Treatment of acute paraquat intoxication using recommended megadose of vitamin C

A reappraisal

J. B. Chang, C. C. Lin, J. F. Chiou, S. Y. Mau, T. Z. Liu, C. H. Chen

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Megadose of vitamin C (MVC) has been proposed for an emergent treatment of acute paraquat (PQ) poisoning. However, the safety issue of this treatment protocol has not been evaluated. Here, we present the first evidence that vitamin C can promote aggravated production of hydroxyl radical (OH ) via interacting with preexisting PQ+•/H2O2 system in a nonmetal-catalyzed manner. This enhanced oxidative stress would therefore expect to cause more deleterious effect during acute PQ intoxication. To lend support to this possibility, we set out to attest the effects of MVC on a simulated, PQ-intoxicated, Madin-Darby canine kidney (MDCK) cell model. First, PQ alone could trigger oxidative-nitrosative stress (ONS) through robust generation of reactive oxygen species and nitric oxide (NO) that could induce apoptotic killing via promoting effective release of mitochondrial cytochrome c, an apoptogenic factor. The percentage of apoptosis for MDCK cells treated with 1.0 mM PQ for 24 h was 16.3 ± 13.0%. However, when MDCK cells were treated with a combination of PQ (1.0 mM) and MVC (20 mM) for 24 h, the severity of apoptotic killing was further exacerbated as reflected by a nearly 7-fold increase in the release of mitochondrial cytochrome c and the percentage of apoptotic cell population rose sharply to 90.7 ± 5.1%. These data indicate that MVC apparently exacerbates further killing rather than cytoprotection on this simulated, PQ-intoxicated MDCK cell model and suggest that the treatment of PQ poisoning using MVC protocol should be cautious.

Original languageEnglish
Pages (from-to)991-1001
Number of pages11
JournalFree Radical Research
Volume47
Issue number12
DOIs
Publication statusPublished - Dec 2013

Fingerprint

Paraquat
Ascorbic Acid
Madin Darby Canine Kidney Cells
Oxidative stress
Therapeutics
Cytochromes c
Poisoning
Oxidative Stress
Nonmetals
Cytoprotection
Clinical Protocols
Hydroxyl Radical
Reactive Oxygen Species
Nitric Oxide
Cells
Apoptosis
Safety

Keywords

  • Exacerbated hydroxyl radical production
  • MDCK cells
  • Megadose of vitamin C
  • Non-metal-catalyzed system
  • Paraquat intoxication

ASJC Scopus subject areas

  • Biochemistry

Cite this

Treatment of acute paraquat intoxication using recommended megadose of vitamin C : A reappraisal. / Chang, J. B.; Lin, C. C.; Chiou, J. F.; Mau, S. Y.; Liu, T. Z.; Chen, C. H.

In: Free Radical Research, Vol. 47, No. 12, 12.2013, p. 991-1001.

Research output: Contribution to journalArticle

Chang, J. B. ; Lin, C. C. ; Chiou, J. F. ; Mau, S. Y. ; Liu, T. Z. ; Chen, C. H. / Treatment of acute paraquat intoxication using recommended megadose of vitamin C : A reappraisal. In: Free Radical Research. 2013 ; Vol. 47, No. 12. pp. 991-1001.
@article{f0ea67de2e1e451e9273cdc0d3a0451f,
title = "Treatment of acute paraquat intoxication using recommended megadose of vitamin C: A reappraisal",
abstract = "Megadose of vitamin C (MVC) has been proposed for an emergent treatment of acute paraquat (PQ) poisoning. However, the safety issue of this treatment protocol has not been evaluated. Here, we present the first evidence that vitamin C can promote aggravated production of hydroxyl radical (OH •) via interacting with preexisting PQ+•/H2O2 system in a nonmetal-catalyzed manner. This enhanced oxidative stress would therefore expect to cause more deleterious effect during acute PQ intoxication. To lend support to this possibility, we set out to attest the effects of MVC on a simulated, PQ-intoxicated, Madin-Darby canine kidney (MDCK) cell model. First, PQ alone could trigger oxidative-nitrosative stress (ONS) through robust generation of reactive oxygen species and nitric oxide (NO) that could induce apoptotic killing via promoting effective release of mitochondrial cytochrome c, an apoptogenic factor. The percentage of apoptosis for MDCK cells treated with 1.0 mM PQ for 24 h was 16.3 ± 13.0{\%}. However, when MDCK cells were treated with a combination of PQ (1.0 mM) and MVC (20 mM) for 24 h, the severity of apoptotic killing was further exacerbated as reflected by a nearly 7-fold increase in the release of mitochondrial cytochrome c and the percentage of apoptotic cell population rose sharply to 90.7 ± 5.1{\%}. These data indicate that MVC apparently exacerbates further killing rather than cytoprotection on this simulated, PQ-intoxicated MDCK cell model and suggest that the treatment of PQ poisoning using MVC protocol should be cautious.",
keywords = "Exacerbated hydroxyl radical production, MDCK cells, Megadose of vitamin C, Non-metal-catalyzed system, Paraquat intoxication",
author = "Chang, {J. B.} and Lin, {C. C.} and Chiou, {J. F.} and Mau, {S. Y.} and Liu, {T. Z.} and Chen, {C. H.}",
year = "2013",
month = "12",
doi = "10.3109/10715762.2013.838321",
language = "English",
volume = "47",
pages = "991--1001",
journal = "Free Radical Research",
issn = "1071-5762",
publisher = "Informa Healthcare",
number = "12",

