Pathologists' perspective on the study design, analysis, and interpretation of proliferative lesions in a lifetime rodent carcinogenicity bioassay of sucralose.

Sucralose, a sugar substitute first approved for use in 1991, is a non-caloric sweetener regulated globally as a food additive. Based on numerous experimental animal studies (dating to the 1980s) and human epidemiology studies, international health agencies have determined that sucralose is safe when consumed as intended. A single lifetime rodent carcinogenicity bioassay conducted by the Ramazzini Institute (RI) reported that mice fed diets containing sucralose develop hematopoietic neoplasia, but controversy continues regarding the validity and relevance of these data for predicting health effects in humans. The present paper addresses the controversy by providing the perspective of experienced pathologists on sucralose-related animal toxicity and carcinogenicity data generally, and the RI carcinogenicity bioassay findings specifically, using results from publicly available papers and international regulatory authority decisions. In the authors' view, flaws in the design, methodology, data evaluation, and reporting of the RI carcinogenicity bioassay for sucralose diminish the value of the data as evidence that this agent represents a carcinogenic hazard to humans. This limitation will remain until the RI bioassay is repeated under Good Laboratory Practices and the design, data, and accuracy of the pathology diagnoses and interpretations are reviewed by qualified pathologists with experience in evaluating potential chemically-induced carcinogenic hazards.

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.

The Neonicotinoid Imidacloprid Impairs Learning, Locomotor Activity Levels, and Sucrose Solution Consumption in Bumblebees (Bombus terrestris).

Bumblebees carry out the complex task of foraging to provide for their colonies. They also conduct pollination, an ecosystem service of high importance to both wild plants and entomophilous crops. Insecticides can alter different aspects of bumblebee foraging behavior, including the motivation to leave the hive, finding the right flowers, handling flowers, and the ability to return to the colony. In the present study, we assessed how the neonicotinoid imidacloprid affects bumblebees' foraging behavior after exposure to four different treatment levels, including field-realistic concentrations (0 [control], 1, 10, and 100 µg/L), through sucrose solution over 9 days. We observed the behavior of several free-flying bumblebees simultaneously foraging on artificial flowers in a flight arena to register the bees' complex behavior postexposure. To conduct a detailed assessment of how insecticides affect bumblebee locomotor behavior, we used video cameras and analyzed the recordings using computer vision. We found that imidacloprid impaired learning and locomotor activity level when the bumblebees foraged on artificial flowers. We also found that imidacloprid exposure reduced sucrose solution intake and storage. By using automated analyses of video recordings of bumblebee behavior, we identified sublethal effects of imidacloprid exposure at field-realistic doses. Specifically, we observed negative impacts on consumption of sucrose solution as well as on learning and locomotor activity level. Our results highlight the need for more multimodal approaches when assessing the sublethal effects of insecticides and plant protection products in general. Environ Toxicol Chem 2023;42:1337-1345. © 2023 SETAC.

Phytochemical­rich herbal formula ATG­125 protects against sucrose­induced gastrocnemius muscle atrophy by rescuing Akt signaling and improving mitochondrial dysfunction in young adult mice.

The antioxidant capability of herbal remedies has attracted widespread attention, but their molecular mechanisms in a muscle atrophy model have not been explored. The aim of the present study was to compare the bioactivity of sucrose challenged mice following treatment with ATG­125. Here, through a combination of transcriptomic and biomedical analysis, herbal formula ATG­125, a phytochemical­rich formula, was identified as a protective factor against muscle atrophy in sucrose challenged mice. Gene ontology (GO) identified differentially expressed genes that were primarily enriched in the 'negative regulation of proteolysis', 'cellular amino acid metabolic process', 'lipoprotein particle' and 'cell cycle', all of which were associated with the ATG­125­mediated prevention of muscle atrophy, particularly with regard to mitochondrial biogenesis. In skeletal muscle, a set of mitochondrial­related genes, including angiopoietin­like 4, nicotinamide riboside kinase 2 (Nmrk2), pyruvate dehydrogenase lipoamide kinase isozyme 4, Asc­type amino acid transporter 1 and mitochondrial uncoupling protein 3 (Ucp3) were markedly upregulated following ATG­125 intervention. An increase in Nmrk2 and Ucp3 expression were noted after ATG­125 treatment, in parallel with upregulation of the 'nicotinate and nicotinamide metabolism' pathway, as determined using the Kyoto Encyclopedia of Genes and Genomes (KEGG). Furthermore, KEGG pathway analysis revealed the downregulation of 'complement and coagulation cascades', 'cholesterol metabolism', 'biosynthesis of amino acids' and 'PPAR signaling pathway', which were associated with the downregulation of serine (or cysteine) peptidase inhibitor clade A member (Serpina)3, Serpina1b, Serpina1d, Serpina1e, apolipoprotein (Apo)a1 and Apoa2, all of which were cardiovascular and diabetes­associated risk factors and were regulated by ATG­125. In addition, ATG­125 treatment resulted in downregulated mRNA expression levels of ATPase sarcoplasmic/endoplasmic reticulum Ca2+ transporting 2, troponin­I1, troponin­C1 and troponin­T1 in young adult gastrocnemius muscle compared with the sucrose group. Nuclear factor­κB­hypoxia inducible factor­1α­TGFß receptor type­II­vascular endothelial growth factor staining indicated that ATG­125 decreased sucrose­induced chronic inflammation. ATG­125 was sufficient to prevent muscle atrophy, and this protective effect may be mediated through upregulation of AKT phosphorylation, upregulating the insulin growth factor­1R­insulin receptor substrate­PI3K­AKT pathway, which in turn resulted in a forkhead box O­dependent decrease in protein degradation pathways, including regulation of atrogin1 and E3 ubiquitin­protein ligase TRIM63. Peroxisome­proliferator activated receptor γ coactivator 1α (PGC1α) was decreased in young adult mice challenged with sucrose. ATG­125 treatment significantly increased PGC1α and significantly increased UCP­1,2,3 expression levels, which suggested ATG­125 poised the mitochondria for uncoupling of respiration. This effect is consistent with the increased SIRT1 levels and may explain an increase in mitochondria biogenesis. Taken together, the present study showed that ATG­125, as an integrator of protein synthesis and degradative pathways, prevented muscle wasting.

Sex-specific effects of neonatal oral sucrose treatment on growth and liver choline and glucocorticoid metabolism in adulthood.

Hospitalized preterm infants experience painful medical procedures. Oral sucrose is the nonpharmacological standard of care for minor procedural pain relief. Infants are treated with numerous doses of sucrose, raising concerns about potential long-term effects. The objective of this study was to determine the long-term effects of neonatal oral sucrose treatment on growth and liver metabolism in a mouse model. Neonatal female and male mice were randomly assigned to one of two oral treatments (n = 7-10 mice/group/sex): sterile water or sucrose. Pups were treated 10 times/day for the first 6 days of life with 0.2 mg/g body wt of respective treatments (24% solution; 1-4 µL/dose) to mimic what is given to preterm infants. Mice were weaned at age 3 wk onto a control diet and fed until age 16 wk. Sucrose-treated female and male mice gained less weight during the treatment period and were smaller at weaning than water-treated mice (P ≤ 0.05); no effect of sucrose treatment on body weight was observed at adulthood. However, adult sucrose-treated female mice had smaller tibias and lower serum insulin-like growth factor-1 than adult water-treated female mice (P ≤ 0.05); these effects were not observed in males. Lower liver S-adenosylmethionine, phosphocholine, and glycerophosphocholine were observed in adult sucrose-treated compared with water-treated female and male mice (P ≤ 0.05). Sucrose-treated female, but not male, mice had lower liver free choline and higher liver betaine compared with water-treated female mice (P < 0.01). Our findings suggest that repeated neonatal sucrose treatment has long-term sex-specific effects on growth and liver methionine and choline metabolism.

Quantification and cytotoxicity of degradation products (chloropropanols) in sucralose containing e-liquids with propylene glycol and glycerol as base.

Electronic cigarettes (e-cigarettes) have gained increasing popularity in recent years, mostly because they are supposed to be less harmful than regular cigarettes. Therefore, it is highly imperative to investigate possible noxious effects to protect the consumers. E-liquids consist of propylene glycol, glycerol, aroma compounds and sweeteners. One of these sweeteners is a chlorinated version of sucrose, namely sucralose. The aim of this work was to investigate degradation products of sucralose in the presence of propylene glycol and glycerol at different temperatures of commercially available e-cigarettes. Chemical analysis and biological tests were simultaneously performed on e-liquid aerosol condensates. The results of the chemical analysis, which was executed by employing GC-MS/GC-FID, demonstrated high amounts of various chloropropanols. The most abundant one is extremely toxic, namely 3-chloropropane-1,2-diol, which can be detected at concentrations ranging up to 10,000 mg/kg. Furthermore, a cytotoxicity investigation of the condensates was performed on HUVEC/Tert2 cells in which metabolic activity was determined by means of resazurin assay. The cellular metabolic activity significantly decreased by treatment with e-liquid aerosol condensate. Due to the results of this study, we advise against the use of sucralose as sweetener in e-liquids.

Impact of controlled high-sucrose and high-fat diets on eosinophil recruitment and cytokine content in allergen-challenged mice.

Despite an ongoing focus on the role of diet in health and disease, we have only a limited understanding of these concepts at the cellular and molecular levels. While obesity has been clearly recognized as contributing to metabolic syndrome and the pathogenesis of adult asthma, recent evidence has linked high sugar intake alone to an increased risk of developing asthma in childhood. In this study, we examined the impact of diet in a mouse model of allergic airways inflammation with a specific focus on eosinophils. As anticipated, male C57BL/6 mice gained weight on a high-calorie, high-fat diet. However, mice also gained weight on an isocaloric high-sucrose diet. Elevated levels of leptin were detected in the serum and airways of mice maintained on the high-fat, but not the high-sucrose diets. We found that diet alone had no impact on eosinophil numbers in the airways at baseline or their recruitment in response to allergen (Alternaria alternata) challenge in either wild-type or leptin-deficient ob/ob mice. However, both bronchoalveolar lavage fluid and eosinophils isolated from lung tissue of allergen-challenged mice exhibited profound diet-dependent differences in cytokine content. Similarly, while all wild-type mice responded to allergen challenge with significant increases in methacholine-dependent total airway resistance (Rrs), airway resistance in mice maintained on the isocaloric high-sucrose (but not the high-calorie/high-fat) diet significantly exceeded that of mice maintained on the basic diet. In summary, our findings revealed that mice maintained on an isocaloric high-sucrose diet responded to allergen challenge with significant changes in both BAL and eosinophil cytokine content together with significant increases in Rrs. These results provide a model for further exploration of the unique risks associated with a high-sugar diet and its impact on allergen-associated respiratory dysfunction.

Artificial sweeteners impair endothelial vascular reactivity: Preliminary results in rodents.

BACKGROUND AND AIMS: Prospective epidemiological studies highlighted recently the link between artificial sweeteners (AS) consumption and the risk of developing cardiometabolic diseases. However, underlying mechanisms remain unknown. Thus, the aim of this preliminary study was to characterize, in a healthy rat population, the effect of chronic AS consumption on body composition and vascular function, an early marker for cardiovascular disease. METHODS AND RESULTS: Healthy Wistar rats followed a 10-week standard diet including the consumption of water sweetened or not with a sucralose/acesulfame potassium solution at different concentrations: for moderate consumption at 1 and 2 mg.kg-1.day-1, respectively or high intake at 15 and 15 mg.kg-1.day-1 for both molecules (acceptable daily intake). Body fat composition has been evaluated and ex vivo aortic vasomotor function has been investigated with a pharmacological approach. CONCLUSION: Both groups of AS-treated rats showed a significant increase in subcutaneous and perirenal adipose tissue mass storage, without changes in total body mass. However, rats that have consumed AS at Acceptable Daily Intake (ADI) concentration revealed a significant vascular endothelial dysfunction compared to other groups. These results are interesting because they will help to better explain the observed increase in cardiometabolic risk.

Heating of food containing sucralose might result in the generation of potentially toxic chlorinated compounds.

Sucralose is widely used as non-caloric intense artificial sweetener. It was previously considered to be thermally stable and safe. This was based on studies performed in the early 1990s. However, significant concerns have been raised more recently regarding the physicochemical stability of sucralose at high temperatures in the context of food processing. Over the last decades different independently performed studies indicated that sucralose is decomposed at high temperatures, e.g. through cooking. This - in turn - was considered to be associated with the formation of chlorinated potentially toxic compounds, such as chloropropanols and dioxins. In this review, the literature on thermal stability of sucralose and the generation of potentially toxic compounds was assessed and comparatively discussed. Considering the validity of published data, we conclude that sucralose can be degraded at high temperatures, e.g. during cooking or baking of sucralose-containing foods. As a consequence potentially toxic chlorinated compounds might be generated.

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

Sucralose is widely used as a sugar substitute. Many studies and authoritative reviews have concluded that sucralose is non-carcinogenic, based primarily on animal cancer bioassays and genotoxicity data. To add to the body of knowledge on the potential carcinogenicity of sucralose, a systematic assessment of mechanistic data was conducted. This entailed using a framework developed for the quantitative integration of data related to the proposed key characteristics of carcinogens (KCCs). Data from peer-reviewed literature and the ToxCast/Tox21 database were evaluated using an algorithm that weights data for quality and relevance. The resulting integration demonstrated an overall lack of activity for sucralose across the KCCs, with no "strong" activity observed for any KCC. Almost all data collected demonstrated inactivity, including those conducted in human models. The overall lack of activity in mechanistic data is consistent with findings from animal cancer bioassays. The few instances of activity across the KCC were generally accompanied by limitations in study design in the context of either quality and/or dose and model relevance, highlighted upon integration of the totality of the evidence. The findings from this comprehensive and integrative evaluation of mechanistic data support prior conclusions that sucralose is unlikely to be carcinogenic in humans.

The Buckwheat Iminosugar d-Fagomine Attenuates Sucrose-Induced Steatosis and Hypertension in Rats.

SCOPE: This study examines the long-term functional effects of d-fagomine on sucrose-induced factors of metabolic dysfunctions and explores possible molecular mechanisms behind its action. METHODS AND RESULTS: Wistar Kyoto rats are fed a 35% sucrose solution with d-fagomine (or not, for comparison) or mineral water (controls) for 24 weeks. The following are recorded: body weight; energy intake; glucose tolerance; plasma leptin concentration and lipid profile; populations of Bacteroidetes, Firmicutes, bacteroidales, clostridiales, enterobacteriales, and Escherichia coli in feces; blood pressure; urine uric acid and F2t isoprostanes (F2 -IsoPs); perigonadal fat deposition; and hepatic histology and diacylglycerols (DAGs) in liver and adipose tissue. d-Fagomine reduces sucrose-induced hypertension, urine uric acid and F2 -IsoPs (markers of oxidative stress), steatosis, and liver DAGs, without significantly affecting perigonadal fat deposition, and impaired glucose tolerance. It also promotes excretion of enterobacteriales generated by the dietary intervention. CONCLUSION: d-fagomine counteracts sucrose-induced steatosis and hypertension, presumably by reducing the postprandial levels of fructose in the liver.

Hydrophobic H-bond pairing: A novel approach to improve membrane permeability.

The aim of the present study was to develop hydrophobic H-bond pairs (HHPs) of leuprolide (LEU) with non-ionic surfactants to improve its membrane permeability. LEU was lipidized via hydrophobic H-bond pairing (HHP) with the sucrose esters (SEs) sucrose laurate HLB 15 (SLA-15), sucrose palmitate HLB 16 (SPA-16), sucrose stearate HLB 11 (SST-11) and sucrose stearate HLB 15 (SST-15). HHPs were evaluated regarding precipitation efficiency in water, zeta potential, log Pn-octanol/water and dissociation behavior at various pH over time. Cytotoxic potential of HHPs of LEU with SST-11 was investigated on Caco-2 cells. Subsequently, ex vivo permeation studies were carried out across freshly excised Sprague-Dawley rat intestinal mucosa. At a molar ratio of LEU to SEs of 1:≥1 a precipitation efficiency of above 50% was achieved. Zeta potential of complexes was neither influenced by the type nor the amount of added surfactants. Log Pn-octanol/water of LEU was up to 250-fold increased due to HHP utilizing SST-11. Dissociation studies showed that HHPs of LEU with SST-11 dissociate up to 20% in gastrointestinal (GI) pH conditions within 4 h. Moreover, HHPs of LEU with SST-11 exhibited no cytotoxicity. Ex vivo permeation studies revealed 2-fold improved membrane permeation of HHPs of LEU with SST-11 compared to free LEU. Findings of this study show that HHP can be considered as a promising strategy to improve membrane permeation.

Cd36 gene expression in adipose and hepatic tissue mediates the lipids accumulation in liver of obese rats with sucrose-induced hepatic steatosis.

Obesity is considered a global epidemic and is mainly associated with the development of diabetes, cardiovascular diseases and Non-Alcoholic Fatty Liver (NAFLD). The pathogenesis between obesity and hepatic steatosis is partially known, but could involve differentiated or tissue-specific participation of the expression of Cd36 mRNA that codes for a receptor which is a transporter of free fatty acids (FFA) in different tissues, favoring the lipids storage. This relative expression was evaluated in adipose and liver tissue in rats with steatosis after consumption of sucrose for 30 and 40 weeks. Ten Wistar rats were divided into two experimental groups (St-30 and St-40), which received a standard diet plus 30 % sucrose in their water intake. These rats showed a significant increase in abdominal fat, serum biochemical determinations, HOMA-IR; as well as, changes in adipocytes size and mild portal hepatitis and grade 2 hepatic steatosis. The relative expression of Cd36 mRNA increased in liver tissue after 30 (4.5-fold) and 40 (8.5-fold) weeks of sucrose ingestión but no in adipose tissue; with respect to control group (P < 0.05). This expression was associated with a significant increase in the levles of sCD36 in serum, which is indicator of the presence of the FFA transporter in the hepatocyte membrane causing lipids accumulation. The above shows the link between the adipose and hepatic tissue for the accumulation of steatotic fat in the liver through time, mediated by the relative expression of cd36 mRNA that encodes for the FFA transporter.

Alterations to DNA, apoptosis and oxidative damage induced by sucralose in blood cells of Cyprinus carpio.

Sucralose (SUC) is an organochlorine that is used as a common sweetener in different dietary products around the world. Its extended use and production have led to this product is released into the environment in concentrations ranging from ng L-1 to µg L-1 in surface waters, groundwaters, wastewater treatment plants and ocean waters. A previous study carried out by our research team demonstrated that SUC is capable of inducing oxidative stress in Cyprinus carpio at environmentally-relevant concentrations. The aim of this study was to evaluate if SUC was capable of inducing alterations to DNA, apoptosis, and oxidative damage in the blood cells of C. carpio. Carps were exposed to two environmentally-relevant concentrations (0.05 and 155 µg L-1) of SUC, and the following biomarkers were determined: comet assay, micronucleus test (MN), caspase-3 activity, TUNEL assay, hydroperoxide content, lipid peroxidation level, protein carbonyl content and superoxide dismutase and catalase activities. Results obtained showed that SUC is capable of inducing DNA damage. A maximum increase of 35% and 23% were observed for c1 and c2, respectively in the comet assay; increases of 586% and 507.7% for c1 and c2, respectively, were found at 72 h through the MN test. The activity of caspase-3 showed a greater response for c1 and c2 at 96 h, with 271% and 493.5%, respectively. TUNEL assay also showed the highest response at 96 h, with 51.8 for c1 and 72.9 for c2; c1 y c2 were able to induce oxidative stress with the highest expression at 72 h. A correlation between DNA damage biomarkers, apoptosis and plasma levels of SUC in both concentrations were observed. With the data obtained, we can conclude that SUC, at environmentally-relevant concentrations, was capable of generating DNA alterations, apoptosis and oxidative stress in blood cells in common carp.

Hypertonic saline solution (NaCl 7.2%) enhances renal excretion of acids in cattle with acute ruminal lactic acidosis.

The present study aimed to evaluate the efficiency of hypertonic saline solution (HSS) as a novel treatment of acute ruminal lactic acidosis (ARLA) in cattle, focusing on urinary excretion of acids. Twelve cannulated steers were submitted to experimentally induced ARLA by adminis- tering sucrose into the rumen. Twenty hours later, the cattle were randomly divided into two equal groups. The first group was treated with 7.5% HSS (5 mL/kg) over 15 min, and isotonic saline solution (ISS; 20 mL/kg) for the subsequent 165 minutes. The control group was administered ISS instead of HSS. Rumen and urine samples were collected at different times during the experiment from the baseline to 64 h post-induction. The induction caused a medium-to-moderate ruminal acidosis, and a moderate degree of systemic acidosis and dehydration. Steers treated with HSS increased by 50% its glomerular filtration rate (1.61 mL/min) compared to ISS group (1.06 mL/ min; p⟨0.03). The overall volume of urine excreted by HSS group was higher than that in ISS group (1.62 L vs 0.7 L; p⟨0.02). This increase in total volume of urine provided by HSS favored a greater excretion of H+ ions in urine, which was 3.39-fold higher in HSS group (64.3*10-7 vs 18.9*10-7 Mol) as well as lactate (241.7 vs 181.8 mMol) and P urinary excretion (3.8 vs 1.1 mMol) that reduced the urine pH (5.3 vs 5.7). Only the HSS group decreased significantly blood total lactic acid concentration (20.3 %) throughout the treatment. A positive relationship was found between the excretion of urinary phosphorus and urinary pH (r2=0.562). The results showed that this novel treatment with HSS enhanced renal excretion of acids and may be recommended as an additional treatment for cattle with lactic acidosis.

A histological assessment of effects of sucralose on liver of albino rats.

OBJECTIVE OF THE STUDY: Sucralose is an artificial sweetener freely available under different brand names over the counter. This study is aimed at evaluating the histopathological changes in the liver after administration of sub lethal dose of pure sucralose. MATERIALS AND METHODS: Inbred adult Wistar albino rats weighing about 150-200g of either sex, were divided into 6 control rats and 6 experimental rats. Experimental rats were given sucralose orally by gavage in the dose of 3g/kg/day dissolved in distilled water for 30 days whereas Control rats received equal quantity of distilled water by the same route. The animals were anesthetized with anesthetic ether and then perfused with 10% formal saline. Livers were dissected out. Pieces each having thickness 5mm were taken for paraffin sectioning. 5 micron thick sections were cut using a rotary microtome. Hundred slides were made from each liver and stained with hematoxylin and eosin, periodic acid-schiff (PAS) and Masson's trichrome stain. Slides were evaluated for histomorphological changes. RESULTS: Experimental rats showed features of patchy degeneration of hepatocytes along with Kupffer cells hyperplasia, lymphocytic infiltration, sinusoidal dilatation and fibrosis indicating a definite hepatic damage on regular ingestion of sucralose. Sinusoidal width was also found to be increased in experimental animals as compared to controls. CONCLUSION: It is suggestive that sucralose should be taken with caution to avoid hepatic damage. Effects of ingestion of sucralose on human subjects should be investigated further.

Evaluation of long-term effects of artificial sweeteners on rat brain: a biochemical, behavioral, and histological study.

The aim of the present study was to compare the effects of artificial sweeteners (aspartame, saccharin, and sucralose) on rat brain. Twenty-four adult male Sprague-Dawley rats were included in the study. The control group (n = 6) received regular tap water, whereas other groups received aspartame (3 mg/kg/day, n = 6,) or saccharin (3 mg/kg/day, n = 6) or sucralose (1.5 mg/kg/day, n = 6) in the drinking water. Following 6 weeks, the passive avoidance learning (PAL) test was performed to evaluate the neurobehavioral effects of sweeteners. The brains were assessed for lipid peroxides, neuron count, and Glial fibrillary acidic protein (GFAP) immunohistochemistry. Our results demonstrated that chronic intake of sweeteners significantly impaired PAL performance in all groups. Hippocampal CA1-CA3 areas revealed significantly lower neuronal count in aspartame and increased GFAP expression in all groups. Brain lipid peroxides were significantly higher in all groups. Our findings suggest that long-term consumption of artificial sweeteners may have harmful effects on cognition and hippocampal integrity in rats.

Successful pregnancies from vitrified embryos in the dromedary camel: Avoidance of a possible toxic effect of sucrose on embryos.

Successful embryo cryopreservation facilitates the wider application of assisted reproduction technologies and also provides a useful method for gene banking of valuable genetics. Unfortunately attempts to establish an effective cryopreservation protocol for camelid embryos have been unsuccessful. In the current study, a modified vitrification protocol with three steps was investigated, whereby embryos were exposed to solutions containing increasing amounts of glycerol and ethylene glycol for fixed time periods. Embryos were then loaded into an Open Pull Straw (OPS) and plunged directly into liquid nitrogen for storage. Three experiments were designed to investigate the effect of 1) artificial shrinkage (AS) of embryos, 2) the addition of sucrose to the vitrification solutions, and 3) the replacement of sucrose by galactose in the warming solution, on the outcome of vitrification. The results showed that neither AS of hatched embryos prior to vitrification, nor the addition of sucrose into vitrification solutions improves the outcome of vitrification, while replacement of sucrose with galactose in warming solution increases the survival and developmental rates of vitrified embryos in culture. Transfer of vitrified embryos that were warmed in galactose resulted in a pregnancy rate of 42.8% per embryo or 46.1% per recipient. Collectively, these results suggest a possible species-specific toxic effect of sucrose on camel embryos, and that avoiding its use either in vitrification or warming solution is critical for establishing an effective protocol. This study may also be applicable to the vitrification of embryos of other camelid species including alpaca and llamas.

Ecotoxicological assessments show sucralose and fluoxetine affect the aquatic plant, Lemna minor.

Pharmaceuticals and personal care products (PPCP) are prevalent in aquatic systems, yet the fate and impacts on aquatic plants needs quantification for many compounds. We measured and detected sucralose (an artificial sweetener), fluoxetine (an antidepressant), and other PPCP in the Portneuf River in Idaho, USA, where Lemna minor (an aquatic plant in the environment and used in ecotoxicology studies) naturally occurs. Sucralose was hypothesized to negatively affect photosynthesis and growth of L. minor because sucralose is a chlorinated molecule that may be toxic or unusable for plant metabolism. A priori hypotheses were not created for fluoxetine due to lack of previous studies examining its impacts on plants. We conducted laboratory ecotoxicological assessments for a large range of concentrations of sucralose and fluoxetine on L. minor physiology and photosynthetic function. Frond green leaf area, root length, growth rate, photosynthetic capacity, and plant carbon isotopic composition (discrimination relative to a standard; δ13C) were measured among treatments ranging from 0 to 15000nmol/L-sucralose and 0-323nmol/L-fluoxetine. Contrary to our predictions, sucralose significantly increased green leaf area, photosynthetic capacity, and δ 13C of L. minor at environmentally relevant concentrations. The increase of δ 13C from sucralose amendments and an isotope-mixing model indicated substantial sucralose uptake and assimilation within the plant. Unlike humans who cannot break down and utilize sucralose, we documented that L. minor-a mixotrophic plant-can use sucralose as a sugar substitute to increase its green leaf area and photosynthetic capacity. Fluoxetine significantly decreased L. minor root growth, daily growth rate, and asexual reproduction at 323nmol/L-fluoxetine; however, ambiguity remains regarding the mechanisms responsible and the applicability of these extreme concentrations unprecedented in the natural environment. To our knowledge, this was the first study to show aquatic plants can uptake and metabolize sucralose as a carbon source. This study further supports the common notion that L. minor can be useful in bioremediation of PPCP from wastewaters.

Toxicological hazard induced by sucralose to environmentally relevant concentrations in common carp (Cyprinus carpio).

Sucralose (SUC) is an artificial sweetener that is now widely used in North American and Europe; it has been detected in a wide variety of aquatic environments. It is considered safe for human consumption but its effects in the ecosystem have not yet been studied in depth, since limited ecotoxicological data are available in the peer-reviewed literature. This study aimed to evaluate potential SUC-induced toxicological hazard in the blood, brain, gill, liver and muscle of Cyprinus carpio using oxidative stress biomarkers. Carps were exposed to two different environmentally relevant concentrations (0.05 and 155µgL-1) for different exposure times (12, 24, 48, 72 and 96h). The following biomarkers were evaluated: lipid peroxidation (LPX), hydroperoxide content (HPC) and protein carbonyl content (PCC), as well as the activity of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT). SUC was determined by high pressure liquid chromatography tandem mass spectrometry techniques (HPLC)-MS/MS. Results show a statically significant increase in LPX, HPC, PCC (P<0.05) especially in gill, brain and muscle, as well as significant changes in the activity of antioxidant enzymes in gill and muscle. Furthermore, the biomarkers employed in this study are useful in the assessment of the environmental impact of this agent on aquatic species.