In vitro effect of low-fluoride toothpaste supplemented with sodium trimetaphosphate, xylitol, and erythritol on enamel demineralization.

OBJECTIVE: Regular use of toothpaste with fluoride (F) concentrations of ≥ 1000 ppm has been shown to contribute to reducing caries increment. However, when used by children during the period of dental development, it can lead to dental fluorosis. In this study, we aimed to evaluate the in vitro effect of a toothpaste formulation with reduced fluoride (F) concentration (200 ppm) supplemented with sodium trimetaphosphate (TMP: 0.2%), Xylitol (X:16%), and Erythritol (E: 4%) on dental enamel demineralization. METHODOLOGY: Bovine enamel blocks were selected according to initial surface hardness (SHi) and then divided into seven experimental toothpaste groups (n=12). These groups included 1) no F-TMP-X-E (Placebo); 2) 16% Xylitol and 4% Erythritol (X-E); 3) 16% Xylitol, 4% Erythritol and 0.2%TMP (X-E-TMP); 4) 200 ppm F (no X-E-TMP: (200F)); 5) 200 ppm F and 0.2% TMP (200F-TMP); 200 ppm F, 16% Xylitol, 4% Erythritol, and 0.2% TMP (200F-X-E-TMP); and 7) 1,100 ppm F (1100F). Blocks were individually treated 2×/day with slurries of toothpastes and subjected to a pH cycling regimen for five days (DES: 6 hours and RE: 18 hours). Then, the percentage of surface hardness loss (%SH), integrated loss of subsurface hardness (ΔKHN), fluoride (F), calcium (Ca), and phosphorus (P) in enamel were determined. The data were analyzed by ANOVA (1-criterion) and the Student-Newman-Keuls test (p<0.001). RESULTS: We found that the 200F-X-E-TMP treatment reduced %SH by 43% compared to the 1100F treatments (p<0.001). The ΔKHN was ~ 65% higher with 200F-X-E-TMP compared to 1100F (p<0.001). The highest concentration of F in enamel was observed on the 1100F treatment (p<0.001). The 200F-X-E-TMP treatment promote higher increase of Ca and P concentration in the enamel (p<0.001). CONCLUSION: The association of 200F-X-E-TMP led to a significant increase of the protective effect on enamel demineralization compared to the 1100F toothpaste.

Dietary Xylitol Supplement Ameliorated AD-related Neuronal Injury by Regulating Glucose Metabolism Relevant Amino Acids in Mice.

BACKGROUND: Alzheimer's disease (AD) is one of the most common irreversible degenerative diseases of the central nervous system. Recent studies have found that patients with AD generally experience abnormal glucose metabolism. Xylitol is a functional sugar alcohol, which has been reported to regulate glucose metabolism. OBJECTIVE: The present study was designed to determine whether xylitol can alleviate cognitive impairment in AD mice. METHODS: In the current research, 5% xylitol was supplemented in the diet to treat APP/PS1 transgenic AD mice for 2 months. Cognitive ability was measured by the Morris water maze, and anxiety-like behaviors were examined by open-field experiment. Hippocampal cellular apoptosis and mitochondria pathway related apoptotic proteins were tested by TUNEL staining and immunoblotting, respectively. By LC-MS, plasma levels of glucose metabolism intermediates and related amino acids were evaluated. RESULTS: Results showed that xylitol could significantly ameliorate anxiety-like activity in AD mice by partially regulating expression levels of mitochondrial pathway-related apoptotic proteins. Xylitolregulated glucose metabolism may play an important role in the process. CONCLUSION: The current study suggests that xylitol may be a potential candidate for improving neuropsychiatric behavior in AD by regulating the levels of TCA cycle intermediates and related amino acids in glucose metabolism.

Xylitol acts as an anticancer monosaccharide to induce selective cancer death via regulation of the glutathione level.

