the human fecal gut microbiota composition during the C. jejuni infection. In conclusion, the results of this preclinical placebo-controlled intervention study provide evidence that menthol application constitutes a promising way to tackle acute campylobacteriosis, thereby reducing the risk for post-infectious complications.

Investigating the role of nicotinic acetylcholine receptors in menthol's effects in mice.

The use of menthol in tobacco products has been linked to an increased likelihood of developing nicotine dependence. The widespread use of menthol can be attributed to its unique sensory characteristics; however, emerging evidence suggests that menthol also alters sensitivity to nicotine through modulation of nicotinic acetylcholine receptors (nAChRs). Nicotinic subunits, such as ß2 and α5, are of interest due to their implications in nicotine reward, reinforcement, intake regulation, and aversion. This study, therefore, examined the in vivo relevance of ß2 and α5 nicotinic subunits on the pharmacological and behavioral effects of menthol. Data suggests that the α5 nicotinic subunit modulates menthol intake in mice. Overall, deletion or a reduction in function of the α5 subunit lessened aversion to menthol. α5 KO mice and mice possessing the humanized α5 SNP, a variant that confers a nicotine dependence phenotype in humans, demonstrated increased menthol intake compared to their WT counterparts and in a sex-related fashion for α5 SNP mice. We further reported that the modulatory effects of the α5 subunit do not extend to other aversive tastants like quinine, suggesting that deficits in α5* nAChR signaling may not abolish general sensitivity to the aversive effects of other noxious chemicals. Further probing into the role of α5 in other pharmacological properties of menthol revealed that the α5 subunit does not modulate the antinociceptive properties of menthol in mice and suggests that the in vivo differences observed are likely not due to the direct effects of menthol on α5-containing nAChRs in vitro.

A randomized controlled trial of potential tobacco policies prohibiting menthol flavor in cigarettes and e-cigarettes: a study protocol.

BACKGROUND: Menthol cigarette use remains a large public health problem and disproportionately affects Black adults in the United States. The Food and Drug Administration has proposed prohibiting menthol flavor in cigarettes to protect public health. However, e-cigarettes are available in menthol flavor and are a popular alternative product adults might switch to if menthol is prohibited in cigarettes. Research is needed to understand how availability of menthol (vs. tobacco) flavored e-cigarettes could impact cigarette use among adults who smoke menthol cigarettes. METHODS: We will recruit 150 adults who currently smoke menthol cigarettes and will randomize them to 1 of 3 conditions modeling different regulatory scenarios. We will recruit equal numbers of participants identifying as Black vs. non-Black and will stratify randomization by race. To promote standardization and adherence, cigarette and e-cigarette products will be provided for 8 weeks based on the assigned condition: (A) no menthol restriction (menthol cigarette and menthol flavored e-cigarette), (B) menthol prohibited in cigarettes only (non-menthol cigarette and menthol flavored e-cigarette), (C) menthol prohibited in both cigarettes and e-cigarettes (non-menthol cigarette and tobacco flavored e-cigarette). A follow-up visit will occur at week 12 to assess tobacco use status. The study aims are to (1) examine the impact of prohibiting menthol flavor in cigarettes and e-cigarettes on smoking behavior and (2) investigate whether outcomes differ by race to understand the impact of menthol policies on Black (vs. non-Black) individuals given high rates of menthol cigarette use in this population. The primary outcome will evaluate changes in the number of cigarettes smoked per day during the 8-week study period and will examine differences by regulatory scenario. Secondary outcomes will compare percent days smoke-free, changes in nicotine dependence, and motivation, confidence, and intentions to quit smoking by the regulatory scenarios. We will examine whether changes in the outcomes differ by Black vs. non-Black participants to compare the magnitude of the effect of the various menthol policy scenarios by race. DISCUSSION: Results will contribute critical information regarding menthol in cigarettes and e-cigarettes to inform regulatory policies that maximize reductions in cigarette smoking and reduce tobacco-related health disparities. TRIAL REGISTRATION: NCT05259566. Yale IRB protocol #2000032211, last approved 12/8/2023.

