Common food antimicrobials: effects on cellular inflammation and oxidative damage and their estimated occurrence in Singapore

Background and Objectives: The prevalence and potential health effects of common food antimicrobials in processed foods and beverages are relatively unknown in Singapore. The occurrence of chemical antimicrobials in processed foods and beverages and their effects on inflammation and oxidative stress in vitro were examined. Methods and Study Design: The occurrence of antimicrobials in 1605 processed food and 359 beverage items were examined by surveying the ingredients on the product labels. Human neutrophils were exposed to physio-logically relevant concentrations of common antimicrobials. Established markers of inflammation, l Leukotriene B4 and oxidative stress, F2-isoprostanes were measured using stable-isotope dilution gas chromatography-mass spectrometry. Results: Antimicrobials were added to 23.2% of the processed foods and beverages. Sorbic, benzo-ic, lactic, propionic and acetic acids accounted for 84.8% of the added antimicrobials in the processed foods and beverages. 92.5% of the bread contained propionic acid. Lactic acid was the most common antimicrobial (44.4%) in cheeses. Sorbic acid was added to 63.2% of the margarines selected. Sauces (31.5%), energy drinks (50.0%), soft drinks (70.7%) and fruit cordials (66.6%) contained added benzoic acid. Benzoic and propionic acids at physiologically relevant concentrations augmented leukotriene B4formation (benzoicacid, EC50 = 100 mcg L-1 and propionic acid, >200 mcg L-1). Lactic and sorbic acids dose-dependently inhibited the F2-isoprostanes production (IC50 values 100 mcg L-1) and myeloperoxidase activity (IC50values 100 mcg L-1). Conclusions: Our results demonstrate that Singapore consumers are significantly exposed to food antimicrobials, and these molecules, in physio-logically relevant concentrations, exert significant and differential effects in vitro.