A Compendium of Volatile Organic Compounds (VOCs) Released By Human Cell Lines

Abstract

Volatile organic compounds (VOCs) offer unique insights into ongoing biochemical processes in healthy and diseased humans. Yet, their diagnostic use is hampered by the limited understanding of their biochemical or cellular origin and their frequently unclear link to the underlying diseases. Major advancements are expected from the analyses of human primary cells, cell lines and cultures of microorganisms. In this review, a database of 125 reliably identified VOCs previously reported for human healthy and diseased cells was assembled and their potential origin is discussed. The majority of them have also been observed in studies with other human matrices (breath, urine, saliva, feces, blood, skin emanations). Moreover, continuing improvements of qualitative and quantitative analyses, based on the recommendations of the ISO-11843 guidelines, are suggested for the necessary standardization of analytical procedures and better comparability of results. The data provided contribute to arriving at a more complete human volatilome and suggest potential volatile biomarkers for future validation. Dedication: This review is dedicated to the memory of Prof. Dr. Anton Amann, who sadly passed away on January 6, 2015. He was motivator and motor for the field of breath research.

Endogenous and microbial volatile organic compounds in cutaneous health and disease

“…There will be a need for VOC libraries specific to skin to permit rapid identification of compounds in a patient's sample [20]. This will likely be supported by investigations into the production of volatile metabolites at the cellular [49] and microbial [99] levels. Meeting these needs will support development of tailored recognition elements within sensor arrays for maximum selectivity and sensitivity based on pre-evaluated volatile profiles.…”

“…A library of endogenous VOCs has been proposed based on volatile profiling of human cell lines [49]. Analysis of VOCs in human primary cells, cell lines and cultures of microorganisms is expected to provide invaluable insights into the biochemistry of volatile compounds observed in humans.…”

Human skin volatiles: Passive sampling and GC × GC-ToFMS analysis as a tool to investigate the skin microbiome and interactions with anthropophilic mosquito disease vectors

“…Several publications have probed the human skin volatilome in recent years [6]. Endogenous volatiles making up the human skin volatilome originate from both human cells and the resident skin microflora [7]. The surface of human skin forms a unique microbiome which is colonized by a cohort of endogenous microflora.…”

Evaluation of peroxidative stress of cancer cells in vitro by real‐time quantification of volatile aldehydes in culture headspace

“…Inspection of these bar charts reveals that the headspace concentrations of all the aldehydes fall over time, presumably because of either metabolism by the cancer cells due to aldehyde dehydrogenases expression or chemical reactions possibly forming diols (hydrates). Pentanal and heptanal are marginally the major products of peroxidation stress in this scenario, reaching about 200 ppbv in the headspace.…”

“…Aldehyde production has a rapid onset when the electrode potential increases beyond about –2 V, reaching a maximum of about 600 ppbv for heptanal and about 400 ppbv for pentanal. The headspace concentrations of all the aldehydes first peak then decrease as ROS production, and hence cellular production, slow down whilst losses continue from the headspace due to sampling into the SIFT‐MS instrument and metabolism by the cell culture . A control experiment in which the headspace of the gel/electrolyte/CALU‐1 cells culture was analyzed for 45 min without electrochemical excitation resulted in maximal concentrations of hexanal of 40 ppbv and propanal 30 ppbv, with all other aldehydes below 20 ppbv.…”