Effects of mint, menthol, and tobacco-flavored e-cigarettes on tobacco withdrawal symptoms in adults who smoke menthol cigarettes: A laboratory pilot study.

BACKGROUND: Menthol cigarette smoking has remained stable or increased in certain groups, despite an overall decline in cigarette smoking rates in the U.S. Understanding whether e-cigarettes alter patterns of menthol cigarette use is critical to informing efforts for reducing the public health burden of menthol cigarette smoking. This 2019-2020 laboratory pilot study evaluated whether self-administration of mint-, menthol-, or tobacco-flavored e-cigarettes would differentially impact tobacco withdrawal symptoms in e-cigarette-naïve adults who smoke menthol cigarettes daily. METHODS: Participants (N=17; 35.3% Female; mean age=51.8) attended three laboratory sessions after 16-hours of tobacco abstinence. Participants self-administered a study-provided JUUL e-cigarette (0.7mL with 5% nicotine by weight) at each session in which flavor was manipulated (mint vs. menthol vs. tobacco; order randomized). Participants completed pre- and post-e-cigarette administration self-report assessments on smoking urges, nicotine withdrawal, and positive and negative affect states. Multilevel linear regression models tested differences between the three flavor conditions for individual study outcomes. RESULTS: Following overnight tobacco abstinence, vaping either a mint or menthol (vs. tobacco) flavored e-cigarette led to significantly greater reductions in smoking urges over time; menthol (vs. tobacco) flavored e-cigarettes also suppressed urges to smoke for pleasure. Notably, no differences in nicotine withdrawal, positive affect, or negative affect were observed. CONCLUSIONS: In this laboratory pilot study, mint and menthol (vs. tobacco) flavored e-cigarettes provided some negative reinforcement effects via acute reductions in smoking urges during tobacco abstinence, yet only menthol flavored e-cigarettes demonstrated suppressive effects on smoking urges for pleasure in adults who smoke menthol cigarettes daily.

Depolymerized carrageenan expresses elicitor-like activity on Mentha arvensis L. under arsenic stress: Insights into arsenic resilience and monoterpene synthesis.

Heavy metals contaminate agricultural land by limiting the productivity of crops and making them or their products unfit for consumption. Arsenic (As) is a potentially hazardous metalloid that severely impacts plants' survival. Menthol mint (Mentha arvensis L.) bears volatile compounds that are harshly exaggerated by diverse environmental factors like drought, salinity, heavy metal, temperature, photoperiod, and luminosity stresses. In this study, the phytotoxicity of As was examined in M. arvensis L. and its alleviation through the supplementation of oligomers of carrageenan. Noticeably, scanty information is available regarding the effect of irradiated carrageenan (ICA) on As-stressed plants. In order to observe the same in the case of M. arvensis L., the effect of ICA on As-treated plants was explored. The ICA concentration (foliar-applied) selected for the study was 80 mg L-1, 100 mg L-1 and 120 mg L-1, and that of As (soil-applied) was 80 mg kg-1 soil. Excess accumulation of As resulted in reduced growth, enzymatic activities, and yield and quality parameters of M. arvensis L. under As toxicity. However, the foliage application of ICA strengthens the antioxidant machinery and other physiological and oxidative stress biomarkers of the plant by facilitating the activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and proline, and, therefore aids in alleviating the toxicity generated by As. Nevertheless, ICA supplementation proves beneficial in enhancing the monoterpene synthesis (essential oil production and its active constituents) of M. arvensis L. by maintaining a steady-state equilibrium between reactive oxygen species (ROS) production and its scavenging process.

Menthol and related compounds in waterpipe products.

