Assessment of artificial and natural sweeteners present in packaged non-alcoholic beverages (NABs) sold on the Singapore market.

BACKGROUND: New Nutri-Grade labelling, aimed at reducing Singaporeans' sugar consumption will be implemented for all pre-packaged non-alcoholic beverages (NABs) sold in retail outlets from end 2021 onwards. It is expected such labelling will have a major impact on sugar content of beverages, as well as the replacement of sugar with non-caloric alternatives. METHODS: This study used product label data obtained from in-store surveys to investigate sugar and sweetener composition of NABs present on the Singapore market. Using this data we calculated products prospective Nutri-Grade classification in order to compare the current market composition with relation to sugar and/or sweetener use. RESULTS: Over half of the NABs on market were sweetened with sugar (59%) and were associated with less healthy Nutri-Grades of 'C' and 'D'. The use of natural sweeteners; Stevia and Monk fruit, remains low (6%). CONCLUSION: With continuous efforts by the government in promoting public health nutrition, it is expected that there will be a greater usage of sugar substitutes among NABs in response to the upcoming implementation of Nutri-Grade and ever-fluctuating consumers' demands. The data collected in this study provide a point estimate (July-September 2020) on market composition and use of both sugar and artificial sweeteners in beverages prior to integration of the mandatory labelling requirements.

Making reliable negative predictions of human skin sensitisation using an in silico fragmentation approach.

A previously published fragmentation method for making reliable negative in silico predictions has been applied to the problem of predicting skin sensitisation in humans, making use of a dataset of over 2750 chemicals with publicly available skin sensitisation data from 18 in vivo assays. An assay hierarchy was designed to enable the classification of chemicals within this dataset as either sensitisers or non-sensitisers where data from more than one in vivo test was available. The negative prediction approach was validated internally, using a 5-fold cross-validation, and externally, against a proprietary dataset of approximately 1000 chemicals with in vivo reference data shared by members of the pharmaceutical, nutritional, and personal care industries. The negative predictivity for this proprietary dataset was high in all cases (>75%), and the model was also able to identify structural features that resulted in a lower accuracy or a higher uncertainty in the negative prediction, termed misclassified and unclassified features respectively. These features could serve as an aid for further expert assessment of the negative in silico prediction.

A quantitative in silico model for predicting skin sensitization using a nearest neighbours approach within expert-derived structure-activity alert spaces.

Dermal contact with chemicals may lead to an inflammatory reaction known as allergic contact dermatitis. Consequently, it is important to assess new and existing chemicals for their skin sensitizing potential and to mitigate exposure accordingly. There is an urgent need to develop quantitative non-animal methods to better predict the potency of potential sensitizers, driven largely by European Union (EU) Regulation 1223/2009, which forbids the use of animal tests for cosmetic ingredients sold in the EU. A Nearest Neighbours in silico model was developed using an in-house dataset of 1096 murine local lymph node (LLNA) studies. The EC3 value (the effective concentration of the test substance producing a threefold increase in the stimulation index compared to controls) of a given chemical was predicted using the weighted average of EC3 values of up to 10 most similar compounds within the same mechanistic space (as defined by activating the same Derek skin sensitization alert). The model was validated using previously unseen internal (n = 45) and external (n = 103) data and accuracy of predictions assessed using a threefold error, fivefold error, European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) and Globally Harmonized System of Classification and Labelling of Chemicals (GHS) classifications. In particular, the model predicts the GHS skin sensitization category of compounds well, predicting 64% of chemicals in an external test set within the correct category. Of the remaining chemicals in the previously unseen dataset, 25% were over-predicted (GHS 1A predicted: GHS 1B experimentally) and 11% were under-predicted (GHS 1B predicted: GHS 1A experimentally). Copyright © 2017 John Wiley & Sons, Ltd.

Oh So Sweet: A Comparative Investigation of Retail Market Composition of Sweetened and Flavoured Beverages in Singapore and Australia.

