The pharmacokinetics and metabolism of sucralose in the rabbit

Toxicological and pharmacokinetic properties of sucralose-6-acetate and its parent sucralose: in vitro screening assays

The purpose of this study was to determine the toxicological and pharmacokinetic properties of sucralose-6-acetate, a structural analog of the artificial sweetener sucralose. Sucralose-6-acetate is an intermediate and impurity in the manufacture of sucralose, and recent commercial sucralose samples were found to contain up to 0.67% sucralose-6-acetate. Studies in a rodent model found that sucralose-6-acetate is also present in fecal samples with levels up to 10% relative to sucralose which suggest that sucralose is also acetylated in the intestines. A MultiFlow® assay, a high-throughput genotoxicity screening tool, and a micronucleus (MN) test that detects cytogenetic damage both indicated that sucralose-6-acetate is genotoxic. The mechanism of action was classified as clastogenic (produces DNA strand breaks) using the MultiFlow® assay. The amount of sucralose-6-acetate in a single daily sucralose-sweetened drink might far exceed the threshold of toxicological concern for genotoxicity (TTCgenotox) of 0.15 µg/person/day. The RepliGut® System was employed to expose human intestinal epithelium to sucralose-6-acetate and sucralose, and an RNA-seq analysis was performed to determine gene expression induced by these exposures. Sucralose-6-acetate significantly increased the expression of genes associated with inflammation, oxidative stress, and cancer with greatest expression for the metallothionein 1 G gene (MT1G). Measurements of transepithelial electrical resistance (TEER) and permeability in human transverse colon epithelium indicated that sucralose-6-acetate and sucralose both impaired intestinal barrier integrity. Sucralose-6-acetate also inhibited two members of the cytochrome P450 family (CYP1A2 and CYP2C19). Overall, the toxicological and pharmacokinetic findings for sucralose-6-acetate raise significant health concerns regarding the safety and regulatory status of sucralose itself.

Safety Assessment of Monosaccharides, Disaccharides, and Related Ingredients as Used in Cosmetics

The Cosmetic Ingredient Review Expert Panel (Panel) assessed the safety of 25 monosaccharides, disaccharides, and related ingredients and concluded these are safe in the present practices of use and concentration described in the safety assessment. Many of these ingredients are common dietary sugars, dietary sugar replacements, or very closely related analogs and salts; 7 of the ingredients are listed by the Food and Drug Administration as generally recognized as safe food substances. The most commonly reported cosmetic function is as a skin-conditioning agent; other commonly reported functions are use as a humectant or as a flavoring agent. The Panel reviewed the animal and clinical data included in this assessment, acknowledged that the oral safety of many of these ingredients has been well established, and found it appropriate to extrapolate the existing information to conclude on the safety of all the monosaccharides, disaccharides, and related ingredients.

Biological fate of low-calorie sweeteners

With continued efforts to find solutions to rising rates of obesity and diabetes, there is increased interest in the potential health benefits of the use of low- and no-calorie sweeteners (LNCSs). Concerns about safety often deter the use of LNCSs as a tool in helping control caloric intake, even though the safety of LNCS use has been affirmed by regulatory agencies worldwide. In many cases, an understanding of the biological fate of the different LNSCs can help health professionals to address safety concerns. The objectives of this review are to compare the similarities and differences in the chemistry, regulatory status, and biological fate (including absorption, distribution, metabolism, and excretion) of the commonly used LNCSs: acesulfame potassium, aspartame, saccharin, stevia leaf extract (steviol glycoside), and sucralose. Understanding the biological fate of the different LNCSs is helpful in evaluating whether reports of biological effects in animal studies or in humans are indicative of possible safety concerns. Illustrations of the usefulness of this information to address questions about LNCSs include discussion of systemic exposure to LNCSs, the use of sweetener combinations, and the potential for effects of LNCSs on the gut microflora.

P, E. T, L. F, F. M, M. L, L. B, M. M, F. B. Sucralose administered in feed, beginning prenatally through lifespan, induces hematopoietic neoplasias in male swiss mice

BACKGROUND

Sucralose is an organochlorine artificial sweetener approximately 600 times sweeter than sucrose and used in over 4,500 products. Long-term carcinogenicity bioassays on rats and mice conducted on behalf of the manufacturer have failed to show the evidence of carcinogenic effects.