INTRODUCTION: The addition of cooling substances, such as menthol, might be attractive for youth to start smoking waterpipe by reducing the harshness of the smoke, thereby facilitating inhalation. These compounds simultaneously increase the addictiveness of tobacco and related products by stimulating nicotine uptake. Some menthol-like compounds also increase attractiveness by imparting a menthol/mint flavor. We provide an overview of the frequency and quantities of use of menthol-like substances in waterpipe tobacco, herbal molasses and steam stones. METHODS: The primary data source of this study was the European Common Entry Gate (EU-CEG). Product names and ingredients were obtained for 282 waterpipe tobacco products notified to The Netherlands in 2020. Subsequently, gas-chromatography-mass spectrometry (GC-MS) analysis was used to quantify seven menthol-like substances and nicotine in waterpipe tobacco (n=5), herbal molasses (n=1) and steam stones (n=12). RESULTS: Of the 282 EU-CEG-notified products, 39% have a menthol/mint declared flavor. GC-MS showed that 15 of the 18 investigated waterpipe products contained one or more menthol-like ingredients. GC-MS analysis showed that products termed 'freeze', 'ice' or 'mint' contained higher median menthol concentrations than products without these terms. CONCLUSIONS: Nearly all investigated waterpipe products contained menthol-like compounds, irrespective of their flavor. Such compounds are known to provide flavoring or cooling effects, and some are known to be carcinogenic. Our results can support the regulation of these substances in waterpipe products. Regulators should screen all waterpipe products, not only those with menthol or a similar indicator in product names.

The effect of menthol rinsing before intermittent exercise on physiological, physical, and thermo-behavioral responses of male football referees in hot and humid environment.

Introduction: In the current experiment, we aimed to evaluate whether eliciting pre-exercise non-thermal cooling sensations would alter perceptual measures, and physical and physiological responses in football referees. Methods: Nine highly trained male football referees undertook two 45-minute intermittent exercise protocols in hot and humid conditions (34.2 ± 0.6°C, 62.5 ± 1.0% relative humidity). In a randomized counterbalanced crossover design, 1 of 2 beverages were given before the warm-up: a 0.01% menthol solution or a placebo noncaloric solution. Physical performance was quantified as total distance covered in each of the three 15-minute exercise blocks. Core temperature, heart rate, thermal sensation and thermal comfort were measured at rest and after each exercise block. Results: No changes were observed between trials and over time for distance covered. No main effect of mouth rinse was observed for core temperature and heart rate, but both increased over time in all conditions (P < 0.001). Thermal sensation and thermal comfort were significantly improved with menthol after mouth-rinsing (P < 0.05), but with no differences at any other time-point. Discussion: These results indicate that non-thermal cooling oral stimuli provide immediate behavioral changes but may not influence physiological or physical responses in football referees, during intermittent exercise in hot and humid environments. Clinical Trial Registration: www.clinicaltrials.gov, identifier NCT05632692.

Efficient nanostructured materials to reduce nutrient leaching to overcome environmental contaminants.

Nutrient leaching is a major reason for fresh and ground water contamination. Menthol is the major bioactive ingredient of Mentha arvensis L. and one of the most traded products of global essential oil market. The indigenous production of menthol crystals in developing countries of the world can prove to be the backbone for local growers and poor farmers. Therefore, present research was designed to check the effects of nano-structured plant growth regulators (PGRs) (28-homobrassinolide and ethephon) with reduced leaching potentials on the essential oil and menthol (%) of Mentha arvensis L. The prepared nano-formulations were characterized by Fourier transform infrared (FTIR) spectroscopy, Laser induced breakdown spectroscopy (LIBS), Differential scanning colorimetry-thermal gravimetric analysis (DSC-TGA), Scanning electron microscopy (SEM), Atomic absorption spectrometry (AAS) and Zeta potential and Zeta size analysis. The menthol (%) was determined by modified spectrophotometric and gas chromatographic (GC) method. The highest essential oil (%) was obtained by the application of 28-homobrassinolide-Zn-NPs-L-II (0.92 ± 0.09%) and ethephon-Ca-NPs-L-III (0.91 ± 0.05%) as compared to the control (0.65 ± 0.03%) and blank (0.62 ± 0.09%). The highest menthol (%) was obtained by applying 28-homobrassinolide-Ca-NPs-L-I (80.06 ± 0.07%), 28-homobrassinolide-Ca-NPs-L-II (80.48 ± 0.09%) and 28-homobrassinolide-Ca-NPs-L-III (80.84 ± 0.11%) and ethephon-Ca-NPs-L-III (81.53 ± 0.17%) and ethephon-Zn-NPs-L-II (81.93 ± 0.26%) as compared to control (67.19 ± 0.14%) and blank (63.93 ± 0.17%).

