Effects of artificial sweeteners on the AhR- and GR-dependent CYP1A1 expression in primary human hepatocytes and human cancer cells

Assessment of Aspartame (E951) Occurrence in Selected Foods and Beverages on the German Market 2000-2022

This study examines the occurrence of the artificial sweetener aspartame (E951) in foods and beverages sampled by food control authorities in Germany between 2000 and 2022. The dataset was obtained through the Consumer Information Act. Out of 53,116 samples analyzed, aspartame was present in 7331 samples (14%), of which 5703 samples (11%) in nine major food groups were further evaluated. The results showed that aspartame was most commonly found in powdered drink bases (84%), flavored milk drinks (78%), chewing gum (77%), and diet soft drinks (72%). In the solid food groups, the highest mean aspartame content was detected in chewing gum (1543 mg/kg, n = 241), followed by sports foods (1453 mg/kg, n = 125), fiber supplements (1248 mg/kg, n = 11), powdered drink bases (1068 mg/kg, n = 162), and candies (437 mg/kg, n = 339). Liquid products generally had the highest aspartame content in diet soft drinks (91 mg/L, n = 2021), followed by regular soft drinks (59 mg/L, n = 574), flavored milk drinks (48 mg/kg, n = 207), and mixed beer drinks (24 mg/L, n = 40). These results suggest that aspartame is commonly used in some foods and beverages in Germany. The levels of aspartame found were generally within the legal limits set by the European Union. These findings provide the first comprehensive overview of aspartame in the German food market and may be particularly useful in informing the forthcoming working groups of the WHO International Agency for Research on Cancer (IARC) and the WHO/FAO Joint Expert Committee on Food Additives (JECFA), which are in the process of evaluating the human health hazards and risks associated with the consumption of aspartame.

Updated systematic assessment of human, animal and mechanistic evidence demonstrates lack of human carcinogenicity with consumption of aspartame

Aspartame has been studied extensively and evaluated for its safety in foods and beverages yet concerns for its potential carcinogenicity have persisted, driven primarily by animal studies conducted at the Ramazzini Institute (RI). To address this controversy, an updated systematic review of available human, animal, and mechanistic data was conducted leveraging critical assessment tools to consider the quality and reliability of data. The evidence base includes 12 animal studies and >40 epidemiological studies reviewed by the World Health Organization which collectively demonstrate a lack of carcinogenic effect. Assessment of >1360 mechanistic endpoints, including many guideline-based genotoxicity studies, demonstrate a lack of activity associated with endpoints grouped to key characteristics of carcinogens. Other non-specific mechanistic data (e.g., mixed findings of oxidative stress across study models, tissues, and species) do not provide evidence of a biologically plausible carcinogenic pathway associated with aspartame. Taken together, available evidence supports that aspartame consumption is not carcinogenic in humans and that the inconsistent findings of the RI studies may be explained by flaws in study design and conduct (despite additional analyses to address study limitations), as acknowledged by authoritative bodies.

Association between Consumption of Artificial Sweeteners and Breast Cancer Risk: A Systematic Review and Meta-Analysis of Observational Studies

This study intends to conduct a meta-analysis based on existing research results to further investigate their relationship between artificial sweetener exposure and breast cancer risk. An electronic database literature search was performed up to July 2022, using PubMed, Web of Science, Ovid and Scopus. The relationship between artificial sweetener exposure and breast cancer (BC) incidence was evaluated by odds ratio (OR) and 95% confidence interval (CI). Among the five studies (two case-control studies and three cohort studies) that met the inclusion criteria, 314,056 participants were recruited in the cohort study, 4,043 cancer cases and 3,910 controls were recruited in the case-control study. It was found that exposure of artificial sweeteners was not related to the risk of BC (OR = 0.98, 95% CI = [0.94-1.03]). Subgroup analysis showed that compared with the non-exposure/very-low-dose group, the exposure to low, medium and high doses of artificial sweeteners were not associated with the risk of BC, which were OR = 1.01, 95% CI = [0.95-1.07], OR = 0.98, 95% CI = [0.93-1.02], OR = 0.88, 95% CI = [0.74-1.06], respectively. This study confirmed that there was no relationship between the exposure of artificial sweeteners and the incidence of BC.