The consumption of sugar and non-nutritive sweeteners has been associated with poor health outcomes. The aim of this paper was to provide a comparison of the range of sweetened or flavoured beverages between two high-income countries in the Asia-Pacific region: Australia and Singapore. Following the FoodTrackTM methodology, nutrition, labelling, and price data were collected from major Australian and Singaporean supermarket chains and convenience stores. The nutrient profiles of products were tested for differences using Kruskal−Wallis and Mann−Whitney U tests. The greatest number of products collected in Australia were from the 'carbonated beverages' category (n = 215, 40%), and in Singapore the greatest number of products were from the 'tea and coffee ready-to-drink' category (n = 182, 35%). There were more calorically sweetened beverages in Singapore compared with Australia (n = 462/517 vs. n = 374/531, p < 0.001). For calorically sweetened products, the median energy of Singaporean products was significantly higher than Australian products (134 kJ vs. 120 kJ per 100 mL, p = 0.009). In Australia, 52% of sweetened or flavoured beverages displayed a front-of-pack nutrient signposting logo, compared with 34% of sweetened or flavoured beverages in Singapore. These findings also indicate that the consumption of just one serving of calorically sweetened carbonated beverages or energy drinks would exceed the WHO maximum daily free sugar recommendations.

Nutrient composition of milk and plant-based milk alternatives: A cross-sectional study of products sold in Australia and Singapore.

Dairy and non-dairy (plant-based) alternatives are promoted as an essential component of a healthy diet. The purpose of this study was to evaluate the range of dairy milks and plant-based milk alternatives in supermarkets in Australia and Singapore, and to explore nutritional differences within the category, and between countries. Product information was collected in store from packaging. Products were sorted into dairy milks and plant-based milk alternatives, and further categorised as (i) breakfast drinks (12 % of products); (ii) plain milks (62 %); or (iii) flavoured milks (26 %). The nutrient profiles of products were tested for differences using Kruskal Wallis and Mann-Whitney U tests. Flavoured products contained almost double the median sugar content of plain products (8.3 g v. 4.6 g, p = 0.005). Two-thirds of the product range were dairy milks, which contained nearly four times the median saturated fat content (1.1 g v. 0.3 v, p < 0.0001) and more than double the amount of sugar (5.1 g v. 2.6 g, p < 0.0001) of plant-based milk alternatives, but three times more protein (3.3 g v. 1.0 g, p < 0.0001). Between countries, generally, calcium contents were similar across products, likely due to fortification of plant-based milk alternatives. Compared to Singapore, dairy milk and plant-based milk alternative products sold in Australia were generally higher in energy, protein and fat, but lower in carbohydrate content. Food supply differences between Singapore and Australia may be cultural and have nutritional implications.

Consumer habits and practices for cosmetics and personal care products in Singapore: An online survey.

Understanding trends in habits and practices of cosmetics and personal care products is essential for the assessment of product exposure and simultaneously, the establishment of safe use levels for incorporated ingredients. To date, most exposure data is limited to European and USA populations, with data on Asian-specific habits and practices lacking. This data gap needs to be filled as evidence has shown that there is a large variation in product use behaviors between consumers, across and within populations. Moreover, there is a need to seek a more efficient approach of data collection. Conventional methods of collecting habits and practices data require extensive effort and are generally cost and time intensive. In this publication, we demonstrate the feasibility of employing a rapid and cost-effective online survey approach to gather habits and practices for Southeast Asia, specifically Singapore. We describe the methodology and display the type of habits and practices data that can be gathered through this approach. Although certain limitations exist, this approach can be used to effectively collect preliminary product use data across regions and different product categories.

Genetics and pharmacogenomics in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is an uncommon disease in the general population, but a disease with significant morbidity and mortality. The prevalence of heritable PAH (HPAH) remains unknown. The reason for incomplete penetrance of HPAH is not well understood. A patient's clinical response to disease-specific therapy is complex, involving the severity of the patient's disease, other comorbidities, appropriateness of the prescribed therapy, and patient compliance. Warfarin is often used as an adjuvant therapy in patients with PAH.

Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk.

Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens.

Social experience modifies pheromone expression and mating behavior in male Drosophila melanogaster.