How Cool is That? The Effects of Menthol Mouth Rinsing on Exercise Capacity and Performance: A Systematic Review and Meta-analysis.

BACKGROUND: Menthol (MEN) mouth rinsing (MR) has gained considerable interest in the athletic population for exercise performance; however, the overall magnitude of effect is unknown. OBJECTIVE: The aim of this systematic review and meta-analysis was to determine the efficacy of menthol MEN MR and the impact it has on exercise capacity and performance. METHODS: Three databases were searched with articles screened according to the inclusion/exclusion criteria. Three-level meta-analyses were used to investigate the overall efficacy of MEN MR and the impact it has on exercise capacity and performance. Meta-regressions were then performed with 1) mean VO2peak, 2) MEN swilling duration; 3) the MEN concentration of MR solution, 4) the number of executed swills throughout a single experiment, 5) the use of flavoured sweetened, non-caloric, or non-flavoured neutral solutions as controls, 6) mean environmental temperature at the time of exercise tests, and 7) exercise type as fixed factors to evaluate their influence on the effects of MEN MR. RESULTS: Ten MEN MR studies included sufficient information pertaining to MEN MR and exercise performance and capacity. MR with MEN resulted in no significant change in capacity and performance (SMD = 0.12; 95% CI - 0.08, 0.31; p = 0.23, n = 1, tau21 < 0.0001, tau22 = < 0.0001, I2 = 0%). No significant influence was detected in meta-regressions for VO2peak, (estimate: 0.03; df = 8; 95% CI - 0.03, 0.09; p = 0.27), swilling duration (5 vs. 10 s: 0.00; df = 16; 95% CI - 0.41, 0.41; p = 1.0), MEN concentration (low [0.01%] vs. high [0.1%]: - 0.08; df = 15; 95% CI - 0.49, 0.32; p = 0.67), number of swills (estimate: 0.02; df = 13; 95% CI - 0.05, 0.09; p = 0.56), the use of flavoured sweetener or non-caloric as control (non-flavoured vs. flavoured: 0.12; df = 16; 95% CI - 0.30, 0.55; p = 0.55) or mean room temperature during exercise tests (estimate: 0.01; df = 16; 95% CI - 0.02, 0.04; p = 0.62). CONCLUSION: MEN MR did not significantly improve overall exercise capacity and performance, though those involved in endurance exercise may see benefits.

Reduced menthol sensitivity in a prodromal Parkinson's disease model induced by intranasal rotenone treatment.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor symptoms, and it is associated with several prodromal non-motor symptoms, including an impaired sense of smell, taste and touch. We previously reported that bitter taste impairments occur independently of olfactory impairments in an early-stage PD animal model using short-term intranasal rotenone-treated mice. Cool temperatures also affect bitter taste perception, but it remains unclear whether or not bitter taste impairments result from an altered sensitivity for intraoral cool stimuli. We examined disturbances in the intraoral menthol sensitivity, such as coolness at low concentrations of menthol, using a brief-access test. Once a day, one solution from the 7-concentration series of (-)-menthol (0-2.3 mM) or the bitter taste quinine-HCl (0.3 mM) was randomly presented 20 times for 10 s to water-deprived mice before and 1 week after rotenone treatment. The total number of licks within 20 times was significantly decreased with the presentation of 2.3 mM menthol and quinine-HCl, compared to distilled water in untreated mice, but not in rotenone-treated mice. The correlation between the licks for quinine-HCl and that for menthol was increased after rotenone treatment. In contrast, the 2-bottle choice test for 48 h clarified that menthol sensitivity was increased after rotenone treatment. Furthermore, a thermal place preference test revealed that seeking behavior toward a cold-floored room was increased in the rotenone-treated mice despite the unchanged plantar cutaneous cold sensitivity. These results suggest that taste impairments in this model mice are at least partly due to intraoral somatosensory impairments, accompanied by peripheral/central malfunction.