The effects of aspartame on the HTR8/SVneo extravillous trophoblast cell line

Extravillous trophoblasts (EVTs) are a key cell type involved in placentation. Aspartame is an artificial sweetener with a widespread use. In rodents, aspartame ingestion during pregnancy was found to cause a reduction in placental and fetal weights, but its effect in placentation at a cellular level has not been studied. Aspartame is completely hydrolyzed in the gastrointestinal tract into L-phenylalanine, L-aspartic acid, and methanol. We aimed to study the effects of aspartame and its metabolites on placentation related characteristics of EVTs. For this, we exposed HTR-8/SVneo cells to aspartame (0.001, 0.01, 0.1, 0.5 and 1 mM), L-phenylalanine (0.14 and 0.5 mM), L-aspartic acid (0.82, 2.8 and 10 mM) or methanol (0.14 and 0.8 mM) for 24 h. Aspartame had an anti-proliferative effect, decreased the number of metabolically active cells and glucose cellular uptake and increased the number of cells arrested in S phase. L-aspartic acid significantly reduced glucose uptake and whole-cell protein content. L-phenylalanine had an anti-proliferative effect and increased the number of metabolically active cells. Interestingly, methanol exerted very marked effects on HTR8/SVneo cells: it showed an anti-proliferative effect, decreased glucose uptake, the migratory ability and the number of cells in the G2/M phase and increased oxidative stress levels, in concentrations corresponding to the blood levels after the 99th percentile of projected daily ingestion of aspartame. Overall, our results demonstrate that aspartame and its metabolites can affect several characteristics of EVTs and support the conclusion that the effect of aspartame in the placenta should be further evaluated.

The relationship between the use of artificial sweeteners and cancer: A meta-analysis of case-control studies

Although there are reports that artificial sweeteners (AS) are safe, the relationship between artificial sweeteners and cancer remains controversial. The purpose of the study is to evaluate whether the consumption of artificial sweeteners is associated with the risk of cancers. We conducted a comprehensive search of multiple databases, including MEDLINE, EMBASE, Web of Science, and Cochrane Library. We found all the literature that studied the relationship between artificial sweeteners and cancer. Ten case-control studies were included in the meta-analysis. Our findings indicated that the consumption of artificial sweeteners was not associated with an increase in cancer when all types of cancers are analyzed comprehensively (OR 0.91, 95% CI 0.75-1.11). Interestingly, the use of artificial sweeteners is inversely related to urinary system cancer risk when analyzing women individually (OR 0.76, 95% CI 0.60-0.97). Our meta-analysis found that these is no correlation between artificial sweeteners and occurrence of cancer except urinary system cancer in women. Considering some limitations found in this study, additional data from large clinical trials are needed.

Flavoured water consumption alters pharmacokinetic parameters and increases exposure of erlotinib and gefitinib in a preclinical study using Wistar rats

Background

Erlotinib (ERL) and Gefitinib (GEF) are considered first line therapy for the management of non-small cell lung carcinoma (NSCLC). Like other tyrosine kinase inhibitors (TKIs), ERL and GEF are mainly metabolized by the cytochrome P450 (CYP450) CYP3A4 isoform and are substrates for transporter proteins with marked inter-/intra-individual pharmacokinetic (PK) variability. Therefore, ERL and GEF are candidates for drug-drug and food-drug interactions with a consequent effect on drug exposure and/or drug-related toxicities. In recent years, the consumption of flavoured water (FW) has gained in popularity. Among multiple ingredients, fruit extracts, which might constitute bioactive flavonoids, can possess an inhibitory effect on the CYP450 enzymes or transporter proteins. Therefore, in this study we investigated the effects of different types of FW on the PK parameters of ERL and GEF in Wistar rats.

Methods

ERL and GEF PK parameters in different groups of rats after four weeks consumption of different flavours of FW, namely berry, peach, lime, and pineapple, were determined from plasma drug concentrations using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

Results

Data indicated that tested FWs altered the PK parameters of both ERL and GEF differently. Lime water had the highest impact on most of ERL and GEF PK parameters, with a significant increase in C_max (95% for ERL, 58% for GEF), AUC_0-48 (111% for ERL, 203% for GEF), and AUC_0-∞ (200% for ERL, 203% for GEF), along with a significant decrease in the apparent oral clearance of both drugs (65% for ERL, 67% for GEF). The order by which FW affected the PK parameters for ERL and GEF was as follows: lime > pineapple > berry > peach.