Herbal medicines and their bioactive compounds are increasingly being recognized as useful drugs for cancer treatments. The parasitic fungus Cordyceps militaris is an attractive anticancer herbal since it shows very powerful anticancer activity due to its phytocompound cordycepin. We previously discovered and reported that a high amount of xylitol is present in Cordyceps militaris extract, and that xylitol unexpectedly showed anticancer activity in a cancer-selective manner. We thus hypothesized that xylitol could become a useful supplement to help prevent various cancers, if we can clarify the specific machinery by which xylitol induces cancer cell death. It is also unclear whether xylitol acts on cancer suppression in vivo as well as in vitro. Here we show for the first time that induction of the glutathione-degrading enzyme CHAC1 is the main cause of xylitol-induced apoptotic cell death in cancer cells. The induction of CHAC1 is required for the endoplasmic reticulum (ER) stress that is triggered by xylitol in cancer cells, and is linked to a second induction of oxidative stress in the treated cells, and eventually leads to apoptotic cell death. Our in vivo approach also demonstrated that an intravenous injection of xylitol had a tumor-suppressing effect in mice, to which the xylitol-triggered ER stress also greatly contributed. We also observed that xylitol efficiently sensitized cancer cells to chemotherapeutic drugs. Based on our findings, a chemotherapeutic strategy combined with xylitol might improve the outcomes of patients facing cancer.

Remineralizing Effect of Xilitol, Juniperus Communis and Camellia Sinensis Added to a Toothpaste: An In Vitro Study / Efecto remineralizante del Xilitol, Juniperus Communis y Camellia Sinensis adicionados en pastas dentales: Estudio in vitro

ABSTRACT The aim of this study was to explore the remineralizing effect of toothpastes based on Xilitol, Camellia Sinensis and Juniperus Communis. An in vitro experimental study was carried out in an 18 human premolars sample, which were treated with one of the 3 evaluated toothpastes and a control fluoride one. The atomic percentages of Ca and P were evaluated by Energy Dispersive X-ray Spectroscopy (EDS). In addition, the enamel surface of treated teeth was visualized by Scanning Electron Microscopy (SEM). The evaluations were carried out in three stages: pre-treatment, after an artificial demineralization process and after the treatment with the toothpastes. In the statistical analysis, the one-way ANOVA and Pearson correlation tests were used. Xilitol and Juniperus Communis showed the greatest gain of P ions compared to the control group (p<0.01). As for Ca, the group treated with xylitol-based toothpaste showed more ion gain compared with the control group (p<0.01). In the Pearson correlation test between Ca and P, statistically significant correlations were observed in all groups (p<0.01), ranging between r=0.7413 (Xylitol Group) and r=0.9510 (Control Group). We concluded that Xylitol paste showed the highest remineralizing property, both in the EDS analysis and in the SEM images.

RESUMEN El objetivo de este studio fue explorer el efecto remineralizante de las cremas dentales compuestas de Xilitol, Camelia Sinensis y Juniperus Communis. Se llevó a cabo un estudio experimental in vitro en una muestra de 18 premolares humanos, los cuales fueron tratados con una de las tres pastas dentales evaluadas y una fluorada. Los porcentajes atomicos de Ca y P fueron evaluados por Espectroscopia de rayos X de energía dispersive (EDS). Además, la superficie del esmalte de los dientes tratados fue examinada por Microscopia Electronica de Barrido (SEM). Las evaluaciones fueron llevadas a cabo en tres etapas: pre-tratamiento, despues de un proceso artificial de desmineralizacion y después del tratamiento con las pastas dentales. Se usaron ANOVA de una via y correlacion de Pearson para el analisis estadistico. Xilitol y Juniperus Communis mostraron la mayor ganancia de iones P comparados con el grupo control (p<0.01), con rangos entre r=0.7413 (Grupo con Xylitol) and r=0.9510 (Group Control). Se concluyó que la pasta con Xilitol mostró las mayores propiedades remineralizantes, tanto en el analisis EDS y las imágenes SEM.