Motivation to Quit Smoking Among Black Adults Residing in Los Angeles County Communities With Menthol Cigarette Sales Restrictions.

Background: Research is needed to identify the determinants of motivation to quit smoking among non-Hispanic Black (NHB) adults who smoke menthol cigarettes and reside in communities covered by menthol cigarette bans. Objectives: This study examined the associations between motivation to quit smoking and a range of individual-level predictors, including measures of demographics, harm/risk perception of menthol cigarettes, and awareness of a ban on menthol cigarettes in Los Angeles County unincorporated communities. Self-identified NHB adults who currently smoke menthol cigarettes (N=50; M=47.2 years; SD=13.7; 46% female) were recruited in Los Angeles County unincorporated communities. Participants completed an interviewer-administered cross-sectional survey between January to September 2021. Results: Participants (74%) reported an annual household income of less than $25,000. Participants' mean age at cigarette initiation was 15.7 years old (SD=5.68). Most (88%) were aware of the ordinance banning menthol cigarette sales. Employing multivariable linear regression analysis, harm/risk perception of menthol cigarettes (B=14.69, p<0.01) and awareness of the local menthol ban (B=26.18, p<0.05) were found to be independently associated with motivation to quit smoking. Conclusions: Findings from this community-based sample suggest that among NHB adults who smoke menthol cigarettes, motivation to quit smoking is influenced by their perception of menthol cigarettes as harmful and awareness of local policy banning the sale of menthol cigarettes. Findings underscore the need for community-centered and culturally grounded interventions to facilitate quitting among NHB adults who smoke in order for communities covered by menthol bans to achieve health equity in reducing preventable racial inequities due to menthol cigarettes.

Tobacco and menthol flavored nicotine-free electronic cigarettes induced inflammation and dysregulated repair in lung fibroblast and epithelium.

BACKGROUND: Electronic cigarette (e-cig) vaping has increased in the past decade in the US, and e-cig use is misleadingly marketed as a safe cessation for quitting smoking. The main constituents in e-liquid are humectants, such as propylene glycol (PG) and vegetable glycerine (VG), but different flavoring chemicals are also used. However, the toxicology profile of flavored e-cigs in the pulmonary tract is lacking. We hypothesized that menthol and tobacco-flavored e-cig (nicotine-free) exposure results in inflammatory responses and dysregulated repair in lung fibroblast and epithelium. METHOD: We exposed lung fibroblast (HFL-1) and epithelium (BEAS-2B) to Air, PG/VG, menthol flavored, or tobacco-flavored e-cig, and determined the cytotoxicity, inflammation, and wound healing ability in 2D cells and 3D microtissue chip models. RESULTS: After exposure, HFL-1 showed decreased cell number with increased IL-8 levels in the tobacco flavor group compared to air. BEAS-2B also showed increased IL-8 secretion after PG/VG and tobacco flavor exposure, while menthol flavor exposure showed no change. Both menthol and tobacco-flavored e-cig exposure showed decreased protein abundance of type 1 collagen α 1 (COL1A1), α-smooth-muscle actin (αSMA), and fibronectin as well as decreased gene expression level of αSMA (Acta2) in HFL-1. After tobacco flavor e-cig exposure, HFL-1 mediated wound healing and tissue contractility were inhibited. Furthermore, BEAS-2B exposed to menthol flavor showed significantly decreased tight junction gene expressions, such as CDH1, OCLN, and TJP1. CONCLUSION: Overall, tobacco-flavored e-cig exposure induces inflammation in both epithelium and fibroblasts, and tobacco-flavored e-cig inhibits wound healing ability in fibroblasts.