OBJECTIVE

The aim of this study was to evaluate the carcinogenic effect of sucralose in mice, using a sensitive experimental design.

METHODS

Five groups of male (total n = 457) and five groups female (total n = 396) Swiss mice were treated from 12 days of gestation through the lifespan with sucralose in their feed at concentrations of 0, 500, 2,000, 8,000, and 16,000 ppm.

RESULTS

We found a significant dose-related increased incidence of males bearing malignant tumors (p < 0.05) and a significant dose-related increased incidence (p < 0.01) of hematopoietic neoplasias in males, in particular at the dose levels of 2,000 ppm (p < 0.01) and 16,000 ppm (p < 0.01).

CONCLUSIONS

These findings do not support previous data that sucralose is biologically inert. More studies are necessary to show the safety of sucralose, including new and more adequate carcinogenic bioassay on rats. Considering that millions of people are likely exposed, follow-up studies are urgent.

Simultaneous gas-chromatographic urinary measurement of sugar probes to assess intestinal permeability: use of time course analysis to optimize its use to assess regional gut permeability

BACKGROUND

Measurement of intestinal permeability is important in several diseases but currently several methods are employed. We sought to: (1) develop a new GC based method to measure urinary mannitol, lactulose and sucralose to assess regional and total gut permeability; (2) analyze the kinetics of these sugars in the urine to determine which ratio is useful to represent intestinal permeability; and (3) determine whether age, gender, race and BMI impact these values.

METHODS

Subjects drank a cocktail of sucrose, lactulose, mannitol and sucralose and these sugars were measured in the urine at 5, 12 and 24h with gas chromatography.

RESULTS

Urinary mannitol exhibited significantly different kinetics than lactulose and sucralose which were similar to each other and varied little over the 24h. No permeability differences were observed for renal function, age, race, sex, or BMI.

CONCLUSIONS

Our data do not support the use of the widely used L/M ratio as an accurate estimate of intestinal permeability. Our data support the use of: the sucralose/lactulose (S/M) ratio to measure: small intestine permeability (first 5h); small and large intestine (first 12h), and total gut permeability (24h). This was also found to be true in a Parkinson's disease model.

Sucralose, a synthetic organochlorine sweetener: overview of biological issues

Sucralose is a synthetic organochlorine sweetener (OC) that is a common ingredient in the world's food supply. Sucralose interacts with chemosensors in the alimentary tract that play a role in sweet taste sensation and hormone secretion. In rats, sucralose ingestion was shown to increase the expression of the efflux transporter P-glycoprotein (P-gp) and two cytochrome P-450 (CYP) isozymes in the intestine. P-gp and CYP are key components of the presystemic detoxification system involved in first-pass drug metabolism. The effect of sucralose on first-pass drug metabolism in humans, however, has not yet been determined. In rats, sucralose alters the microbial composition in the gastrointestinal tract (GIT), with relatively greater reduction in beneficial bacteria. Although early studies asserted that sucralose passes through the GIT unchanged, subsequent analysis suggested that some of the ingested sweetener is metabolized in the GIT, as indicated by multiple peaks found in thin-layer radiochromatographic profiles of methanolic fecal extracts after oral sucralose administration. The identity and safety profile of these putative sucralose metabolites are not known at this time. Sucralose and one of its hydrolysis products were found to be mutagenic at elevated concentrations in several testing methods. Cooking with sucralose at high temperatures was reported to generate chloropropanols, a potentially toxic class of compounds. Both human and rodent studies demonstrated that sucralose may alter glucose, insulin, and glucagon-like peptide 1 (GLP-1) levels. Taken together, these findings indicate that sucralose is not a biologically inert compound.

Sucralose

Sucralose is a nonnutritive, zero-calorie artificial sweetener. It is a chlorinated sugar substitute that is about 600 times as sweet as sucrose. It is produced from sucrose when three chlorine atoms replace three hydroxyl groups. It is consumed as tablets (Blendy) by diabetic and obese patients. It is also used as an excipient in drug manufacturing. Unlike other artificial sweeteners, it is stable when heated and can, therefore, be used in baked and fried foods. The FDA approved sucralose in 1998. This review presents a comprehensive profile for sucralose including physical, analytical, and ADME profiles and methods of its synthesis. Spectral data for X-ray powder diffraction and DSC of sucralose are recorded and presented. The authors also recorded FT-IR, (1)H- and (13)C NMR, and ESI-MS spectra. Interpretation with detailed spectral assignments is provided. The analytical profile of sucralose covered the compendial methods, spectroscopic, and different chromatographic analytical techniques. The ADME profile covered all absorption, distribution, metabolism, and elimination data in addition to pharmacokinetics and pharmacological effects of sucralose. Some nutritional aspects for sucralose in obesity and diabetes are also presented. Both chemical and microbiological synthesis schemes for sucralose are reviewed and included.

