Effects of flavoring additives on feed intake, growth performance, temperament, and markers of immune function for newly received feedlot cattle.

Ninety Angus × Hereford steers (259.9 ±â€…36.18 kg body weight [BW]) were used in a 56-d experiment to assess the effects of flavoring additives on feed intake, and stress and immune response of newly received feedlot cattle. Steers were homogenously distributed by BW into six pens equipped with an individual feed intake monitoring system, and pen was randomly assigned to one of three treatments (15 heads per pen; 30 heads per treatment): a standard feedlot receiving diet (CT), or the same diet with a flavoring additive comprised of either sweeteners (Luctarom Feedlot, SW) or a mix of basic tastes (Luctarom Feedlot Mix, MX) at 1 kg/mT. Pens were equipped with a feed intake monitoring system, while BW, chute behavior, flight speed, blood and saliva samples were collected bi-weekly, and hair samples were collected at 4-wk intervals during the study. Data were analyzed using a mixed-effects model for a pen study using individual animal records with repeated measures. There was a treatment × week interaction (P < 0.01) where meal duration was greater in SW steers than MX and CT on week 3, and then CT on weeks 7 and 8. A trend for treatment × week interaction (P = 0.06) showed that the number of visits per day tended to be greater in SW than MX steers on weeks 4 and 5, and it tended to be greater in SW than MX and CT on week 5. The concentration of IL-6 was greater (P < 0.01) on days 1 and 28 than on day 14. The IgM concentration was greater (P < 0.01) on day 1 compared to days 14, 28, and 56. The concentration of haptoglobin was greater (P < 0.01) on 14 than days 28, 42, and 56, and it was greater (P < 0.01) on day 1 than days 42 and 56. The concentration of serum amyloid A was greater (P < 0.01) on day 1 compared to the rest of sampling days. Fibrinogen concentration was greater (P < 0.01) on day 1 compared to days 14 and 42. The neutrophil-to-lymphocyte ratio was greater (P < 0.01) on days 42 and 56 compared to days 1 and 28, and greater (P < 0.01) on day 14 compared to day 28. Hair and saliva cortisol concentrations were lower (P < 0.01) on day 56 compared to days 1 and 28, respectively. The use of flavoring additives, particularly when based on sweeteners (SW), caused some changes in the feeding pattern of newly received steers. These changes, however, were not consistent over the 56-d feeding period and were not accompanied by a change in growth performance, temperament, biomarkers of stress, inflammation, or immune function.

Feedlot-receiving calves are typically exposed to a series of stressful events, such as weaning, transportation, commingling, a change of environment, and illness, that have a negative impact on feed intake. The objective of this study was to assess the effects of feed flavors on feed intake, indicators of stress, and markers of the immune response for newly received feedlot cattle. Under the conditions of this study, the addition of flavoring agents showed some effects on the feeding pattern of newly arrived feedlot cattle, compatible with a positive hedonic response to the treatments. These effects, however, were limited to specific periods of time during the experiment and were not present when considering their performance over the whole 56-d feeding period. Furthermore, the addition of flavoring agents did not have a consistent effect on the concentration of inflammatory mediators, biomarkers of stress, or immune function. Future research should explore whether these or other flavoring agents, at different doses or used at different times, could cause biologically relevant effects to improve the resilience of calves during the feedlot receiving period.

Odor mixture perception during flavor consumption in rats.

Odor mixtures can be perceived as configural (i.e., different from their components) or elemental (i.e., similar to their components). Previous work demonstrates that these perceptual modes are determined by both peripheral and central interactions among mixture components. Flavor consumption is associated with unique peripheral and central odor processing mechanisms, but how this context affects perception of odor mixtures remains unknown. Here, we used a flavor consumption task in rats to measure preferences for solutions of binary odor mixtures and their components. In contrast to previous findings using identical mixtures in other contexts, our results demonstrate that rats employ elemental mixture processing strategies in the context of consumption. We discuss potential peripheral and central mechanisms that could explain unique mixture perception during consumption. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Palatable Flavoured Fluids without Carbohydrates and Electrolytes Do Not Enhance Voluntary Fluid Consumption in Male Collegiate Basketball Players in the Heat.

