Correlation Between Antioxidant Activity And Biological Chemoprotection
The study of the biological effects of oxidative stress is vital to the understanding of tissue damage, cell ageing and disease. The continued study of antioxidants and their ability to defend organisms against oxidation may thus have potential health benefits. This research focuses on the biological effects of antioxidants as compared to their ability to protect linoleic acid from oxidation. Linoleic acid is a compound commonly found in cell membranes and may play a role in oxidative damage to cells. The ability of an antioxidant to protect linoleic acid from oxidation may not necessarily have the same ability to protect mammalian cells. In this research, a novel ferric thiocyanate (FTC) microplate-based assay is used to measure antioxidant activity. Chinese Hamster Ovary (CHO) cells are then exposed to a range of concentrations of antioxidant test compound, and the results show the biological effects of the antioxidant. The antioxidant ascorbic acid (Vitamin C), when exposed to linoleic acid, has an I50 value of 1.67 mM (this value indicates the concentration that protects 50% of the linoleic acid from oxidation). However, this concentration is lethal for CHO cells. An ascorbic acid concentration range of 0.5-2.5 mM results in cellular cytotoxicity rather than cell rescue from the oxidant H2O2. The cytotoxicity assay reveals that it is possible to kill cells with an overdose of ascorbic acid. The cell rescue assay with ascorbic acid will be repeated until the concentration that protects cells without killing them is found. This data will provide a clearer picture of the mechanisms for protection.
School:
University of Illinois at Urbana-Champaign
Department:
Biology
Research Advisor:
Michael Plewa
Department of Research Advisor:
Crop Sciences
Year of Publication:
2003