Acetaldehyde production from ethanol and glucose by non-Candidaalbicans yeasts in vitro
Received 17 July 2009; received in revised form 5 August 2009; accepted 5 August 2009. published online 30 September 2009.
Summary
Background
Major environmental risk factors for upper digestive tract cancers are tobacco smoking, alcohol intake and poor oral hygiene. They all result in increased acetaldehyde (ACH) levels in saliva which has been shown to be carcinogenic. During alcohol challenge the oral microbiota is the main determinant of the local ACH concentration. Many bacteria and Candida albicans have been shown to be capable of ACH production. Moreover, chronic candidal mucositis can be carcinogenic. The ability of non-C. albicansCandida to produce ACH has not been studied.
Aim
The aim of this study was to explore the ability of non-C. albicansCandida species to produce ACH in vitro during ethanol and glucose incubation.
Methods
A total of 30 non-C. albicansCandida isolates and one C. albicans reference strain were used. The cells were exposed to 11mM of ethanol and to 100mM glucose in vitro. ACH was measured by gas chromatography.
Results
All Candida isolates produced significant amounts of ACH in ethanol incubation. C. tropicalis isolates were the highest (252.3μM) and C. krusei isolates were the lowest (54.6μM) producers of ACH from ethanol. Only C.glabrata produced significant amounts of ACH by fermentation from glucose.
Conclusion
Colonization of oral mucosa with a non-C.albicans species such as C. glabrata, capable of producing carcinogenic amounts of ACH from both ethanol and glucose, may contribute to the development of oral cancer.
aResearch Unit on Acetaldehyde and Cancer, Faculty of Medicine, University of Helsinki, Helsinki, Finland
bDepartment of Oral Medicine, Institute of Dentistry, University of Helsinki, Helsinki, Finland
cDepartment of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland
dDepartment of Oral and Maxillofacial Diseases, Helsinki University Hospital, Helsinki, Finland
eThe University of Manchester, Manchester Academic Health Science Centre, School of Translational Medicine and University Hospital of South Manchester, Wythenshawe Hospital, Southmoor Road, Manchester M23 9LT, UK
Corresponding author. Address: Education and Research Centre, 2nd Floor, Wythenshawe Hospital, Southmoor Road, Manchester M23 9LT, UK. Tel.: +44 75 4599 4959; fax: +44 161 291 5806.
ABSTRACT