Using palatable fluids to enhance drinking in athletes who display insufficient compensatory hydration behaviour may mitigate the risks of hypohydration and performance deficits. However, it is unclear whether flavour can independently enhance fluid consumption. This study examined the effects of a colourless, artificially sweetened flavoured water (FW), without carbohydrates and with negligible amounts of sodium, compared to plain water (W) on fluid consumption in male collegiate basketball players in a practical game setting. Eighteen male basketball players (age 23.1 ± 1.3 years) played a 3v3 basketball small-sided game. The players were randomly assigned to consume either FW or W. Pre-game urine-specific gravity, fluid consumption, body mass, and hedonic taste perceptions were assessed. Basketball performance was analysed through notational analysis. Ratings of perceived exertion and thirst were recorded at pre-, post-game, and at each rest period. Heart rate was recorded throughout the gameplay. Despite significantly higher hedonic ratings for FW than W (6.78 ± 0.83 vs. 5.56 ± 1.33, p = 0.033, d = 1.36), there were no significant differences in fluid consumption (1083 ± 32 mL vs. 1421 ± 403 mL, p = 0.068, d = 0.92). Our result highlighted that using palatable fluids as a strategy to increase fluid consumption during high-intensity gameplay in the heat may not be effective if used without carbohydrates and electrolytes. Practitioners could consider both fluid palatability and composition in establishing a hydration plan for athletes.

Feasibility of Low-Sodium, High-Potassium Processed Foods and Their Effect on Blood Pressure in Free-Living Japanese Men: A Randomized, Double-Blind Controlled Trial.

We aimed to verify the effect of new low-sodium high-potassium seasonings and processed foods containing poly-γ-glutamic acid on blood pressure in free-living settings. To this end, we conducted a randomized, double-blind controlled trial on 187 Japanese men, aged 35-67 years, who did not use antihypertensives. Participants were randomly allocated to an intervention (n = 93) or a control group (n = 94). They were given a boxed lunch and miso soup (average Na and K content for the intervention group: 1175 and 1476 mg; for the control group: 2243 and 703 mg, respectively). Blood pressure was measured three times every morning for 1 week immediately before and during the final week of the trial. On the day before and the final day of the intervention period, 24 h urine samples were collected. After intervention, the intervention group showed a significantly stronger decrease in the urinary sodium-to-potassium ratio than the control group (p < 0.001). The mean difference in systolic blood pressure change after adjustment for baseline values between the two groups was -2.1 (95% CI: -3.6, -0.6) mmHg. Compliance between the groups was similar, suggesting successful blinding. In conclusion, the use of new seasonings and processed foods aimed at lowering blood pressure in free-living settings may be feasible and effective.

Cooling e-cigarette flavors and the association with e-cigarette use among a sample of high school students.

INTRODUCTION: E-liquid flavor is typically presented by flavor category (e.g. menthol, mint, fruit, dessert). Cooling sensations produced by flavor additives such as menthol enhance appeal of e-cigarettes among youth, but not all e-liquids that produce cooling sensations are labeled as menthol. Sensory experiences produced by flavors may allow for a new way to capture e-cigarette flavor use. This study aims to examine use of flavors that produce cooling sensations among youth and its association with e-cigarette use behaviors. METHODS: A 2019 survey of high school students (n = 4875) examined use of e-cigarette flavors that produced cooling sensations (cooling flavors) among past 30-day e-cigarette users. E-cigarette use behaviors (flavor use, nicotine use, frequency of use) were examined between those who did and did not use cooling flavors. A binary logistic regression was used to examine associations between vaping frequency, nicotine (vs. non-nicotine) use, and vaping cooling flavors while controlling for demographics, number of flavors vaped in the past month, and vaping age of onset. RESULTS: 51.6% (n = 473/916) of the analytic sample endorsed vaping cooling flavors. There were no demographic differences by vaping cooling flavors. Vaping cooling flavors was associated with vaping more frequently (AOR:1.04,95% CI:1.03,1.05) and vaping nicotine (AOR:2.37,95% CI:1.53,3.67). CONCLUSION: Vaping cooling flavors was associated with greater nicotine vaping and frequency of e-cigarette use. Assessing sensory experience, such as cooling, in addition to flavor category may more fully capture e-cigarette flavor use and its impacts on youth e-cigarette use behaviors.

