Disease relevance of xylitol

• The variation in metabolism of glucose and xylitol by diverse rat hepatocellular carcinomas and partially hepatectomized rat livers was studied [1].
• In addition, a therapeutic and preventive effect for xylitol in human and animal dental caries has been demonstrated [2].
• This conclusion is supported by the facts that (a) both sorbitol and mannitol have been used as sweeteners for some time without apparent side effects, and (b) extensive long-term studies with dietary xylitol in Europe have not yielded any reports of toxicity [3].
• Although accumulation of polyols such as xylitol and sorbitol is associated with MI depletion in diabetic complications, no causal relationship has been established [4].
• Structures of D-xylose isomerase from Arthrobacter strain B3728 containing the inhibitors xylitol and D-sorbitol at 2.5 A and 2.3 A resolution, respectively [5].

Psychiatry related information on xylitol

• The long-term caries risk reduction associated with xylitol strongly depended on when teeth erupted (p < 0.02) [6].
• Case Description-8 adult dogs were evaluated for treatment of lethargy and vomiting after ingestion of xylitol, a sugar alcohol used as a sweetener in various products [7].
• When the dietary habits were not altered, neither the sucrose nor the xylitol-containing chewing gums had significant effects on the plaque scores [8].
• The strengths and limitations of the xylitol biosensor are its high affinity for NAD+, slow reaction time, narrow linear range of detection, and moderate affinity for xylitol [9].
• Therefore, to prevent end-stage renal failure in these patients, important clinical factors should be considered as indicators for the underlying cause: history of alcohol abuse and severe high anion gap acidosis for ethylene glycol intoxication or history of long-lasting parenteral nutrition for xylitol-associated acute renal failure [10].

High impact information on xylitol

• This conclusion is supported by the finding that chronic xylose feeding, despite being associated with intracellular xylitol accumulation, does not result in alterations in AR mRNA levels, at least in the kidney [11].
• Transient expression of an AtPLT5-green fluorescent protein fusion in plant cells and functional analyses of the AtPLT5 protein in yeast and Xenopus oocytes demonstrate that AtPLT5 is located in the plasma membrane and characterize this protein as a broad-spectrum H+-symporter for linear polyols, such as sorbitol, xylitol, erythritol, or glycerol [12].
• We found that the five-carbon sugar xylitol has a low transepithelial permeability, is poorly metabolized by several bacteria, and can lower the ASL salt concentration in both CF and non-CF airway epithelia in vitro [13].
• We determined here the effects of two histone deacetylase inhibitors, sodium butyrate and the stable prodrug xylitol butyrate derivative (D1), on a t(8;21)-positive cell line (Kasumi-1) as well as primary AML blasts [14].
• Similarly, xylitol, an NADH-generating compound, enhanced hepatocyte ROS production and decreased viability [15].

Chemical compound and disease context of xylitol

• When Klebsiella aerogenes was grown in continuous culture with xylitol. an unnatural pentitol, as the growth limiting substrate, the structural gene which codes for ribitol dehydrogenase, an enzyme which gratuitously catalyzes the oxidation of xylitol to D-xylulose, was duplicated [16].
• Streptococcus mutans: Fructose Transport, Xylitol Resistance, and Virulence [17].
• The lack of an effect of fluoride and xylitol on plaque acid metabolism is attributed to the variability of dental plaque and the low concentrations of active ingredients reaching the plaque [18].
• An Erwinia uredovora mutant which constitutively synthesized a novel xylitol-4-dehydrogenase but could not synthesize L-xylulokinase was used for the oxidation of xylitol to L-xylulose [19].
• The results suggest that oxalate production from xylitol is negligible; any toxicity related to xylitol administration is not a consequence of oxalate production [20].