BACKGROUND: The social life of animals depends on communication between individuals. Recent studies in Drosophila melanogaster demonstrate that various behaviors are influenced by social interactions. For example, courtship is a social interaction mediated by pheromonal signaling that occurs more frequently during certain times of the day than others. In adult flies, sex pheromones are synthesized in cells called oenocytes and displayed on the surface of the cuticle. Although the role of Drosophila pheromones in sexual behavior is well established, little is known about the timing of these signals or how their regulation is influenced by the presence of other flies. RESULTS: We report that oenocytes contain functional circadian clocks that appear to regulate the synthesis of pheromones by controlling the transcription of desaturase1 (desat1), a gene required for production of male cuticular sex pheromones. Moreover, levels of these pheromones vary throughout the day in a pattern that depends on the clock genes and most likely also depends on the circadian control of desat1 in the oenocytes. To assess group dynamics, we manipulated the genotypic composition of social groups (single versus mixed genotypes). This manipulation significantly affects clock gene transcription both in the head and oenocytes, and it also affects the pattern of pheromonal accumulation on the cuticle. Remarkably, we found that flies in mixed social groups mate more frequently than do their counterparts in uniform groups. CONCLUSIONS: These results demonstrate that social context exerts a regulatory influence on the expression of chemical signals, while modulating sexual behavior in the fruit fly.

Generalization of courtship learning in Drosophila is mediated by cis-vaccenyl acetate.

Reproductive behavior in Drosophila has both stereotyped and plastic components that are driven by age- and sex-specific chemical cues. Males who unsuccessfully court virgin females subsequently avoid females that are of the same age as the trainer. In contrast, males trained with mature mated females associate volatile appetitive and aversive pheromonal cues and learn to suppress courtship of all females. Here we show that the volatile aversive pheromone that leads to generalized learning with mated females is (Z)-11-octadecenyl acetate (cis-vaccenyl acetate, cVA). cVA is a major component of the male cuticular hydrocarbon profile, but it is not found on virgin females. During copulation, cVA is transferred to the female in ejaculate along with sperm and peptides that decrease her sexual receptivity. When males sense cVA (either synthetic or from mated female or male extracts) in the context of female pheromone, they develop a generalized suppression of courtship. The effects of cVA on initial courtship of virgin females can be blocked by expression of tetanus toxin in Or65a, but not Or67d neurons, demonstrating that the aversive effects of this pheromone are mediated by a specific class of olfactory neuron. These findings suggest that transfer of cVA to females during mating may be part of the male's strategy to suppress reproduction by competing males.

Sequential learning of pheromonal cues modulates memory consolidation in trainer-specific associative courtship conditioning.

BACKGROUND: Associative memory formation requires that animals choose predictors for experiences they need to remember. When an artificial odor is paired with an aversive experience, that odor becomes the predictor. In more natural settings, however, animals can have multiple salient experiences that need to be remembered and prioritized. The mechanisms by which animals deal with multiple experiences are incompletely understood. RESULTS: Here we show that Drosophila males can be trained to discriminate between different types of female pheromones; they suppress courtship specifically to the type of female that was associated with unsuccessful courtship. Such "trainer-specific" learning is mediated by hydrocarbon olfactory cues and modifies the male's processing of those cues. Animals that are unable to use olfactory cues can still learn by using other sensory modalities, but memory in this case is not specific to the trainer female's maturation state. Concurrent and serial presentation of different pheromones demonstrates that the ability to consolidate memory of pheromonal cues can be modified by the temporal order in which they appear. CONCLUSION: Suppression of memory by new learning demonstrates that the dynamics of memory consolidation are subject to plasticity in Drosophila. This type of metaplasticity is essential for navigation of experience-rich natural environments.

Absence of renal adverse effects from ß-myrcene dietary administration in OECD guideline-compliant subchronic toxicity study.

ß-Myrcene is a flavoring substance that occurs naturally in a large variety of foods. At the request of the European Food Safety Authority (EFSA) for additional toxicological data on ß-myrcene, groups of Sprague Dawley rats (10/sex/group) were administered diets containing 0, 700, 2100, or 4200 ppm of ß-myrcene designed to provide nominal doses of 0, 50, 150, or 300 mg/kg bw/day in a 90-day GLP-compliant study. Based on body weights, feed consumption, and substance stability data, final estimated daily intakes of ß-myrcene were calculated to be 20.4, 58.8, and 115.2 mg/kg bw for males and 24.2, 70.0, and 135.9 mg/kg bw for females. No effects on clinical observations, hematology and clinical chemistry parameters, organ weights, or macroscopic and histopathological examinations were found attributable to ingestion of ß-myrcene. The oral no-observed-adverse-effect level (NOAEL) for rats of both sexes was the highest dose tested. Based on feed consumption and test substance stability in the diet, the NOAEL was calculated to be 115 and 136 mg/kg bw/day for males and females, respectively.