Evaluación semicuantitativa de los microelementos del esmalte en un modelo de obesidad inducido por glutamato monosódico en ratas / Semi-quantitative evaluation of enamel microelements in an obesity model induced by monosodium glutamate in rats

RESUMEN: En la actualidad, existen múltiples modelos experimentales de obesidad, unos de ellos es la utilización de glutamato monosódico (GMS), un potenciador del sabor ampliamente utilizado en industria alimentaria. Este GMS ha sido relacionado con obesidad, diabetes, insulino resistencia, así como en alteraciones en múltiples órganos, tales como testículos, riñón e hígado, entre otros. Ha sido reportado el efecto del GMS en estructuras orales, tales como las glándulas salivales, alterando su morfología y función. La relación del efecto del GMS frente a tejidos dentarios no ha sido reportada, siendo esto relevantes debido a la información que proporciona a disciplinas tales como arqueología científica, identificación forense, paleoecología y odontología. El objetivo del estudio fue observar la modificación de los elementos en la superficie dental, en un modelo de obesidad inducida por GMS, en ratas. Se utilizaron 12 ratas neonatas Sprague Dawley machos, divididas en dos grupos según exposición a GMS (Grupo Control y Grupo GMS 1: 4 mg/g peso de GMS, 5 dosis, mantenidas 16 semanas. Fue calculado el índice de masa corporal (IMC) e Índice de Lee, además de ser analizados el porcentaje de masa de los elementos C, O, Na, P, Ca, Fe y K en la superficie dental, mediante análisis semicuantitativo. Los resultados indican que GMS indujo obesidad en las ratas, así como alteraciones en los porcentajes de masa de los elementos en la superficie dental, evidenciándose disminución de Ca, P y O, además de aumentos en C y Fe. Según reportes previos, la obesidad inducida por GMS, causa alteraciones en secreción y composición salival, elemento íntimamente relacionado con la composición del esmalte, lo que vendría a explicar nuestros resultados. Entender la composición superficial del esmalte superficial podría ayudarnos a comprender de mejor manera la relación entre caries dentaria y obesidad.

SUMMARY: Monosodium glutamate (MSG) is a flavor enhancer widely used in the food industry. It has been associated with obesity, diabetes, insulin resistance, as well as alterations in multiple organs, such as testicles, kidney, liver, among others. While its effect on oral structures such as the salivary glands has been reported, the impact on dental tissues has not been described. Since this information is also relevant in fields such as forensic identification, palaeoecology and dentistry, the objective of the study was to observe alterations on the tooth surface in a model of obesity in rats induced by MSG. Twelve neonate male Sprague Dawley rats were used, divided into two groups according to MSG exposure (Control Group and MSG1 Group: 4 mg / g weight of MSG, 5 doses were maintained for 16 weeks. Body mass index (BMI) and Lee's index as well as mass percentage of elements C, O, Na, P, Ca, Fe and K on the tooth surface were evaluated by semi-quantitative analysis. In addition to increases in C and Fe, results indicate that MSG induced obesity and alterations in the percentages of mass on the tooth surface in rats, showing a decrease in Ca, P and O, According to previous reports, MSG induced obesity causes alterations in secretion and salivary composition, an aspect closely related to enamel composition, thus explaining our results. Enhanced knowledge of enamel surface composition may help improve our understanding of the relationship between dental caries and obesity.

Appeal, subjective effects, and relative reinforcing effects of JUUL that vary in flavor and nicotine content.

The U.S. Food and Drug Administration has the authority to regulate characteristics of electronic nicotine delivery systems (ENDS). Prior research indicates that regulation of certain characteristics of these products may have an effect on their appeal and use. Policies that affect appeal and use of ENDS are relevant to attempts to reduce use among young people-including young adults-but are also relevant to adults who use these products as harm reduction tools. Using a novel concurrent choice task, we evaluated the relative reinforcement of JUUL brand ENDS products that varied in flavor (n = 8) and nicotine (n = 8) among samples of young adults who use JUUL. Findings suggest that restricting JUUL flavor to tobacco-only results in decreased appeal, while reducing the nicotine content of JUUL pods to 3%-from the conventional 5%-does not have an effect on product appeal. Findings also validate a novel methodology for delivering fixed doses of ENDS vapor within the context of a task that assesses the relative reinforcement of ENDS products with varying characteristics. This methodology can be applied to assessing the relative reinforcing effects of a wide variety of tobacco products with varied characteristics. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Availability of a Flavored Beverage and Impact on Children's Hydration Status, Sleep, and Mood.

