Detection of Oxidative Stress Associated Protein Markers Induced by Acrylamide and its Active Metabolite
Acrylamide is a known neurotoxin and a suspected carcinogen in human, it may be generated in the cooking process when asparagine reacts with reducing sugars. Recent studies indicate that acrylamide is associated with many cancers. High acrylamide concentrations in food may increase cancer risk in humans. Acrylamide and glycidamide, its epoxide metabolite, are highly reactive chemicals that readily form acrylamide or glycidamide protein adducts, which are useful biological markers of acrylamide exosure. Acrylamide also can increase reactive oxygen species production leading to cell damage and protein damage.
Curcumin is a phytochemical polyphenol and is widely used as preservative, flavouring and colouring agent in beverages and in foods. For centuries, curcumin has also been widely used in traditional remedies for various dental diseases and digestive disorders. Many studies also show that curcumin fights many diseases, including Alzheimer’s disease, cancers, inflammatory diseases, pulmonary dysfunction, the common cold, diabetes, and liver diseases. Curcumin has powerful antioxidant properties and recent studies show that curcumin can attenuate acrylamide-induced cytotoxicity and genotoxicity due to the scavenging of reactive oxygen species.
Hence, this study used nano ultra performance liquid chromatographic system (nanoUPLC) coupled with tandem mass spectrometry (MS/MS) to profile liver cell proteins after curcumin and acrylamide treatment. Several proteins and protein modifications induced by acrylamide exposure were identified. Hundreds of proteins were identified in liver cells and several proteins were identified after acrylamide exposure. Many peptides revealed specific modifications by acrylamide, including nitrosylation (in cysteine) and hydroxylation (in aspartic acid, lysine, proline and asparagine). The results indicate that curcumin can reduce the effects of acrylamide. Human health applications of these proteins and protein modifications include indicators for clinical diagnosis of the effects of long-term acrylamide exposure.
Index Terms- Oxidative stress, protein markers, acrylamide, curcumin, mass spectrometry.