Absence of adverse effects following the gavage administration of methyl propyl trisulfide to Sprague-Dawley rats for 90 days.

Methyl propyl trisulfide is a flavoring substance found in foods such as garlic and onions. At the request of the European Food Safety Authority (EFSA) for additional toxicological data on methyl propyl trisulfide, groups of Sprague-Dawley rats (10/sex/group) were gavaged with 0 (corn oil vehicle control), 0.5, 2, or 6 mg methyl propyl trisulfide/kg bw/day in a 90-day GLP-compliant study. No effects on clinical observations, hematology and clinical chemistry parameters, organ weights, or macroscopic and histopathological examinations were found attributable to ingestion of methyl propyl trisulfide. The oral no-observed-adverse-effect level (NOAEL) for rats of both sexes was the highest dose tested of 6 mg/kg bw/day.

Absence of adverse effects following administration of piperine in the diet of Sprague-Dawley rats for 90 days.

Piperine (E,E-) is a naturally occurring pungent and spicy constituent of black pepperand is also used as an added flavoring ingredient to foods and beverages. Piperine has been determined safe under conditions of intended use as a flavoring substance by regulatory and scientific expert bodies. While concurring with the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and Flavor and Extract Manufacturers Association (FEMA) Expert Panel on the safety of piperine, the European Food Safety Authority (EFSA) requested additional toxicological data. The results of a 90-day GLPcompliant dietary study, conducted in Sprague-Dawley rats at target doses of 0, 5, 15, or 50 mg/kg bw/day, to respond to this request are presented herein. No adverse effects were found attributable to ingestion of piperine. Statistically significant changes in food consumption, body weight gain, and plasma cholesterol levels were not considered adverse as discussed in this paper. Therefore, the oral no-observed-adverse-effect level (NOAEL) was determined to be the highest dose tested of 50 mg/kg bw/day. EFSA derived a lower NOAEL of 5 mg/kg bw/day based on increased plasma cholesterol levels which still affords an adequate margin of safety of over 48,000 and concluded that piperine is not of safety concern.

The genetic architecture of life span and mortality rates: gender and species differences in inbreeding load of two seed-feeding beetles.

We examine the inbreeding load for adult life span and mortality rates of two seed beetle species, Callosobruchus maculatus and Stator limbatus. Inbreeding load differs substantially between males and females in both study populations of C. maculatus--life span of inbred females was 9-13% shorter than the life span of outbred females, whereas the life span of inbred males did not differ from the life span of outbred males. The effect of inbreeding on female life span was largely due to an increase in the slope of the mortality curve. In contrast, inbreeding had only a small effect on the life span of S. limbatus--life spans of inbred beetles were approximately 5% shorter than those of outbred beetles, and there was no difference in inbreeding load between the sexes. The inbreeding load for mean life span was approximately 0.4-0.6 lethal equivalents per haploid gamete for female C. maculatus and approximately 0.2-0.3 for both males and females of S. limbatus, all within the range of estimates commonly obtained for Drosophila. However, contrary to the predictions of mutation-accumulation models, inbreeding load for loci affecting mortality rates did not increase with age in either species, despite an effect of inbreeding on the initial rate of increase in mortality. This was because mortality rates decelerated with age and converged to a mortality plateau for both outbred and inbred beetles.

EIF2AK4 Mutations in Patients Diagnosed With Pulmonary Arterial Hypertension.