Euhydration remains a challenge in children due to lack of access and unpalatability of water and to other reasons. The purpose of this study was to determine if the availability/access to a beverage (Creative Roots®) influences hydration in children and, therefore, sleep quality and mood. Using a crossover investigation, 46 participants were randomly assigned to a control group (CON) or an intervention group and received Creative Roots® (INT) for two-week periods. We recorded daily first morning and afternoon urine color (Ucol), thirst perception, and bodyweight of the two groups. Participants reported to the lab once per week and provided first morning urine samples to assess Ucol, urine specific gravity (USG), and urine osmolality (Uosmo). Participants also completed the questionnaires Profile of Mood States-Adolescents (POMS-a) and Pittsburgh Sleep Quality Index (PSQI). Dependent t-tests were used to assess the effects of the intervention on hydration, mood, and sleep quality. Uosmo was greater and Ucol was darker in the control group (mean ± SD) [Uosmo: INT = 828 ± 177 mOsm·kg-1, CON = 879 ± 184 mOsm·kg-1, (p = 0.037], [Ucol:INT = 5 ± 1, CON = 5 ± 1, p = 0.024]. USG, POMS-a, and PSQI were not significant between the groups. At-home daily afternoon Ucol was darker in the control group [INT = 3 ± 1, CON = 3 ± 1, p = 0.022]. Access to Creative Roots® provides a small, potentially meaningful hydration benefit in children. However, children still demonstrated consistent mild dehydration based on Uosmo, despite consuming the beverage.

Exposure to fruit-flavoring during adolescence increases nicotine consumption and promotes dose escalation.

The rise of e-cigarette popularity has sparked interest in the role of palatable flavors on nicotine use. Despite growing evidence that sweet flavorants enhance nicotine reward, their influence on nicotine consumption has not been studied extensively. In addition, the impact that flavored nicotine use in adolescence could have on nicotine reward and dependence in adulthood remains unclear. This study examined the role of flavored nicotine access on nicotine preference and consumption longitudinally, from adolescence to adulthood. Male and female adolescent mice preferred a fruit-flavored nicotine solution over an unflavored nicotine solution. However, only adolescent female mice with access to flavored nicotine consumed higher doses. Furthermore, while adolescent male mice escalated consumption of both flavored and unflavored nicotine, female mice only escalated nicotine consumption when given access to flavored nicotine. As mice matured into adulthood, there was no evidence that a history of flavored-nicotine access altered preference for unflavored nicotine compared to a nicotine-free control in a classic two-bottle choice design. However, when the nicotine concentration was progressively reduced, mice that had consumed strawberry-flavored nicotine in adolescence maintained baseline nicotine consumption levels longer than mice that initiated nicotine use without flavor in adolescence. Finally, addition of fruit-flavorants into the nicotine solution during adulthood led to nicotine preference and increased levels of nicotine consumption, regardless of previous flavored-nicotine access or of familiarity with the selected flavorant. These results indicate that flavorants increase nicotine consumption independent of life stage, possibly posing a disproportionate risk to adolescent females. Our results also point to an effect of adolescent flavored-nicotine use on nicotine dose maintenance in adulthood, which could have implications for the success of future quit attempts.

Influence of a prebiotic and natural sweeteners on the sensory profile of skyr yogurt with mango pulp.

Skyr yogurts have been gaining prominence because of their different sensory characteristics. Due to their healthy appeal, the use of natural sweeteners to replace sucrose in this type of yogurt can be an alternative for incorporating a sweet taste, in addition to increasing the functionality of the product through the incorporation of prebiotics. This study aimed to determine whether the addition of fructooligosaccharide (FOS), sucrose, stevia, and thaumatin affects the sensory profile of the skyr yogurt with mango pulp and its acceptance in two Brazilian regions. Eight formulations of skyr with mango pulp were developed. The compositional parameters evaluated were moisture, protein, lipids, ash, and carbohydrate. The tests performed were ideal sweetness and mango flavor, sweetness equivalence for each sweetener used, Quantitative Descriptive Analysis (QDA), and consumer testing in the Southeast and Northeast regions of Brazil. In general, the addition of FOS did not impact the characteristics of the formulated skyr yogurt. The type of sweetener had an impact on the sensory profile and acceptance of the skyr yogurt, affected characteristics such as mango flavor, sweet taste, sweet aftertaste, bitter taste, bitter aftertaste, and metallic flavor. The results of the affective test demonstrated that, for consumers in the Southeast, mango flavor is a positive attribute in this yogurt, and for Northeastern consumers, in addition to mango flavor, sweetness must also be taken into consideration. PRACTICAL APPLICATION: This study may be useful for the dairy industry because in the literature, there is still a lack of sensory studies of skyr yogurt, especially when sucrose substitutes are used. The results of the consumer test in this work reinforce the importance of studies related to consumer preferences with cultural differences.

