Tutkimus: Ksylitoli ehkäisee syöpää

 

 


Volume 129, Issue 8
15 October 2011
Pages 2038–2041

Short Report

Xylitol inhibits carcinogenic acetaldehyde production by Candida species

Authors

Johanna Uittamo,

Corresponding author

E-mail address: johanna.uittamo@helsinki.fi

  1. Research Unit on Acetaldehyde and Cancer, University of Helsinki, Helsinki, Finland

  2. Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland

  3. Research Unit on Acetaldehyde and Cancer, University of Helsinki, Biomedicum Helsinki, PL 700, 00029 HUS, Helsinki, Finland

Mikko T. Nieminen,

  1. Research Unit on Acetaldehyde and Cancer, University of Helsinki, Helsinki, Finland

  2. Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland

  3. Department of Oral Medicine, Institute of Dentistry, University of Helsinki, Helsinki, Finland

Pertti Kaihovaara,

Research Unit on Acetaldehyde and Cancer, University of Helsinki, Helsinki, Finland

Paul Bowyer,

The University of Manchester, Manchester Academic Health Science Centre, School of Translational Medicine and University Hospital of South Manchester, Manchester, United Kingdom

Mikko Salaspuro,

Research Unit on Acetaldehyde and Cancer, University of Helsinki, Helsinki, Finland

Riina Rautemaa

  1. Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland

  2. Department of Oral Medicine, Institute of Dentistry, University of Helsinki, Helsinki, Finland

  3. The University of Manchester, Manchester Academic Health Science Centre, School of Translational Medicine and University Hospital of South Manchester, Manchester, United Kingdom

  4. Department of Oral and Maxillofacial Diseases, Helsinki University Central Hospital, Helsinki, Finland 


Abstract

Acetaldehyde is a highly toxic and mutagenic product of alcohol fermentation and metabolism which has been classified as a Class I carcinogen for humans by the International Agency for Research on Cancer of the World Health Organisation (WHO).

Many Candida species representing oral microbiota have been shown to be capable of marked acetaldehyde production. The aim of our study was to examine the effects of various sugar alcohols and sugars on microbial acetaldehyde production. The study hypothesis was that xylitol could reduce the amount of acetaldehyde produced by Candida. Laboratory and clinical isolates of seven Candida species were selected for the study. The isolates were incubated in 12 mM ethanol and 110 mM glucose, fructose or xylitol at 37°C for 30 min and the formed acetaldehyde was measured by gas chromatography.Xylitol significantly (p < 0.0001) reduced the amount of acetaldehyde produced from ethanol by 84%. In the absence of xylitol, the mean acetaldehyde production in ethanol incubation was 220.5 μM and in ethanol–xylitol incubation 32.8 μM. This was found to be mediated by inhibition of the alcohol dehydrogenase enzyme activity. Coincubation with glucose reduced the amount of produced acetaldehyde by 23% and coincubation with fructose by 29%. At concentrations that are representative of those found in the oral cavity during the intake of proprietary xylitol products, xylitol was found to reduce the production of carcinogenic acetaldehyde from ethanol by Candida below the mutagenic level of 40–100 μM. 

Acetaldehyde is a highly toxic and mutagenic product of alcohol fermentation and metabolism.
Recently, acetaldehyde was reclassified as a Class I carcinogen for humans by the International Agency for Research on Cancer of WHO.1 Mutagenicity can take place at concentrations as low as 40–100 μM of acetaldehyde.2 
Microbes possessing alcohol dehydrogenase (ADH) activity can produce acetaldehyde by ethanol oxidation.3 
This reaction takes place in the oral cavity when consuming alcohol and it continues for as long as there is ethanol in saliva.4 Due to the equal distribution of ethanol to the fluid compartments of the body its concentration in saliva is the same as in the blood and its clearance is nonlinear in both.5 Streptococcus viridans and Neisseria group bacteria belonging to the core oral microbiota have been shown to be able to produce significant amounts of acetaldehyde from ethanol.6, 7 Furthermore, many Candida species representing the normal oral flora of the vast majority of the population have been shown to be capable of even more marked acetaldehyde production.8–10 Microbial acetaldehyde production is one of the key mechanisms in the cumulative exposure to carcinogenic acetaldehyde.11

Candida species can produce significant amounts of acetaldehyde also by alcohol fermentation from glucose.

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