BACKGROUND: Differentiating pulmonary venoocclusive disease (PVOD) and pulmonary capillary hemangiomatosis (PCH) from idiopathic pulmonary arterial hypertension (IPAH) or heritable pulmonary arterial hypertension (HPAH) is important clinically. Mutations in eukaryotic translation initiation factor 2 alpha kinase 4 (EIF2AK4) cause heritable PVOD and PCH, whereas mutations in other genes cause HPAH. The aim of this study was to describe the frequency of pathogenic EIF2AK4 mutations in patients diagnosed clinically with IPAH or HPAH. METHODS: Sanger sequencing and deletion/duplication analysis were performed to detect mutations in the bone morphogenetic protein receptor type II (BMPR2) gene in 81 patients diagnosed at 30 North American medical centers with IPAH (n = 72) or HPAH (n = 9). BMPR2 mutation-negative patients (n = 67) were sequenced for mutations in four other genes (ACVRL1, ENG, CAV1, and KCNK3) known to cause HPAH. Patients negative for mutations in all known PAH genes (n = 66) were then sequenced for mutations in EIF2AK4. We assessed the pathogenicity of EIF2AK4 mutations and reviewed clinical characteristics of patients with pathogenic EIF2AK4 mutations. RESULTS: Pathogenic BMPR2 mutations were identified in 8 of 72 (11.1%) patients with IPAH and 6 of 9 (66.7%) patients with HPAH. A novel homozygous EIF2AK4 mutation (c.257+4A>C) was identified in 1 of 9 (11.1%) patients diagnosed with HPAH. The novel EIF2AK4 mutation (c.257+4A>C) was homozygous in two sisters with severe pulmonary hypertension. None of the 72 patients with IPAH had biallelic EIF2AK4 mutations. CONCLUSIONS: Pathogenic biallelic EIF2AK4 mutations are rarely identified in patients diagnosed with HPAH. Identification of pathogenic biallelic EIF2AK4 mutations can aid clinicians in differentiating HPAH from heritable PVOD or PCH.

The scent of age.

In many species, older males are often preferred mates because they carry 'good' genes that account for their viability. How females discern a male's age is a matter of question. However, for animals that rely heavily on chemical communication there is some indication that an animal's age can be determined by its scent. To investigate whether there are changes in body odours with age, and if so their composition, mice were trained in a Y-maze to discriminate urine odours of donor mice of different ages: Adult (3-10 months old) and Aged (more than 17 months old). Trained mice could discriminate between these two age groups by odour alone. To determine the chemical basis for these discriminations, studies were performed using gas chromatography and mass spectrometry. These analyses demonstrated differences in the ratio of urinary volatiles with age. The most prominent differences involved significantly greater amounts of 2-phenylacetamide and significantly lower amounts of methylbutyric acids in Aged animals relative to Adult animals. Fractionating and manipulating the levels of these compounds in the urine demonstrated that the mice can distinguish age based on variation in amounts of these specific compounds in the combined urine.

Intraspecific variation in odor-mediated host preference of the mosquito Culex annulirostris.

The preference of two allopatric populations of Culex annulirostris mosquitoes in South Australia (SA) for guinea pigs and chickens was investigated using host-baited traps in the field and in a flight tunnel for laboratory assays. Mosquitoes from the Riverland of SA preferred guinea pigs, those from northeast SA preferred chickens. In the field, 2184 Cx. annulirostris were captured during four experiments in each region. The proportion choosing chicken was 0.5393 in northeast SA and 0.4348 in the Riverland. In the laboratory, replicate trials utilizing 15 mosquitoes at a time yielded results concordant with field assays. This study demonstrates variation in Cx. annulirostris host preference throughout this species geographic range. Semiochemical analysis of the two host species was performed on solvent extractions and volatile trapping samples from fur and feathers, respectively. This revealed differences that are likely to be the basis for host discrimination by Cx. annulirostris.

Chemical and olfactory characterization of odorous compounds and their precursors in the parotoid gland secretion of the green tree frog, Litoria caerulea.

When stressed or challenged by a predator, the Australian green tree frog, Litoria caerulea, emits a characteristic nutty odor from its parotoid glands. This study identifies the source of the odor as the cyclic amide 2-pyrrolidone (2-PyrO). In addition, we demonstrate the presence of 2-PyrO's straight chain form, gamma-aminobutyric acid or GABA, in the frog's glandular secretion and propose an odorant-precursor relationship. What role both compounds play in the frog's defensive strategy remains unknown. Prolonged exposure to the odor is shown to result in adverse effects that may be attributed to a GABAergic mechanism. It is our hypothesis, however, that the odor acts as an aposematic signal, indicating the toxicity of the frog's nonvolatile secretion.