Assays for superoxide dismutase (SOD) and catalase (CAT) activities are widely employed to indicate antioxidant responses underlying the toxic effects of test chemicals. Yet, earlier studies mainly described the procedures as performed according to manufacturer’s instructions without modifications that are specific to any organisms. The present protocol describes the steps in analyzing the superoxide dismutase (SOD) and catalase (CAT) activities in C. elegans, which is a model organism that can be used to study effects of pharmaceutical compounds and environmental pollutants. The main steps include: (1) sample preparation; (2) total protein assay; (3) SOD activity assay; (4) CAT activity assay; and (5) medium list and formula, and also data analysis and performance notes.
Keywords: SOD, CAT, Total protein, C. elegans, Protocol
Biomarkers are essential to examine biological and pathogenic processes in response to a chemical, an agent or a therapeutic intervention. Various biological processes in organisms result in reactive oxygen species (ROS) which cause oxidative stress. In response to such oxidative stress, organisms can deploy superoxide dismutase (SOD) and catalase (CAT) to scavenge ROS so as to protect the cellular homeostasis (Balaban et al., 2005). On the one hand, various chemicals (pollutants) can retard such antioxidant responses, and disturb the health of organisms including human beings. On the other hand, many pharmaceuticals aim to strengthen the antioxidant responses to improve health. Therefore, activities of SOD and CAT are very important to reflect potential effects of chemicals or/and pharmaceuticals.
Caenorhabditis elegans (C. elegans) is a model organism that has been used to study effects of pharmaceutical compounds (Dengg and van Meel, 2004; Carretero et al., 2017) and environmental pollutants (Yu et al., 2013a and 2017). Several studies have used SOD and CAT assays to indicate the antioxidant responses and potential mechanism underlying the toxic effects of test chemicals (Feng et al., 2015; Yu et al., 2012; 2016 and 2017). However, these studies simply described that the determination was carried out, by using a generic kit protocol without species-specific modifications. Therefore, the explicit protocols to perform SOD and CAT assays in C. elegans are still needed for better specific instruction.
In the present protocol, we provide a nematode protocol with experimental details to analyze SOD and CAT activities in C. elegans