}

TY - JOUR

T1 - Treatment of acute paraquat intoxication using recommended megadose of vitamin C

T2 - A reappraisal

AU - Chang, J. B.

AU - Lin, C. C.

AU - Chiou, J. F.

AU - Mau, S. Y.

AU - Liu, T. Z.

AU - Chen, C. H.

PY - 2013/12

Y1 - 2013/12

N2 - Megadose of vitamin C (MVC) has been proposed for an emergent treatment of acute paraquat (PQ) poisoning. However, the safety issue of this treatment protocol has not been evaluated. Here, we present the first evidence that vitamin C can promote aggravated production of hydroxyl radical (OH •) via interacting with preexisting PQ+•/H2O2 system in a nonmetal-catalyzed manner. This enhanced oxidative stress would therefore expect to cause more deleterious effect during acute PQ intoxication. To lend support to this possibility, we set out to attest the effects of MVC on a simulated, PQ-intoxicated, Madin-Darby canine kidney (MDCK) cell model. First, PQ alone could trigger oxidative-nitrosative stress (ONS) through robust generation of reactive oxygen species and nitric oxide (NO) that could induce apoptotic killing via promoting effective release of mitochondrial cytochrome c, an apoptogenic factor. The percentage of apoptosis for MDCK cells treated with 1.0 mM PQ for 24 h was 16.3 ± 13.0%. However, when MDCK cells were treated with a combination of PQ (1.0 mM) and MVC (20 mM) for 24 h, the severity of apoptotic killing was further exacerbated as reflected by a nearly 7-fold increase in the release of mitochondrial cytochrome c and the percentage of apoptotic cell population rose sharply to 90.7 ± 5.1%. These data indicate that MVC apparently exacerbates further killing rather than cytoprotection on this simulated, PQ-intoxicated MDCK cell model and suggest that the treatment of PQ poisoning using MVC protocol should be cautious.

AB - Megadose of vitamin C (MVC) has been proposed for an emergent treatment of acute paraquat (PQ) poisoning. However, the safety issue of this treatment protocol has not been evaluated. Here, we present the first evidence that vitamin C can promote aggravated production of hydroxyl radical (OH •) via interacting with preexisting PQ+•/H2O2 system in a nonmetal-catalyzed manner. This enhanced oxidative stress would therefore expect to cause more deleterious effect during acute PQ intoxication. To lend support to this possibility, we set out to attest the effects of MVC on a simulated, PQ-intoxicated, Madin-Darby canine kidney (MDCK) cell model. First, PQ alone could trigger oxidative-nitrosative stress (ONS) through robust generation of reactive oxygen species and nitric oxide (NO) that could induce apoptotic killing via promoting effective release of mitochondrial cytochrome c, an apoptogenic factor. The percentage of apoptosis for MDCK cells treated with 1.0 mM PQ for 24 h was 16.3 ± 13.0%. However, when MDCK cells were treated with a combination of PQ (1.0 mM) and MVC (20 mM) for 24 h, the severity of apoptotic killing was further exacerbated as reflected by a nearly 7-fold increase in the release of mitochondrial cytochrome c and the percentage of apoptotic cell population rose sharply to 90.7 ± 5.1%. These data indicate that MVC apparently exacerbates further killing rather than cytoprotection on this simulated, PQ-intoxicated MDCK cell model and suggest that the treatment of PQ poisoning using MVC protocol should be cautious.

KW - Exacerbated hydroxyl radical production

KW - MDCK cells

KW - Megadose of vitamin C

KW - Non-metal-catalyzed system

KW - Paraquat intoxication

UR - http://www.scopus.com/inward/record.url?scp=84887454630&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84887454630&partnerID=8YFLogxK

U2 - 10.3109/10715762.2013.838321

DO - 10.3109/10715762.2013.838321

M3 - Article

VL - 47

SP - 991

EP - 1001

JO - Free Radical Research

JF - Free Radical Research

SN - 1071-5762

IS - 12

ER -