Xylitol nasal irrigation in the treatment of chronic rhinosinusitis.

OBJECTIVE: To evaluate the efficacy of xylitol nasal irrigation (XNI) treatment on chronic rhinosinusitis (CRS) and to investigate the effect of XNI on nasal nitric oxide (NO) and inducible nitric oxide synthase (iNOS) mRNA in maxillary sinus. MATERIALS AND METHODS: Patients with CRS were enrolled and symptoms were assessed by Visual Analog Scale (VAS) and Sino-Nasal Outcome Test 22 (SNOT-22). Nasal NO and iNOS mRNA in the right maxillary sinus were also examined. Then, they were treated with XNI (XNI group) or saline nasal irrigation (SNI, SNI group) for 30days, after which their symptoms were reassessed using VAS and SNOT-22, and nasal NO and iNOS mRNA in the right maxillary sinus were also reexamined. RESULTS: Twenty-five out of 30 patients completed this study. The scores of VAS and SNOT-22 were all reduced significantly after XNI treatment, but not after SNI. The concentrations of nasal NO and iNOS mRNA in the right maxillary sinus were increased significantly in XNI group. However, significant changes were not found after SNI treatment. Furthermore, there were statistical differences in the assessments of VAS and SNOT-22 and the contents of nasal NO and iNOS mRNA in the right maxillary sinus between two groups. CONCLUSIONS: XNI results in greater improvement of symptoms of CRS and greater enhancement of nasal NO and iNOS mRNA in maxillary sinus as compared to SNI.

Ameliorating Effect of Dietary Xylitol on Human Respiratory Syncytial Virus (hRSV) Infection.

Human respiratory syncytial virus (hRSV) is the most common cause of bronchiolitis and pneumonia in infants. The lack of proper prophylactics and therapeutics for controlling hRSV infection has been of great concern worldwide. Xylitol is a well-known sugar substitute and its effect against bacteria in the oral cavity is well known. However, little is known of its effect on viral infections. In this study, the effect of dietary xylitol on hRSV infection was investigated in a mouse model for the first time. Mice received xylitol for 14 d prior to virus challenge and for a further 3 d post challenge. Significantly larger reductions in lung virus titers were observed in the mice receiving xylitol than in the controls receiving phosphate-buffered saline (PBS). In addition, fewer CD3(+) and CD3(+)CD8(+) lymphocytes, whose numbers reflect inflammatory status, were recruited in the mice receiving xylitol. These results indicate that dietary xylitol can ameliorate hRSV infections and reduce inflammation-associated immune responses to hRSV infection.

Anti-irritant and anti-inflammatory effects of glycerol and xylitol in sodium lauryl sulphate-induced acute irritation.

BACKGROUND: Glycerol is known to possess anti-irritant and hydrating properties and previous studies suggested that xylitol may also have similar effects. OBJECTIVE: Our aim was to study whether different concentrations of these polyols restore skin barrier function and soothe inflammation in sodium lauryl sulphate (SLS)-induced acute irritation. METHODS: The experiments were performed on male SKH-1 hairless mice. The skin of the dorsal region was exposed to SLS (5%) for 3 h alone or together with 5% or 10% of glycerol respectively. Further two groups received xylitol solutions (8.26% and 16.52% respectively) using the same osmolarities, which were equivalent to those of the glycerol treatments. The control group was treated with purified water. Transepidermal water loss (TEWL) and skin hydration were determined. Microcirculatory parameters of inflammation were observed by means of intravital videomicroscopy (IVM). Furthermore, accumulation of neutrophil granulocytes and lymphocytes, the expression of inflammatory cytokines and SLS penetration were assessed, as well. RESULTS: Treatment with the 10% of glycerol and both concentrations of xylitol inhibited the SLS-induced elevation of TEWL and moderated the irritant-induced increase in dermal blood flow and in the number of leucocyte-endothelial interactions. All concentrations of the applied polyols improved hydration and prevented the accumulation of lymphocytes near the treatment site. At the mRNA level, neither glycerol nor xylitol influenced the expression of interleukin-1 alpha. However, expression of interleukin-1 beta was significantly decreased by the 10% glycerol treatment, while expression of tumour necrosis factor-alpha decreased upon the same treatment, as well as in response to xylitol. Higher polyol treatments decreased the SLS penetration to the deeper layers of the stratum corneum. CONCLUSION: Both of the analysed polyols exert considerable anti-irritant and anti-inflammatory properties, but the effective concentration of xylitol is lower than that of glycerol.

Xerostomía postradioterapia. Eficacia de tratamientos tópicos basados en aceite de oliva, betaína y xilitol / Xerostomia post-radiation therapy. Efficacy of topical treatments based on olive oil, betaine and xylitol

La xerostomía es la complicación más frecuente en los pacientes que reciben radioterapia para el cáncer oral. La reducción en la tasa de flujo salival y una disminución de su pH están directamente relacionado con un cambio en la composición de la saliva y el desplazamiento de la microflora oral hacia especies bacterianas cariogénicas. Por otro lado sabemos que la xerostomía se asocia a dificultad para el habla, la masticación, la deglución, cambios en el sabor, caries dentales, sensación de ardor, infecciones microbianas y un deterioro de la calidad de vida. El manejo de la xerostomía incluye la prevención, la estimulación y el tratamiento sintomático. La prevención no siempre es posible a pesar de que con radioterapia de intensidad modulada (IMRT), se puede administrar dosis más bajas de radiación a las glándulas parótidas. Los fármacos estimuladores, como los agonistas colinérgicos, han demostrado mejorar la xerostomía, sin embargo tienen efectos secundarios y están contraindicados en algunas patologías. Hoy disponemos de una gran variedad de productos tópicos para el alivio de los síntomas de la boca seca, como la goma de mascar, pastillas sin azúcar, sustitutos salivales, cremas hidratantes o pastas dentales. Un trabajo previo nos indica que el uso diario de productos de boca seca tópicos que contienen aceite de oliva, betaína y xilitol es seguro y eficaz en el alivio de los síntomas de xerostomía en pacientes con xerostomía inducida por fármacos. En este trabajo se revisa la eficacia de las diversas opciones de tratamiento para la hiposalivación inducida por la radiación y presentamos nuestros resultados con el uso de productos tópicos específicos en estos pacientes (AU)

Xerostomia is the most frequent complication among patients who receive radiotherapy for oral cancers. A reduction in salivary flow rate and decrease of its pH is paralleled with a change in saliva competence and shifting of oral microflora to cariogenic bacterial spices. Therefore difficulties in speech, mastication, swallowing, changes in taste, dental caries, burning sensation, microbial infections and a compromised quality of life are associated with the presence of xerostomia. Studies have led to three therapeutic approach for xerostomia treatment: prevention, stimulation and symptomatic treatment. Prevention it is not always possible, although intensity modulated radiation therapy (IMRT) technique, gives the ability to delivering lower doses of radiation to parotid glands. Stimulation agents as cholinergic agonist have all demonstrated some ability to improve xerostomia, however have side effects and are contraindicated for certain medical disorders. There are a huge variety of products for relief dry mouth symptoms as Chewing gum, sugarfree lozenges, salivary substitutes and moisturizers, toothpastes. A previous study report that the daily use of topical dry mouth products containing olive oil, betaine and xilitol is safe and effective in relieving symptoms of xerostomia in a population with polypharmacy-induced xerostomia. The objective of this study is to review efficacy of various treatment options for radiation-induced hyposalivation and present our results with the use of specific topical products in this patients (AU)

A randomized trial on the inhibitory effect of chewing gum containing tea polyphenol on caries.

OBJECTIVE: The purpose of the study was to determine the cariostatic potential of a chewing gum containing tea polyphenol. STUDY DESIGN: A total of 157 schoolchildren aged 8-9 years were randomly allocated into three groups. Two groups received chewing gum with or without tea polyphenol. A third group did not receive any chewing gum. A single examiner assessed the caries status for all participates at baseline, 12 months and 24 months. A one-way analysis of variance (ANOVA) was performed to evaluate differences among the groups at each interval The Chi-square test was used to compare the caries-free rate among the three groups. RESULTS: The mean DMFT increment was 0.17 for the polyphenol gum group, 0.60 for the control gum group, and 1.15 for the no gum group. Children who chewed gum containing tea polyphenol had a significantly lower mean DMFS increment over the 24-month period than did the other two groups (p < 0.05). The caries-free rate in the polyphenol gum group was significantly higher than that in the other two groups (p < 0.05) after two years. CONCLUSION: These findings indicated that the oral application of chewing gum with tea polyphenol has an inhibitory effect on dental caries.

Effect of a sugar-free chewing gum containing magnolia bark extract on different variables related to caries and gingivitis: a randomized controlled intervention trial.

The effect of magnolia bark extract (MBE) on different variables related to caries and gingivitis administered daily through a sugar-free chewing gum was evaluated. The study was performed with healthy adult volunteers at high risk for caries as a randomized double-blind interventional study. 120 subjects with a salivary mutans streptococci (MS) concentration ≥10(5) CFU/ml and presence of bleeding on probing >25% were enrolled and divided into three groups: magnolia, xylitol and control. The study design included examinations at baseline, after 7 days, after 30 days of gum use and 7 days after the end of gum use. Plaque pH was assessed using the strip method following a sucrose challenge. Area under the curve (AUC(5.7) and AUC(6.2)) was recorded. Whole saliva was collected and the number of salivary MS (CFU/ml) was counted. Bleeding on probing was recorded as a proxy of dental plaque. Data were analyzed using ANOVA repeated measures. Magnolia gum significantly reduced plaque acidogenicity, MS salivary concentration and gingival bleeding compared to xylitol and control gums. Subjects from the magnolia and xylitol groups showed both MS concentration (p = 0.01 and 0.06, respectively) and AUC(5.7) (p = 0.01 and 0.04, respectively) to be significantly lower compared to baseline. Thirty-day use of a chewing gum containing MBE showed beneficial effects on oral health, including reduction of salivary MS, plaque acidogenicity and bleeding on probing.

National survey of pediatricians' opinions about and practices for acute otitis media and xylitol use.

