Measurement of Antioxidant Activity and Capacity by Apak Reşat. Çapanoğlu Esra. Shahidi Fereidoon & Esra Capanoglu & Fereidoon Shahidi

Author:Apak, Reşat.,Çapanoğlu, Esra.,Shahidi, Fereidoon & Esra Capanoglu & Fereidoon Shahidi
Language: eng
Format: epub
ISBN: 9781119135371
Publisher: John Wiley & Sons, Inc.
Published: 2018-02-05T00:00:00+00:00

9

Biomarkers of oxidative stress and cellular‐based assays of indirect antioxidant measurement

Cheng Yang1, Fereidoon Shahidi2, and Rong Tsao3

1 Guelph Research and Development Centre, Agriculture and Agri‐Food Canada, Guelph, Ontario, Canada

2 Department of Biochemistry, Memorial University of Newfoundland, St John’s, Newfoundland, Canada

3 Guelph Research and Development Centre, Agriculture and Agri‐Food Canada, Guelph, Ontario, Canada

9.1 Introduction

Oxidative stress is defined as the imbalance between reactive oxygen or nitrogen species (ROS/RNS) production and the antioxidant defense, and has been reported to play a key role in the pathology of several chronic diseases, including cardiovascular, cancer, neurodegenerative ailments, and the aging process (Flora 2006; Halliwell & Gutteridge 2015). For this reason, antioxidants, particularly dietary antioxidants, can be beneficial to human health owing to their ability to reduce oxidative stress via antioxidant activity (Griep et al. 2010; Hung et al. 2004; Joshipura et al. 2001). A large number of assay methods has been developed to assess the antioxidant capacity of natural products, especially those of foods (Carocho & Ferreira 2013; Lopez‐Alarcon & Denicola 2013). These assay methods are either based on hydrogen atom transfer (HAT) or electron transfer (ET) or both. While these methods have been widely used, they cannot be compared, nor can their results be directly and accurately extrapolated to in vivo performance. Besides, the physiological antioxidant action is not only about scavenging free radicals but also includes upregulation of detoxifying enzymes and antioxidant defense, modulation of gene expression and redox cell signaling at the cellular level, therefore cell‐based antioxidant assays are considered more biologically relevant (Lopez‐Alarcon & Denicola 2013). Animal models and human studies are more suitable/convincing, but they are costly and time‐consuming, which makes the cell‐based assays very attractive as an intermediate or indirect testing method for antioxidant capacity/ability. Recently, many biomarkers have been identified and used in new approaches to the cell‐based antioxidant assays and as indirect measurements for antioxidant activity.

Some of the biomarkers used in cellular‐based assays of indirect antioxidant measurement are compounds of cellular activities including the oxidation of vital biomolecules. This chapter will therefore first review cellular levels of free radicals and oxidative stress (OS), and the formation of OS biomarkers produced as a result of oxidation or oxidative damage to different biomolecules, and then the latest research on using these biomarkers in cell‐based assay. The mechanisms behind such antioxidant actions inside the cells are reviewed. Meanwhile, biomarkers can also be cell signaling chemicals related to OS. Indirect antioxidant measurements of compounds through monitoring activation of redox transcription factors and inhibition of oxidases or activation of antioxidant enzymes are discussed. The advantages and disadvantages of different measurements in cellular‐based assay systems are also covered.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.