Conclusion

The present study indicates that drinking FW could be of significance in rats receiving ERL or GEF. Our results indicate that the alteration in PKs was mostly recorded with lime, resulting in an enhanced bioavailability, and reduced apparent oral clearance of the drugs. Peach FW had a minimum effect on the PK parameters of ERL and no significant effect on GEF PKs. Accordingly, it might be of clinical importance to evaluate the PK parameters of ERL and GEF in human subjects who consume FW while receiving therapy.

Lack of potential carcinogenicity for acesulfame potassium - Systematic evaluation and integration of mechanistic data into the totality of the evidence

The safety of low- and no-calorie sweeteners remains a topic of general interest. Substantial evidence exists demonstrating a lack of carcinogenicity of the no-calorie sweetener acesulfame potassium (Ace K). The objective of this evaluation was to conduct a systematic assessment of available mechanistic data using a framework that quantitatively integrates proposed key characteristics of carcinogens (KCCs) into the totality of the evidence. Over 800 KCC-relevant endpoints from a variety of in vitro and in vivo assays were assessed for quality, relevance, and activity, and integrated to determine the overall strength of the evidence for plausibility that Ace K acts through the KCC. Overall, there was a lack of activity across the KCCs (overall integrated score <0 and no "strong" categorization for evidence of activity) in which data were identified. Together with the absence of treatment-related tumor effects in rodent bioassays, these results support the conclusion that Ace K is unlikely to induce a carcinogenic response. This assessment employed a weight of the evidence analysis that includes the consideration of factors such as reliability, strength of the model system, activity, and dose in a complex and heterogeneous dataset, and the ultimate integration of multiple data streams in the cancer hazard evaluation.

Interaction studies of sodium cyclamate with DNA revealed by spectroscopy methods

The interaction between sodium cyclamate (SC) and calf thymus DNA in simulated physiological buffer (pH 7.4) using ethidium bromide (EB) as fluorescence probe was investigated by UV-vis spectrometry (UV), fluorescence, resonance light scattering (RLS) and Fourier transform infrared (FT-IR) spectroscopy, along with DNA melting studies and cyclic voltammetric (CV) measurements. The results indicate that SC can not only bind into the minor groove of DNA, but also intercalate into the DNA Base pairs. Based on UV data, the binding constant K and binding sites n of the formed DNA/SC complex were estimated to be 2.83 × 10³ mol/L and 2.0, respectively. Fluorescence results demonstrate that the quenching of DNA/EB induced by SC can mainly be attributed to static procedure. The melting studies and CV analysis further confirm that the interaction mechanism between the SC and DNA is similar to that of DNA intercalator.The results of FT-IR spectra show that a specific interaction mainly exist between SC and adenine and guanine bases of DNA, which resulting in potential damage due to some change in the information structure. The DNA saturation binding value estimated to be 1.67 based on the RLS data also indicated that SC may cause damage of DNA.

Effects of Flavored Nonalcoholic Beverages on Transcriptional Activities of Nuclear and Steroid Hormone Receptors: Proof of Concept for Novel Reporter Cell Line PAZ-PPARg

We developed and characterized a novel human luciferase reporter cell line for the assessment of peroxisome proliferator-activated receptor γ (PPARγ) transcriptional activity, PAZ-PPARg. The luciferase activity induced by PPARγ endogenous agonist 15d-PGJ2 and prostaglandin PGD2 reached mean values of (87.9 ± 14.0)-fold and (89.6 ± 19.7)-fold after 24 h of exposure to 40 μM 15d-PGJ2 and 70 μM PGD2, respectively. A concentration-dependent inhibition of 15d-PGJ2- and PGD2-induced luciferase activity was observed after the application of T0070907, a selective antagonist of PPARγ, which confirms the specificity of response to both agonists. The PAZ-PPARg cell line, along with the reporter cell lines for the assessment of transcriptional activities of thyroid receptor (TR), vitamin D3 receptor (VDR), androgen receptor (AR), and glucocorticoid receptor (GR), were used for the screening of 27 commonly marketed flavored nonalcoholic beverages for their possible disrupting effects. Our findings indicate that some of the examined beverages have the potential to modulate the transcriptional activities of PPARγ, VDR, and AR.

