Dietary phenolic acids and ascorbic acid: influence on acid-catalyzed nitrosative chemistry in the presence and absence of lipids

Combet, E., Elmesmari, A., Preston, T., Crozier, A. and McColl, K.E.L. (2010) Dietary phenolic acids and ascorbic acid: influence on acid-catalyzed nitrosative chemistry in the presence and absence of lipids. Free Radical Biology and Medicine, 48(6), pp. 763-771. (doi:10.1016/j.freeradbiomed.2009.12.011)

Combet, E., Elmesmari, A., Preston, T., Crozier, A. and McColl, K.E.L. (2010) Dietary phenolic acids and ascorbic acid: influence on acid-catalyzed nitrosative chemistry in the presence and absence of lipids. Free Radical Biology and Medicine, 48(6), pp. 763-771. (doi:10.1016/j.freeradbiomed.2009.12.011)

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Abstract

Acid-catalyzed nitrosation and production of potentially carcinogenic nitrosative species is focused at the gastroesophageal junction, where salivary nitrite, derived from dietary nitrate, encounters the gastric juice. Ascorbic acid provides protection by converting nitrosative species to nitric oxide (NO). However, NO may diffuse into adjacent lipid, where it reacts with O2 to re-form nitrosative species and N-nitrosocompounds (NOC). In this way, ascorbic acid promotes acid nitrosation. Using a novel benchtop model representing the gastroesophageal junction, this study aimed to clarify the action of a range of water-soluble antioxidants on the nitrosative mechanisms in the presence or absence of lipids. Caffeic, ferulic, gallic, or chlorogenic and ascorbic acids were added individually to simulated gastric juice containing secondary amines, with or without lipid. NO and O2 levels were monitored by electrochemical detection. NOC were measured in both aqueous and lipid phases by gas chromatography-tandem mass spectrometry. In the absence of lipids, all antioxidants tested inhibited nitrosation, ranging from 35.9 Ý 7.4% with gallic acid to 93 Ý 0.6% with ferulic acid. In the presence of lipids, the impact of each antioxidant on nitrosation was inversely correlated with the levels of NO they generated (R2 = 0.95, p < 0.01): gallic, chlorogenic, and ascorbic acid promoted nitrosation, whereas ferulic and caffeic acids markedly inhibited nitrosation.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Preston, Professor Thomas and Elmesmari, Dr Aziza and McColl, Professor Kenneth and Combet Aspray, Dr Emilie and Crozier, Professor Alan
Authors: Combet, E., Elmesmari, A., Preston, T., Crozier, A., and McColl, K.E.L.
Subjects:Q Science > QH Natural history > QH345 Biochemistry
College/School:College of Medical Veterinary and Life Sciences > Institute of Cardiovascular and Medical Sciences
College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Clinical Specialities
College of Science and Engineering > Scottish Universities Environmental Research Centre
College of Medical Veterinary and Life Sciences > Institute of Infection Immunity and Inflammation
Journal Name:Free Radical Biology and Medicine
ISSN:0891-5849
ISSN (Online):1873-4596
Published Online:21 December 2009

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
369511Influence of lipids on nN-nitrosative chemistry arising from dietary nitrate at the gastro-oesophagal junctionKenneth MccollWorld Cancer Research Fund (WCRF-LOND)2004/13RI CARDIOVASCULAR & MEDICAL SCIENCES