Effects of Glutathione and Ascorbic Acid on Streptomycin Sensitivity of Escherichia coli

ABSTRACT We examined the effects of antioxidants and the role of reactive oxygen species (ROS) on the antibacterial action of aminoglycosides in Escherichia coli. We concluded that reduced streptomycin sensitivity in the presence of glutathione and ascorbic acid is not due to the antioxidant-mediated scavenging of ROS.

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Extremely enhanced contaminant decomposition catalyzed by hemin via the coupling of persistent free radicals and ascorbic acid

Chemical Communications ◽

10.1039/c5cc07070h ◽

2015 ◽

Vol 51 (89) ◽

pp. 16139-16142 ◽

Cited By ~ 6

Author(s):

Yuyuan Yao ◽

Bin Jiang ◽

Yajun Mao ◽

Juan Chen ◽

Zhenfu Huang ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Ascorbic Acid ◽

Free Radicals ◽

Reactive Oxygen ◽

Environmental Pollutant ◽

Ros Generation ◽

Oxygen Species ◽

Positive Role ◽

Rate Enhancement

A positive role of PFRs in enhancing reactive oxygen species (ROS) generation for an extreme rate enhancement in environmental pollutant decomposition is reported.

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Ascorbic acid improves mitochondrial function in liver of arsenic-treated rat

Toxicology and Industrial Health ◽

10.1177/0748233710365694 ◽

2010 ◽

Vol 26 (5) ◽

pp. 265-272 ◽

Cited By ~ 16

Author(s):

Sohini Singh ◽

Suresh Vir Singh Rana

Keyword(s):

Reactive Oxygen Species ◽

Ascorbic Acid ◽

Mitochondrial Function ◽

Caspase 3 ◽

Succinic Dehydrogenase ◽

Reactive Oxygen ◽

Ultrastructural Changes ◽

Arsenic Toxicity ◽

Oxygen Species

Arsenic is an ubiquitous and well-documented carcinogenic metalloid. The most common source of arsenic is drinking water. The mechanism of arsenic toxicity in a cell has historically been centered around its inhibitory effects on cellular respiration and mitochondrial injury. Ascorbic acid, a low molecular weight, water-soluble antioxidant, improves the reduced glutathione (GSH) status by recycling oxidized glutathione. Ascorbic acid can improve mitochondrial function by improving the thiol status; thereby preventing reactive oxygen species— mediated damage to liver as well as kidney. Ascorbic acid has been shown to protect membrane and other cellular compartments by regenerating vitamin E. Therefore, ascorbic acid seems to be a suitable protective factor against arsenic toxicity. Present reports describe the effect of ascorbic acid on oxidative phosphorylation, adenosine triphosphatase (ATPase), succinic dehydrogenase, caspase-3 and apoptosis in the liver of rats treated with arsenic trioxide (AsIII). Ultrastructural changes in the mitochondria have also been reported. We show that cotreatments with ascorbic acid and AsIII improve mitochondrial structure and function. We attribute these improvements mainly to antioxidative role of ascorbic acid. Apoptosis was restricted due to caspase-3 inhibition. Ascorbic acid could protect DNA from the attack of reactive oxygen species generated by AsIII. Consequently its events led to improved ADP:O ratio, normalized ATPase activity and restored the activity of succinic dehydrogenase. Overall, results support the protective role of ascorbic acid against As III-induced liver injury.

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Involvement of Reactive Oxygen Species in the Action of Ciprofloxacin against Escherichia coli

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.50.3.949-954.2006 ◽

2006 ◽

Vol 50 (3) ◽

pp. 949-954 ◽

Cited By ~ 118

Author(s):

M. Goswami ◽

S. H. Mangoli ◽

N. Jawali

Keyword(s):

Escherichia Coli ◽

Reactive Oxygen Species ◽

Reactive Oxygen ◽

Antibacterial Action ◽

Antioxidant Compounds ◽

Oxygen Species ◽

Bacterial Cells ◽

Topoisomerase Iv ◽

Dna Topoisomerase ◽

E Coli

ABSTRACT Ciprofloxacin is an important and commonly used member of the fluoroquinolone group of antibiotics. Ciprofloxacin inhibits DNA topoisomerase II and DNA topoisomerase IV activities, eventually leading to bacterial cell death. In addition, an increase of reactive oxygen species in the bacterial cells in response to ciprofloxacin has been shown. We investigated the role of reactive oxygen species in the antibacterial action of ciprofloxacin by studying the effects of different antioxidant compounds on ciprofloxacin susceptibility of Escherichia coli. Among the antioxidants checked, glutathione and ascorbic acid provided substantial protection against ciprofloxacin. The involvement of superoxide anion (O2 −) and hydrogen peroxide (H2O2) in the antibacterial action of ciprofloxacin was analyzed using superoxide dismutase, catalase, and alkyl hydroperoxide reductase knockout strains of E. coli. The effects of multicopy sod genes on ciprofloxacin susceptibility of E. coli were also analyzed. On the basis of our results, we conclude that O2 − and H2O2 may be involved in antibacterial action of ciprofloxacin. Our findings that glutathione gave protection against other fluoroquinolones and not against nonfluoroquinolone antibiotics imply that reactive oxygen species may have a similar role in the antibacterial action of all these fluoroquinolones and that glutathione-mediated protection is not a general phenomenon but specific to fluoroquinolones. These observations are of significance, as fluoroquinolones are important antibiotics with immense therapeutic value, and the effectiveness of treatment by these drugs may be affected by dietary intake and cellular levels of these antioxidants.

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