Investigation of the Regulatory Effects of Saccharin on Cytochrome P450s in Male ICR Mice

Saccharin, the first artificial sweetener, was discovered in 1879 that do not have any calories and is approximately 200~700 times sweeter than sugar. Saccharin was the most common domestically produced sweetener in Korea in 2010, and it has been used as an alternative to sugar in many products. The interaction between artificial sweeteners and drugs may affect the drug metabolism in patients with diabetes, cancer, and liver damage, this interaction has not been clarified thus far. Here, we examined the effects of the potential saccharin-drug interaction on the activities of 5 cytochrome P450 (CYPs) in male ICR mice; further, we examined the effects of saccharin (4,000 mg/kg) on the pharmacokinetics of bupropion after pretreatment of mice with saccharin for 7 days and after concomitant administration of bupropion and saccharin. Our results showed saccharin did not have a significant effect on the 5 CYPs in the S9 fractions obtained from the liver of mice. In addition, we observed no differences in the pharmacokinetic parameters of bupropion between the control group and the groups pretreated with saccharin and that receiving concomitant administration of saccharin. Thus, our results showed that saccharin is safe and the risk of saccharin-drug interaction is very low.

Systematic review of the relationship between artificial sweetener consumption and cancer in humans: analysis of 599,741 participants

BACKGROUND

The effect of artificial sweetener consumption on cancer risk has been debated in animal models for over four decades. To further investigate this relationship, this study aims to synthesise results from several of the most recent studies in humans.

METHODS

An online literature search was performed in MEDLINE from 2003 to 2014 using Ovid, PubMed, Web of Science, and Scopus using keywords 'artificial', 'sweetener' and 'cancer'. Ninety-two results were then manually assessed for eligibility. Studies were included if the relationship between artificial sweeteners and cancer was their central hypothesis, and if they adjusted for age, gender, smoking status and body mass index. Extracted data included study design, patient characteristics, outcome measure and results.

RESULTS

In the five publications that satisfied the inclusion criteria, significant direct associations with artificial consumption were found for laryngeal (odds ratio, OR 2.34, 95% CI: 1.20-4.55), urinary tract tumours (OR 2.12, 95% CI: 1.22-3.89), non-Hodgkin lymphoma in men (RR 1.31, 95% CI: 1.01-1.72), multiple myeloma in men (RR 2.02, 95% CI: 1.20-3.40) and leukaemia (RR 1.42, 95% CI: 1.00-2.02). Inverse relationships were found in breast (OR 0.70, 95% CI: 0.54-0.91, p trend = 0.015) and ovarian (OR 0.56, 95% CI: 0.38-0.81, p trend < 0.001) cancers.

CONCLUSION

The statistical value of this review is limited by the heterogeneity and observational designs of the included studies. Although there is limited evidence to suggest that heavy consumption may increase the risk of certain cancers, overall the data presented are inconclusive as to any relationship between artificial sweeteners and cancer.

Profiling of enantiopure drugs towards aryl hydrocarbon (AhR), glucocorticoid (GR) and pregnane X (PXR) receptors in human reporter cell lines

In the past decade, a large number of enantiopure drugs were introduced to clinical practice, since improved therapeutic effects were demonstrated for one of the enantiomers from originally racemic drug. While the therapeutic effects and safety of enantiopure drugs were tested prior to their approval, various biological enantiospecific activities of these, often "old" drugs, remain to be elucidated. In the current paper, we examined enantiospecific effects of clinically used enantiopure drugs containing one chiral center in the structure (i.e. zopiclone, tamsulosin, tolterodine, modafinil, citalopram) towards aryl hydrocarbon (AhR), glucocorticoid (GR) and pregnane X (PXR) receptors in human reporter cell lines. The cytotoxicity (IC50), agonist (EC50) and antagonist effects (IC50) of R-form, S-form and racemic mixture for each tested drugs were determined and compared in AhR-, GR- and PXR-gene reporter cell lines. Since AhR, GR and PXR are key regulators of drug metabolism, energy metabolism, immunity and play many other physiological functions, the data presented here might be of toxicological significance.