Flavor additives facilitate oral self-administration of nicotine solution in mice.

RATIONALE: Tobacco products are very addictive, partly because they contain nicotine which is reinforcing, but also because they include appealing aromas and tastes. Flavor additives are such sensory stimuli which enhance attractiveness, as well as use and abuse of tobacco and vaping products. Yet, the interaction between these flavor additives and nicotine remains poorly understood. OBJECTIVES: We want to understand how flavors may reduce nicotine' aversive taste and how it may enhance its voluntary oral self-administration in mice. METHODS: We first studied the effect of flavor additives on nicotine solution palatability in a free bottle choice paradigm. Second, we investigated the effect of vanilla flavoring on the different stages of nicotine (40 µg/ml) oral self-administration in mice. RESULTS: We show that adding flavors increase nicotine palatability and facilitate acquisition and maintenance of oral self-administration when compared to nicotine-alone group. Mice adapt their operant behavior depending on changes in nicotine concentration. All mice reinstate nicotine seeking upon presentation of associated cues. Nevertheless, vanilla-flavored nicotine was not more reinforcing than vanilla-flavored water which was reinforcing enough to drive similar operant response rates. CONCLUSIONS: Flavor additives increase nicotine oral consumption and help maintaining operant behavior in mice. Moreover, flavors can be very attractive and can have high reinforcing value by themselves. Thus, it is crucial that the investigation on how taste signals play an important role in modulating oral nicotine intake in rodent models remains explored.

Inhibition of Bitter Taste from Oral Tenofovir Alafenamide.

Children have difficulty swallowing capsules. Yet, when presented with liquid formulations, children often reject oral medications due to their intense bitterness. Presently, effective strategies to identify methods, reagents, and tools to block bitterness remain elusive. For a specific bitter-tasting drug, identification of the responsible bitter receptors and discovery of antagonists for those receptors can provide a method to block perceived bitterness. We have identified a compound (6-methylflavone) that can block responses to an intensely bitter-tasting anti-human immunodeficiency virus (HIV) drug, tenofovir alafenamide (TAF), using a primary human taste bud epithelial cell culture as a screening platform. Specifically, TAS2R39 and TAS2R1 are the main type 2 taste receptors responding to TAF observed via heterologously expressing specific TAS2R receptors into HEK293 cells. In this assay, 6-methylflavone blocked the responses of TAS2R39 to TAF. In human sensory testing, 8 of 16 subjects showed reduction in perceived bitterness of TAF after pretreating (or "prerinsing") with 6-methylflavone and mixing 6-methylflavone with TAF. Bitterness was completely and reliably blocked in two of these subjects. These data demonstrate that a combined approach of human taste cell culture-based screening, receptor-specific assays, and human psychophysical testing can successfully discover molecules for blocking perceived bitterness of pharmaceuticals, such as the HIV therapeutic TAF. Our hope is to use bitter taste blockers to increase medical compliance with these vital medicines. SIGNIFICANCE STATEMENT: Identification of a small molecule that inhibits bitter taste from tenofovir alafenamide may increase the compliance in treating children with human immunodeficiency virus infections.

A 90-day subchronic toxicity study of 5-methyl-2-phenyl-2-hexenal in F344 rats.

5-Methyl-2-phenyl-2-hexenal (MPH) has been used as a flavoring agent. In the present study, we performed a subchronic toxicity study in male and female F344 rats with oral administration of MPH by gavage at 0, 8, 24 and 70 mg/kg body weight (BW)/day for 90 days. No mortality or clinical signs were observed during the experimental period. Body weight and food consumption for all treated groups of both sexes were essentially the same as for the respective control groups. Hematologic examination demonstrated significant decreases in monocyte counts for females given 24 and 70 mg/kg BW/day. However, these changes were not substantial and no related histopathological changes were observed, suggesting that these changes were not toxicologically significant. Among organ weights, the absolute and/or relative weights of testes and liver were significantly increased in the 70 mg/kg BW/day groups of males and females, respectively, but no related histopathological changes were observed, suggesting that these changes did not reflect adverse effects. In addition, no treatment-related histopathological changes were observed for any of the tissues examined. Based on the overall data, the no-observed-adverse-effect level (NOAEL) for MPH was determined to be 70 mg/kg BW/day, the highest dose tested, in both male and female rats.

