title: Effects of the phenolic contents of Mauritian endemic plant extracts on promoter activities of antioxidant enzymes.
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.
authors.affiliation: Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan. toyokuni@path1.med.kyoto-u.ac.jp
authors.forename: Shinya
authors.initials: S
authors.lastname: Toyokuni
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Waka
authors.initials: W
authors.lastname: Kawaguchi
authors.forename: Neil Ryan Lai
authors.initials: NR
authors.lastname: Fang
authors.forename: Munetaka
authors.initials: M
authors.lastname: Ozeki
authors.forename: Shinya
authors.initials: S
authors.lastname: Akatsuka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hiai
authors.forename: Okezie I
authors.initials: OI
authors.lastname: Aruoma
authors.forename: Theeshan
authors.initials: T
authors.lastname: Bahorun
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D019556:COS Cells; D002374:Catalase / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D005979:Glutathione Peroxidase / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D008297:Male; D008436:Mauritius; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D010545:Peroxides / Q000378:metabolism; D010636:Phenols / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D011401:Promoter Regions, Genetic / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000235:genetics
chemical_list: D000975:Antioxidants; D010545:Peroxides; D010636:Phenols; D010936:Plant Extracts; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase