DNA damage and intracellular generation of reactive oxygen species by allyl isothiocyanate inEscherichia coli

Yonezawa, Yusuke; Nishikawa, Katsuhiro; Nishioka, H.

doi:10.1002/(sici)1099-1301(199901/03)1:1<27::aid-jem8>3.0.co;2-6

Cited by 6 publications

(6 citation statements)

References 17 publications

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“…Scavenging by the flavonoids, before the radicals can reach and interact with the cellular DNA, helps in preserving the reproductive integrity of the cells, as indicated by the higher clonogenicity of the flavonoid-pretreated and irradiated cultures. Protection against DNA damage by orientin and vicenin is also reflected in the decrease in the H 2 O 2 -induced -galactosidase activity, as the latter is considered to be an index of DNA damage 8 . The protection was pronounced in the mutant strain deficient in the H 2 O 2 scavenging enzyme catalase.…”

Section: Discussionmentioning

confidence: 99%

“…The Escherichia coli strains DSH7 (wildtype), DSH19 (kat EG, deficient in catalase) and DSH56 (sod AB, deficient in SOD) 8 were used.…”

Section: Bacteriamentioning

confidence: 99%

“…2 x 10 8 cells, 2 ml titer) was incubated with different concentrations of orientin or vicenin (25 M, 50 M, 100 M, 200 M, 250 M, 500 M) for 30 min at 37 °C in a shaking water bath (30 rpm), followed by 0.125 ml of 1 mM menadione (final concentration 50 mM) for 1 h. The cells were then washed twice and resuspended in M9 buffer. Survival of the bacteria was determined by clonogenic assay 8 by plating cell suspensions on Luria bertini plates (in triplicate) after proper dilution and incubating at 37 °C. On the basis of the above experiments, 200 M orientin and vicenin were selected for the next experiment.…”

Section: Effect Of Orientin and Vicenin On Survival Of Dsh56 After Expomentioning

confidence: 99%

“…The optical density of the cell suspension was measured at 600 nm (OD 600 ) in a UV spectrophotometer (Shimazu, Japan). The -galactosidase test was carried out according to the method of Yonezawa 8 , et al Briefly, 0.1 ml of cell suspension and 0.02 ml of 10 per cent toluene were added to 1.9 ml of Z-buffer in a test tube and stirred vigorously to disrupt cell membranes. The test tube was then incubated at 37 °C for 40 min in a shaking water bath (100 rpm), and then at 28°C for 10 min.…”

Section: Effect Of Orientin and Vicenin On The H 2 O 2 -Induced -Galactmentioning

confidence: 99%

“…Two mutant strains of Escherichia coli , deficient in the enzymes catalase and superoxide dismutase, have been developed by Yonezawa 8 , et al Nishioka and Hayashi 9 have developed a method (the kat-sod assay) to study the reactive oxygen species generation in these strains. These bacterial strains were used to study the radioprotection by orientin and vicenin, and their antioxidant effect was studied by the kat-sod assay.…”

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Antioxidant and Radioprotective Effects of Ocimum Flavonoids Orientin and Vicenin in Escherichia coli

Nayak

Nishioka²,

Devi

2006

DSJ

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Antioxidant effect of the Ocimum flavonoids, orientin and vicenin (25-500 M), was evaluated by the kat-sod assay in Escherichia coli mutants (DSH56, superoxide dismutase-deficient and DSH19, catalase-deficient) treated with 50 mM menadione or H 2 O 2 (1mM). Protection by orientin (200 M) and vicenin (200 M) against H 2 O 2 -induced DNA damage in DSH19 cells ( -galactosidase test) and against radiation lethality in wild-type (DSH7) and DSH19 cells exposed to 0-150 Gy gamma radiation was also studied. Menadione and H 2 O 2 reduced the surviving fraction to 0.2 and 0.4 in DSH56 and DSH19 cells, respectively. Even 25 M of either flavonoid significantly increased the surviving fraction, with maximum protection at 200 M. H 2 O 2 increased thegalactosidase activity in a concentration-dependent manner, which was significantly (P < 0.050-0.001) reduced by orientin and vicenin (200 M). Radiation produced a dose-dependent decrease in the surviving fraction of both DSH7 and DSH19 cells. Pretreatment with 200 M orientin or vicenin significantly increased the survival (DRF: DSH7 = 2.2; DSH19 = 1.8). Both compounds were equally effective in reducing the cytotoxicity of radiation and the chemical oxidants. The cytoprotective action of these plant flavonoids could be ascribed to their free radical scavenging activity.

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Section: Discussionmentioning

confidence: 99%

“…The Escherichia coli strains DSH7 (wildtype), DSH19 (kat EG, deficient in catalase) and DSH56 (sod AB, deficient in SOD) 8 were used.…”

Section: Bacteriamentioning

confidence: 99%

Section: Effect Of Orientin and Vicenin On Survival Of Dsh56 After Expomentioning

confidence: 99%

Section: Effect Of Orientin and Vicenin On The H 2 O 2 -Induced -Galactmentioning

confidence: 99%

mentioning

confidence: 99%

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Antioxidant and Radioprotective Effects of Ocimum Flavonoids Orientin and Vicenin in Escherichia coli

Nayak

Nishioka²,

Devi

2006

DSJ

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Allyl isothiocyanate as a cancer chemopreventive phytochemical

Zhang

2010

Molecular Nutrition Food Res

207

162

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Allyl isothiocyanate (AITC), which occurs in many common cruciferous vegetables, is widely and often frequently consumed by humans. Besides antimicrobial activity against a wide spectrum of pathogens, it showed anticancer activity in both cultured cancer cells and animal models, although the underlining mechanisms remain largely undefined. Bioavailability of AITC is extremely high, as nearly 90% of orally administered AITC is absorbed. AITC absorbed in vivo is metabolized mainly through the mercapturic acid pathway and excreted in urine. Available data suggest that urinary concentrations of AITC equivalent are at least 10 times higher than in the plasma, and tissue levels of AITC equivalent in the urinary bladder were 14-79 times higher than in other organs after oral AITC administration to rats. These findings suggest that AITC may be most effective in the bladder as a cancer chemopreventive compound. AITC at high dose levels also exhibit a low degree of cytotoxicity and genotoxicity in animal studies, but such adverse effects are unlikely in humans exposed to dietary levels of AITC. Overall, AITC exhibits many desirable attributes of a cancer chemopreventive agent, and further studies are warranted in order to elucidate its mechanism of action and to assess its protective activity in humans.

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