Effect of locust bean gum-sodium alginate coatings incorporated with daphnetin emulsions on the quality of Scophthalmus maximus at refrigerated condition.

In this study, the microbiological, physicochemical, and flavor changes of turbot (Scophthalmus maximus) coated with a composite active coating of locust bean gum (LBG) and sodium alginate (SA) supplemented with daphnetin emulsions (0.16, 0.32, 0.64 mg·mL-1) were determined during 18 days of refrigerated storage (4 ± 1 °C). Results showed that LBG-SA coatings containing 0.32 mg·mL-1 daphnetin emulsions could significantly lower the total viable count (TVC), psychrophiles, Pseudomonas spp. and H2S-producing bacteria counts, and inhibit the productions of off-flavor compounds including the total volatile basic nitrogen (TVB-N), trimethylamine (TMA) and ATP-related compounds. 32 volatile compounds were identified by solid phase microextraction combined with gas chromatography-mass spectrometer method (SPME-GC/MS) during refrigerated storage and the treated turbot samples significantly lowered the relative content of fishy flavor compounds. Further, the LBG-SA coatings containing daphnetin could also delay the myofibril degradation of the turbot samples. These results indicated that the LBG-SA coatings with 0.32 mg·mL-1 daphnetin were a potential alternative way to improve the quality of turbot during refrigerated storage.

Effect of estragole over the RN4220 Staphylococcus aureus strain and its toxicity in Drosophila melanogaster.

Among the bacterial resistance mechanisms, efflux pumps are responsible for expelling xenobiotics, including bacterial cell antibiotics. Given this problem, studies are investigating new alternatives for inhibiting bacterial growth or enhancing the antibiotic activity of drugs already on the market. With this in mind, this study aimed to evaluate the antibacterial activity of Estragole against the RN4220 Staphylococcus aureus strain, which carries the MsrA efflux pump, as well as Estragole's toxicity in the Drosophila melanogaster arthropod model. The broth microdilution method was used to perform the Minimum Inhibitory Concentration (MIC) tests. Estragole was used at a Sub-Inhibitory Concentration (MIC/8) in association with erythromycin and ethidium bromide to assess its combined effect. As for Estragole's toxicity evaluation over D. melanogaster, the fumigation bioassay and negative geotaxis methods were used. The results were expressed as an average of sextuplicate replicates. A Two-way ANOVA followed by Bonferroni's post hoc test was used. The present study demonstrated that Estragole did not show a direct antibacterial activity over the RN4220 S. aureus strain, since it obtained a MIC ≥1024 µg/mL. The association of estragole with erythromycin demonstrated a potentiation of the antibiotic effect, reducing the MIC from 512 to 256 µg/mL. On the other hand, when estragole was associated with ethidium bromide (EtBr), an antagonism was observed, increasing the MIC of EtBr from 32 to 50.7968 µg/mL, demonstrating that estragole did not inhibited directly the MsrA efflux pump mechanism. We conclude that estragole has no relevant direct effect over bacterial growth, however, when associated with erythromycin, this reduced its MIC, potentiating the effect of the antibiotic.

Compliance in Controlled E-cigarette Studies.

INTRODUCTION: E-cigarette studies have found that the use of a variety of flavors and customizable devices results in greater use frequency and user satisfaction. However, standardized research e-cigarettes are being developed as closed systems with limited flavor options, potentially limiting user satisfaction. In this study, we explore protocol compliance in an e-cigarette study using a standardized, assigned device with puff time and duration tracking (controlled e-cigarette) and potential limitations that controlled devices and e-liquids can introduce. METHODS: In a crossover study, 49 young adult e-cigarette users were recruited using convenience sampling and assigned a controlled e-cigarette device and flavored or unflavored e-liquids on standardized protocols. E-cigarette use frequency (number of puffs per day, collected from the device) and serum cotinine levels were obtained at each of three study visits over 3 weeks. The correlation of cotinine and e-cigarette use over the preceding week was calculated at each study visit. RESULTS: Correlation of nicotine intake, as measured by serum cotinine, and puff time, as measured by puffs count and duration from the e-cigarette device, as an indicator of study protocol compliance, substantially declined after the first week of the study and were no longer correlated in the remaining study weeks (R2 = 0.53 and p ≤ .01 in week 1, R2 < 0.5 and p > .05 for remaining weeks). CONCLUSIONS: There is an emerging need for controlled e-cigarette exposures studies, but low compliance in the use of assigned devices and e-liquids may be a limitation that needs to be mitigated in future studies. IMPLICATIONS: This study is the first to analyze compliance with instructions to use a standardized e-cigarette device with puff time and duration tracking (controlled e-cigarette) across all subjects and an assigned e-liquid flavor over a 3-week period. We find that protocol compliance, as measured by correlations between e-cigarette use measures and cotinine levels, was only achieved in the first week of the study and declined thereafter. These findings indicate that the assignment of a study device and instruction to only use the study device with assigned e-liquid flavor may not be sufficient to ensure participant compliance with the study protocol. We suggest that additional measures, including behavioral and biological markers, are needed to ensure sole use of the study e-cigarette and e-liquid and to be able to interpret results from controlled e-cigarette studies.

Effect of Raspberry Ketone on Normal, Obese and Health-Compromised Obese Mice: A Preliminary Study.

Raspberry ketone (RK)-an aromatic compound found mostly in red raspberries (Rubus idaeus) is widely used as an over the counter product for weight loss. The present study was conducted to determine adverse effects associated with RK in obese and health-compromised obese mice. Two sets of experiments were conducted on normal obese and health-compromised obese mice treated with RK for a duration of 10 days. Obese conditions were induced by feeding mice a high fat diet for 10 weeks, while the health compromised obese mouse model was developed by a single intraperitoneal injection of a nontoxic dose of lipopolysaccharide (LPS) (6 mg/kg) to obese mice. Results showed that RK (165, 330, and 500 mg/kg) under obese as well as health-compromised condition retarded the gain in body weights as compared to the control groups. RK at doses 330 and 500 mg/kg resulted in 67.6 and 50% mortality, respectively in normal obese mice and 70% mortality was observed in health-compromised obese mice treated with RK at 500 mg/kg. At higher doses deaths were observed earlier than those given lower doses of RK. Significant elevations in blood alanine transaminase (ALT) were also observed with RK treatment in obese mice. Blood glucose levels were significantly elevated in all groups of mice treated with RK. This study suggests that higher doses of RK may cause adverse effects in health compromised conditions. Under these conditions, prolonged use of RK, especially in high doses, may pose a health hazard.

Flavors Enhance Nicotine Vapor Self-administration in Male Mice.

INTRODUCTION: Although the use of combustible cigarettes has decreased in many urban regions of America, the use of electronic nicotine delivery systems (ENDS) has dramatically increased. ENDS, or electronic cigarettes (e-cigarettes), differ from combustible cigarettes given that there are no restrictions on flavorant additives in e-liquids. With 95% of ENDS users vaping flavored e-liquids, it is critical to understand how flavors alter vaping-related behaviors. We have previously shown that menthol and green apple flavors enhance nicotine reward-related behavior in a mouse model and in the present study have investigated how menthol and green apple flavors alter e-Vape self-administration behavior in male mice. METHODS: Adult C57/BL6J male mice were used in vapor-inhalation self-administration assays. Mice were assigned vaping e-liquids (6 mg/mL nicotine with or without menthol or green apple flavor) to escalate on a fixed-ratio 1 (FR1) schedule in daily 3-hour sessions to examine initiation-related behaviors. Following escalation, mice were transitioned to a FR3 and progressive ratio schedules in 3-hour sessions to examine reinforcement-related behaviors. RESULTS: Here we observed that male mice exhibited increased rates of self-administration escalation on a FR1 schedule when assigned to flavored e-liquids. Upon transition to FR3, mice continued to exhibit enhanced levels of reinforcement with flavored e-liquids. We also observed that mice self-administer zero-nicotine green apple flavored e-liquids. CONCLUSIONS: These data provide additional evidence that ENDS flavors enhance vaping-related initiation and reinforcement-related behavior and promote the need to continue investigating the role ENDS flavors play in vaping-related behaviors. IMPLICATIONS: There has been much discussion recently regarding the impact of flavors on vaping-related behavior. Our study here shows that flavors significantly enhance the acquisition and reinforcement of vaping-related behavior. This suggests that flavors in electronic nicotine delivery systems significantly increase the risk of addiction-related behaviors among users of vaping products.

In vitro and in vivo cardiac toxicity of flavored electronic nicotine delivery systems.

The usage of flavored electronic nicotine delivery systems (ENDS) is popular, specifically in the teen and young adult age-groups. The possible cardiac toxicity of the flavoring aspect of ENDS is largely unknown. Vaping, a form of electronic nicotine delivery, uses "e-liquid" to generate "e-vapor," an aerosolized mixture of nicotine and/or flavors. We report our investigation into the cardiotoxic effects of flavored e-liquids. E-vapors containing flavoring aldehydes such as vanillin and cinnamaldehyde, as indicated by mass spectrometry, were more toxic in HL-1 cardiomyocytes than fruit-flavored e-vapor. Exposure of human induced pluripotent stem cell-derived cardiomyocytes to cinnamaldehyde or vanillin-flavored e-vapor affected the beating frequency and prolonged the field potential duration of these cells more than fruit-flavored e-vapor. In addition, vanillin aldehyde-flavored e-vapor reduced the human ether-à-go-go-related gene (hERG)-encoded potassium current in transfected human embryonic kidney cells. In mice, inhalation exposure to vanillin aldehyde-flavored e-vapor for 10 wk caused increased sympathetic predominance in heart rate variability measurements. In vivo inducible ventricular tachycardia was significantly longer, and in optical mapping, the magnitude of ventricular action potential duration alternans was significantly larger in the vanillin aldehyde-flavored e-vapor-exposed mice than in controls. We conclude that the widely popular flavored ENDS are not harm free, and they have a potential for cardiac harm. More studies are needed to further assess their cardiac safety profile and long-term health effects.NEW & NOTEWORTHY The use of electronic nicotine delivery systems (ENDS) is not harm free. It is not known whether ENDS negatively affect cardiac electrophysiological function. Our study in cell lines and in mice shows that ENDS can compromise cardiac electrophysiology, leading to action potential instability and inducible ventricular arrhythmias. Further investigations are necessary to assess the long-term cardiac safety profile of ENDS products in humans and to better understand how individual components of ENDS affect cardiac toxicity.

Harsh and Sweet Sensations Predict Acute Liking of Electronic Cigarettes, but Flavor Does Not Affect Acute Nicotine Intake: A Pilot Laboratory Study in Men.

INTRODUCTION: Electronic cigarette use is increasing in popularity, and thousands of flavors are available. Adolescent vaping rates in the United States have nearly doubled in the past year. Unlike combustible tobacco, added flavors are not currently regulated for some types of electronic cigarette products. Here, we investigated the role of flavor in electronic cigarette liking and acute intake. METHODS: Men (n = 39) aged 18-45 vaped in a controlled laboratory setting after being randomized to one of four e-liquids: 6 mg nicotine/mL cherry, 18 mg/mL cherry, 6 mg/mL chocolate, or 18 mg/mL chocolate. They completed several questionnaires, and vaped ad libitum for 10 minutes. After the first puff, participants rated sensations (sweetness, bitterness, coolness, harshness/irritation) on general labeled magnitude scales (gLMS) and rated overall liking on a generalized hedonic scale. Once the 10-minute session ended, participants made another set of ratings. RESULTS: Liking was generally stable across the vaping session and liking varied substantially across the four conditions. Across all conditions, sensory ratings predicted liking: harshness/irritation was negatively associated with first puff liking, whereas perceived sweetness was positively associated with first puff liking. First puff liking associated with increased amount of e-liquid vaped, but not total nicotine intake. Participants appeared to titrate their nicotine intake regardless of assigned condition. CONCLUSION: Flavored e-liquids affect acute liking ratings, but not acute nicotine intake. IMPLICATIONS: These data suggest individuals who regularly vape may titrate their nicotine intake, regardless of flavor, and contrary to expectations, acute liking did not predict total nicotine intake. However, more-liked flavors may potentially make higher nicotine levels more tolerable by adding pleasant sensations directly, rather than by perceptual masking that reduces aversive sensations.