BACKGROUND: Acute otitis media (AOM) is the main reason for physician visits and antibiotic prescriptions in children. Pediatricians (Peds) are gatekeepers for services and sources of information for families. The 2004 American Academy of Pediatrics/American Academy of Family Physicians (AAP/AAFP) Clinical Practice Guideline: Diagnosis and Management of Acute Otitis Media recommended preventative and management measures for Peds' practice. Treatments for AOM (antimicrobial therapy and surgery) sometimes have questionable effectiveness, risks, and high costs. Thus, Peds should consider using prophylactics for AOM that are easy to administer, cost-effective, and have minimal side effects. Xylitol, a naturally occurring sugar alcohol, is widely used to prevent AOM and for other health conditions in Europe, and as a dental caries prophylaxis in the United States. It would be helpful to know Peds' attitudes and practices to identify barriers to xylitol's use as a prophylaxis for AOM in the United States. PURPOSE: To conduct a national survey of Peds in the United States to evaluate how closely they adhered to the AAP/AAFP guideline, and their knowledge and opinions about xylitol use. RESEARCH DESIGN: A randomized, national postal survey. METHOD: A 48-item questionnaire developed for this study was mailed to a random sample of 506 Peds within the United States during spring 2009. It assessed Peds' demographics, adherence to the guideline, and knowledge and opinions about and use of xylitol as a prophylaxis for AOM in children. RESULTS: The questionnaire response rate was 22% (98 useable/506 mailed - 63 returned undeliverable). Participants were about equal for gender, and almost all were in private practice for over 10 yr. Most had pediatric patients with at least one bout of AOM annually. The majority adhered to the guideline (e.g., almost all routinely assessed and managed patients' pain for AOM and encouraged prevention by recommending that families reduce risk factors). Most used and were comfortable with otoscopy for diagnosing AOM, but not tympanometry. Almost all believed that conductive hearing loss could hinder speech-language and academic development, and AOM could reduce quality of life of children. They also believed that those under 6 mo of age with AOM should receive antibacterial therapy beginning with amoxicillin but did not use complementary and alternative medicine (CAM). Only about half knew about medical uses for xylitol, but of those, most were aware of its use in chewing gum to prevent AOM but had not used it with patients. They were not sure of xylitol's effectiveness or appropriate dosages but cited stomach cramping and diarrhea as possible side effects. Most would use xylitol if evidence supported it and wanted information about it via reprints or electronically. Few agreed that audiologists are important in diagnosing/managing AOM. CONCLUSIONS: Most of these Peds adhered to the AAP/AAFP guideline. They were not using CAMs like xylitol for preventing AOM in children. Future research should focus on prevention and the use of xylitol as a possible prophylaxis regimen for AOM in patients.

Antihyperlipidemic activity of 3-hydroxymethyl xylitol, a novel antidiabetic compound isolated from Casearia esculenta (Roxb.) root, in streptozotocin-diabetic rats.

Casearia esculenta root (Roxb.) is widely used in traditional system of medicine to treat diabetes in India. An active compound, 3-hydroxymethyl xylitol (3-HMX), has been isolated, and its optimum dose has been determined in a short duration study and patented. In addition, the long-term effect of 3-HMX in type 2 diabetic rats on carbohydrate metabolism was investigated, and its antihyperglycemic effect was shown previously (Chandramohan et al., Eur J Pharmacol 2008;590:437-443). In this study we investigated the effect of 3-HMX on plasma and tissue lipid profiles in streptozotocin-induced diabetic rats. Diabetes was induced in adult male albino rats of the Wistar strain, weighing 180-200 g, by administration of streptozotocin (40 mg/kg of body weight) intraperitoneally. The normal and diabetic rats were treated with 3-HMX (40 mg/kg BW/day) for 45 days. The levels of total cholesterol, triglycerides, free fatty acids, and phospholipids were assayed in the plasma besides lipoprotein-cholesterol (high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), and very low density lipoprotein-cholesterol (VLDL-C)) and tissues (liver, kidney, heart, and brain). Total cholesterol, triglyceride, free fatty acid, and phospholipid (LDL-C and VLDL-C in plasma only) levels increased in plasma and tissues significantly, whereas plasma HDL-C significantly decreased in diabetic rats. Treatment with 3-HMX or glibenclamide reversed the above-mentioned changes and improved toward normalcy. Histological study of liver also confirmed the biochemical findings. Thus administration of 3-HMX is able to reduce hyperglycemia and hyperlipidemia related to the risk of diabetes mellitus.

Safety and effectiveness of topical dry mouth products containing olive oil, betaine, and xylitol in reducing xerostomia for polypharmacy-induced dry mouth.