Gas chromatographic method for detection of urinary sucralose: application to the assessment of intestinal permeability

We developed a capillary column gas chromatography (CCGC) method for the measurement of urinary sucralose (S) and three other sugar probes including, sucrose, lactulose (L) and mannitol (M) for use in in vivo studies of intestinal permeability. We compared the capillary method with a packed column gas chromatography (PCGC) method. We also investigated a possible role for sucralose as a probe for the measurement of whole gut permeability. Sample preparation was rapid and simple. The above four sugars were detected precisely, without interference. We measured intestinal permeability using 5- and 24-h urine collections in 14 healthy volunteers. The metabolism of sugars was evaluated by incubating the intestinal bacteria with an iso-osmolar mixture of mannitol, lactulose and sucralose at 37 degrees C for 19 h. Sugar concentrations and the pH of the mixture were monitored. The use of the CCGC method improved the detection of sucralose as compared to PCGC. The average coefficient of variation decreased from 15% to 4%. It also increased the sensitivity of detection by 200-2000-fold. The GC assay was linear between sucralose concentrations of 0.2 and 40 g/l (r=1.000). Intestinal bacteria metabolized lactulose and acidified the media but did not metabolize sucralose or mannitol. The new method for the measurement of urinary sucralose permits the simultaneous quantitation of sucrose, mannitol and lactulose, and is rapid, simple, sensitive, accurate and reproducible. Because neither S nor M is metabolized by intestinal bacteria, and because only a tiny fraction of either sugar is absorbed, this pair of sugar probes appears to be available for absorption throughout the GI tract. Thus, the 24-h urinary concentrations of S and M, or the urinary S/M ratio following an oral dose of a sugar mixture, might be good markers for whole gut permeability.

The pharmacokinetics and metabolism of sucralose in the dog

The pharmacokinetics and metabolism of sucralose were investigated in dogs following intravenous or oral administration. Oral doses of (14)C-sucralose were rapidly absorbed, although there was some variation in the extent of absorption (range 18-48% of the dose). After intravenous or oral administration, radioactivity excreted in the urine was associated mainly with unchanged sucralose. One urinary metabolite was detected after both intravenous and oral doses and was identified by mass spectrometry as a glucuronic acid conjugate of sucralose. This metabolite accounted for about 15-20% of the intravenous dose but for only about 2-8% of the oral dose.

Repeated dose study of sucralose tolerance in human subjects

Two tolerance studies were conducted in healthy human adult volunteers. The first study was an ascending dose study conducted in eight subjects, in which sucralose was administered at doses of 1, 2. 5, 5 and 10mg/kg at 48-hour intervals and followed by daily dosing at 2mg/kg for 3 days and 5mg/kg for 4 days. In the second study, subjects consumed either sucralose (n=77) or fructose (50g/day) (n=31) twice daily in single blind fashion. Sucralose dosage levels were 125mg/day for weeks 1-3, 250mg/day during weeks 4-7, and 500mg/day during weeks 8-12. No adverse experiences or clinically detectable effects were attributable to sucralose in either study. Similarly, haematology, serum biochemistry, urinalysis and EKG tracings were unaffected by sucralose administration. In the 13-week study, serial slit lamp ophthalmologic examination performed in a random subset of the study groups revealed no changes. Fasting and 2-hour post-dosing blood sucralose concentrations obtained daily during week 12 of the study revealed no rising trend for blood sucralose. Sucralose was well tolerated by human volunteers in single doses up to 10mg/kg/day and repeated doses increasing to 5mg/kg/day for 13 weeks. Based on these studies and the extensive animal safety database, there is no indication that adverse effects on human health would occur from frequent or long-term exposure to sucralose at the maximum anticipated levels of intake.