1. Effects of the phenolic contents of Mauritian endemic plant extracts on promoter activities of antioxidant enzymes.
- Author
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Toyokuni S, Tanaka T, Kawaguchi W, Fang NR, Ozeki M, Akatsuka S, Hiai H, Aruoma OI, and Bahorun T
- Subjects
- Animals, COS Cells, Catalase genetics, Glutathione Peroxidase genetics, HeLa Cells, Humans, Male, Mauritius, Microscopy, Confocal, Molecular Sequence Data, Peroxides metabolism, Promoter Regions, Genetic physiology, Rats, Rats, Wistar, Superoxide Dismutase genetics, Antioxidants metabolism, Gene Expression Regulation, Enzymologic drug effects, Phenols pharmacology, Plant Extracts pharmacology, Promoter Regions, Genetic drug effects
- Abstract
Oxidative stress has been associated with a variety of pathologic conditions in humans. Increasing the transcriptional activities of antioxidant enzymes might be a strategy to prevent oxidative stress-associated diseases such as atherosclerosis and cancer. In the present paper, we studied the effects of extracts from 12 Mauritian endemic plants on the promoter activities of antioxidant enzymes; Cu, Zn-superoxide dismutase (Cu,Zn-SOD), Mn-superoxide dismutase (Mn-SOD), catalase, and glutathione dismutase (GPx). The levels of total phenolic compounds, total flavonoids, and proanthocyanidins were measured. Four luciferase expression vectors (pGL3-Basic) with promoter region of each enzyme were constructed, transfected to COS7 cells followed by an exposure to each extract (25 microg/ml, 24h, non-toxic dose). Thereafter, luciferase activities were evaluated in comparison with a control luciferase vector with a herpes simplex virus thymidine kinase promoter. Mauritian endemic plants contained high amounts of total phenols, flavonoids and proanthocyanidins. Total phenols and flavonoids were proportionally associated with Cu,Zn-SOD promoter activity, whereas they were inversely correlated with catalase promoter activity. These results suggest that the chemopreventive potentials of the extracts might reside in their abilities to modulate the expression of the antioxidant enzyme genes.
- Published
- 2003
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