Abstract
The study of the mechanisms involved in cell damage mediated by oxidative compounds as well as the evaluation of biomarkers of the cellular antioxidant defence system in such conditions could help to prevent appearance and development of oxidative stress related diseases. The present overview describes a model of oxidative stress in cultured cells based on the evaluation of cellular antioxidant defences and suitable to assay the possible chemopreventive effect of dietary compounds. Since the liver is the major place for xenobiotic metabolism, research on chemopreventive compounds should focus on the response of liver cells. Human HepG2, a well differentiated transformed cell line from hepatic origin, is a reliable model widely used for biochemical and nutritional studies where many compounds and conditions can be assayed with minor inter-assay variations. The products selected for this overview are representative of different constituents included in the human diet and possess diverse structures and mechanisms of antioxidant activity: phenolic compounds such as quercetin and hydroxytyrosol, a Maillard reaction product such as coffee melanoidin and an oligoelement such as a selenium derivative. The results confirm the reliability of the model and give more insight into the specific mechanisms involved in the biological activity of the tested compounds.
Keywords: Antioxidant defences, biomarkers of oxidative stress, dietary antioxidants, polyphenols, melanoidins, selenium
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