Biological context of xylitol

• The phosphate was localized on the C-2 of the chain initiating xylose since these residues as xylitol showed a delayed release during acid hydrolysis and the xylitol was recovered intact after periodate oxidation [21].
• The location of the active site in the enzyme has been tentatively identified from studies using a crystal grown from a solution containing the inhibitor xylitol [22].
• The effect of xylitol on the induction of the L-PK gene expression was noncumulative with that of glucose since 20 mM glucose plus 5 mM xylitol induced the expression of the L-PK/CAT construct similarly to 20 mM glucose alone [23].
• Effects of xylitol on gastric emptying and food intake [24].
• Food intake after oral preloading with water resulted in intake of 920 +/- 60 kcal vs 690 +/- 45 kcal after 25 g of xylitol [24].

Anatomical context of xylitol

• If xylitol reduces the growth of S. pneumoniae in the nasopharynx, it could also reduce the carriage of this pathogen and thus have clinical significance in the prevention of pneumococcal diseases [25].
• The exposure of either epithelial cells or pneumococci or both to 5% xylitol reduced the adherence of pneumococci [26].
• The effect of long-term consumption of refined xylitol on the natural populations of S. mutans in the human oral cavity has been investigated [27].
• Rats adapted to dietary xylitol did not have detectable levels of C. perfringens in the gastrointestinal tract [28].
• These non-adapted rats had significantly higher levels of intestinal tract Clostridium perfringens (10(6)--10(11) organisms per gram intestinal contents) than did control rats fed a xylitol-free cornstarch diet (0-10(4) organisms per gram) [28].

Associations of xylitol with other chemical compounds

• myo-Inositol oxygenase (MIOX) catalyzes the oxidative cleavage of myo-inositol (MI) to give d-glucuronic acid, a committed step in MI catabolism. d-Glucuronic acid is further metabolized to xylitol via the glucuronate-xylulose pathway [4].
• The NADH redox state was also elevated by xylitol, causing a 75% decrease in rates of methanol uptake by livers from fasted rats [29].
• In 14 insulin-dependent diabetics a standard diabetic diet regimen was compared with diets in which starch was isocalorically exchanged in the breakfast meal by either 30 g xylitol or 30 g sucrose [30].
• Plasma insulin response to arginine was exaggerated by xylitol infusion.Repeated arginine pulses given at 30 min intervals evoked uniphasic and almost identical rises of plasma insulin and glucagon with each pulse [31].
• With the glycemic index of glucose as 100, the indexes of xylitol and lactitol were 7 and -1, respectively [32].

Gene context of xylitol

• These results suggest that the expression of MIOX is up-regulated by a positive feedback mechanism where xylitol, one of the products of MI catabolism via the glucuronate-xylulose pathway, induces an overexpression of MIOX [4].
• In recombinant strains from which the GRE3 gene was deleted, xylitol formation decreased twofold [33].
• The Pichia stipitis CBS 6054 genes XYL1 and XYL2 encoding xylose reductase and xylitol dehydrogenase were cloned into S. cerevisiae [34].
• However, overexpression of XKS1 shifted polyol formation from xylitol to arabinitol [35].
• The glpF protein allowed the rapid efflux of preequilibrated xylitol [36].

Analytical, diagnostic and therapeutic context of xylitol

• Furthermore, in a double-blind, randomized, crossover study, xylitol sprayed for 4 days into each nostril of normal volunteers significantly decreased the number of nasal coagulase-negative Staphylococcus compared with saline control [13].
• Xylitol has been suggested as a potentially useful sweetener in the diabetic diet [30].
• A detailed quantitative study of the urinary organic acid excretion by means of gas chromatography/mass spectrometry showed that there was an abnormal glycolic aciduria and tetronic aciduria associated with xylitol infusion, but not with glucose infusion [37].
• Differential peptide mapping between D-xylose isomerase, which has previously been treated with diethyl pyrocarbonate in the presence or absence of xylitol plus Mg2+, allowed specific isolation and sequencing of a peptide containing this active-site histidine [38].
• An additional control group was fed diet SSP 20/5 supplemented with 5% xylitol [39].

References