Polypharmacy is a common cause of salivary hypofunction, producing symptoms of dry mouth or xerostomia, especially among older populations. As the number of older people continues to increase, polypharmacy-induced salivary hypofunction is becoming an increasing problem. Many over-the-counter products are available for relieving symptoms of dry mouth, but few have been tested in controlled clinical investigations. The purpose of this investigation was to evaluate the safety and efficacy of a group of topical dry mouth products (toothpaste, mouth rinse, mouth spray and gel) containing olive oil, betaine and xylitol. Forty adults were entered into this single-blinded, open-label, cross-over clinical study and 39 completed all the visits. Subjects were randomly assigned at baseline to using the novel topical dry mouth products daily for 1 week, or to maintain their normal dry mouth routine care. After 1 week, they were crossed over to the other dry mouth regimen. The results demonstrated that the use of the novel topical dry mouth products increased significantly unstimulated whole salivary flow rates, reduced complaints of xerostomia and improved xerostomia-associated quality of life. No clinically significant adverse events were observed. These data suggest that the daily use of topical dry mouth products containing olive oil, betaine and xylitol is safe and effective in relieving symptoms of dry mouth in a population with polypharmacy-induced xerostomia.

Oral mucous membrane flora in patients using saliva substitutes.

UNLABELLED: Salivary substitutes are sometimes valuable for elderly people and radiotherapy patients, and may be used indefinitely. It is possible that this change in the ecology may effect the oral flora. OBJECTIVE: To analyse the presence of micro-organisms on oral mucous membranes during use of saliva substitutes. DESIGN: Cross-over single-blind study. SETTING: Clinic for Maxillofacial Surgery, Malmö University Hospital and Department of Oral Microbiology, Malmö University. SUBJECTS: 19 patients with low salivary secretion who had been radiated for cancer in the head and neck region. INTERVENTION: Two saliva substitutes: linseed extract and a carboxymethyl cellulose preparation (Salinum and MAS-84) were used for 3 week periods. MEASUREMENTS: Microbial samples taken, processed and analysed. RESULTS: No differences were observed when comparing baseline values with the results after the saliva substitutes and no significant differences between the use of different agents. CONCLUSION: The study suggests that use of linseed extract and carboxymethyl cellulose preparation during periods of weeks does not influence flora commonly related to caries, periodontitis or infections in the oral mucous membranes.

Dietary xylitol protects against weakening of bone biomechanical properties in ovariectomized rats.

The effects of dietary xylitol (xyl) on bone biomechanical properties in ovariectomized rats (ovx) were studied. Forty-two 3-mo-old female Wistar rats were divided into three groups of 14. Rats in two groups were ovariectomized, while those in the control group underwent a sham operation. All rats received a basal diet, and half of the ovx were given an additional 10 g/100 g dietary xyl supplementation. Three months later the rats were killed and their tibias, femurs and humeri were prepared. The tibias were used for analyses of bone density and trabecular bone volume (BV/TV) and for the three-point bending test. The femurs were used for the torsion test and for the loading test of the femoral neck. The humeri were used for analyses of bone ash weight and bone concentrations of calcium and phosphorus. Dietary xyl gave a significant protection against ovariectomy-caused decline of tibial stress in the three-point bending test, of femoral shear stress in the torsion test, and of stress of the femoral neck, without affecting bone elasticity values. Xyl restricted the ovariectomy-caused reduction in bone density, in bone ash weight and in concentrations of bone calcium and phosphorus. Furthermore, trabecular bone loss in ovx was significantly suppressed by dietary xyl. These results indicate that a 10% dietary supplementation of xyl in ovx has a protective effect against the weakening of bone biomechanical properties. This is related to greater BV/TV and maintained bone mineral content.

Physical, chemical, and histologic changes in dentin caries lesions of primary teeth induced by regular use of polyol chewing gums.

A previous clinical trial showed that long-term use of saliva-stimulating polyol (xylitol and sorbitol) chewing gums was associated with arrest of dental caries in young subjects. After a 20-22-month intervention (when the subjects were 8 years old), a total of 23 primary teeth with extensive dentin caries lesions whose surface in clinical examination was found to be totally rehardened (remineralized) could be removed because the teeth were near their physiologic exfoliation time. These teeth were subjected to histologic, microhardness, and electron microscopic tests. The majority of the specimens had been remineralized from the surface by a non-cellular-mediated process within the remaining collapsed, organic extracellular matrix associated with the remaining dentinal surface. Many of the underlying dentinal tubules were filled with a matrix that had been subsequently mineralized. Dental microanalyses showed that the topmost (outer) 20-microm-thick rehardened layer of the lesions exhibited the highest Ca:P ratio, which leveled off at a depth of approximately 150 microm. The rehardened surface layer (normally <0.1 mm in thickness) was significantly (P < 0.001) harder than sound dentin and nearly as hard as sound enamel. Although the main source of the mineral present in the rehardened layer was most likely of salivary origin, some extracellular remineralization was probably mediated by odontoblasts. The results complete the dinical diagnoses of the original trial and suggest that regular use of polyol chewing gums may induce changes in dentin caries lesions, which in histologic and physiochemical studies show typical characteristics of rehardening and mineralization.

Dietary xylitol supplementation prevents osteoporotic changes in streptozotocin-diabetic rats.

The effects of 10% and 20% dietary xylitol supplementation on the biomechanical properties, trabeculation, and mineral content of long bones were studied in streptozotocin-diabetic rats. Forty 3-month-old male Wistar rats were divided randomly into four groups of 10. Rats in three groups were administered a single injection of streptozotocin (50 mg/kg body weight) to induce type I diabetes, while animals in the fourth group were given a sham injection of physiological saline. The sham-injected group and one of the streptozotocin-diabetic groups were fed the basal diet, while the two diabetic groups were fed the same diet supplemented with 10% and 20% xylitol (wt/wt). After 3 months, the rats were killed and the long bones were prepared for analysis. The 10% and 20% dietary xylitol supplementation significantly prevented the type I diabetes-induced decrease in the mechanical stress resistance of the tibia in the three-point bending test, the shear stress of the femur in the torsion test, and the stress resistance of the femoral neck in the loading test. No statistically significant differences were found between any groups in the values for strain or Young's modulus in the three-point bending test, or in the values for the shear modulus of elasticity in the torsion test. These findings indicate that dietary xylitol protects against the weakening of the bone strength properties of both cortical and trabecular bone without affecting the elastic-plastic properties. Supplementation with 10% and 20% dietary xylitol significantly prevented the type I diabetes-induced decrease of humeral ash weight and tibial density. Histomorphometric data for the secondary spongiosa of the proximal tibia showed that 10% and 20% dietary xylitol supplementation also significantly prevented the type I diabetes-induced loss of trabecular bone volume. In conclusion, dietary xylitol supplementation protects against the weakening of bone biomechanical properties in streptozotocin-diabetic rats. This is related to the preserved bone mineral content and preserved trabecular bone volume.

The role of ascorbic acid and xylitol in etomidate-induced adrenocortical suppression in humans.

Etomidate-induced suppression of cortisol biosynthesis is a result of a blockade of 11-beta-hydroxylation in the adrenal gland, mediated by the imidazol radical of etomidate. Since the generation of steroids requires reductive and energy rich equivalents, the present study examined whether supplementation with ascorbic acid or xylitol, a major source of NADPH, could attenuate adrenal suppression by etomidate in human subjects by promoting the turnover rate of 11-beta-hydroxylase. During continuous etomidate/alfentanil anaesthesia for pelviscopic surgery 30 female patients received either Ringer's lactate, xylitol (0.25 g kg-1 h-1) or ascorbic acid (0.5 g h-1) intravenously (i.v.). The plasma concentrations of cortisol, aldosterone and dehydroepiandrosterone (DHEA) were recorded for 5 h after end of surgery and a stimulation with synthetic ACTH was performed. The results showed no evidence of a clinically relevant attenuating effect of ascorbic acid or xylitol on etomidate-induced adrenocortical suppression. However, the observed suppression of cortisol levels was not enough to allow an attenuating affect to be measured.