The water disinfectant byproduct dibromoacetonitrile induces apoptosis in rat intestinal epithelial cells

Possible role of redox imbalance

Sam Jacob, Bhupendra Kaphalia, Nissi Jacob, Ahmed E. Ahmed

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Chemically induced oxidative stress poses cytotoxic effects on intestinal epithelial cells that may trigger various forms of injuries in intestinal mucosa. Haloacetonitriles, including dibromoacetonitrile (DBAN, a drinking water contaminant and direct acting mutagen and carcinogen), are known to induce GI disorders. Earlier, we showed that dichloroacetonitrile (DBAN analog) alters glutathione status and increases reactive oxygen species in murine macrophage cell line. Therefore, the present study was undertaken to understand the role of redox imbalance and apoptosis in DBAN-induced GI disorders using rat intestinal epithelial (RIE) cells. Cultured confluent monolayers of RIE cells were continuously exposed to DBAN at 50 to 400 ppb (0.6 to 4.4 μM). After 24, 48, and 72 h of the exposure, oxidative stress and apoptosis were determined. At higher exposure regimens (100 to 400 ppb), a concentration- and time-dependent increase in glutathione disulfide levels (1.5 to 4-fold and 1.6 to 5-fold, p < 0.05) was noticed at 48 and 72 h, respectively, as compared to control. Severe depletion of reduced glutathione was also observed at 72 h after DBAN treatment. DBAN-induced oxidative stress was demonstrated at all concentrations by increased malondialdehyde (MDA) levels (1.3 to 3- and 1.8 to 4-fold, p < 0.05) at 48 and 72 h after treatment, respectively. Increase (1.3 to 2-fold, p < 0.05) in 8-hydroxy-2-deoxyguanosine (8OHdG) levels was observed at 48 h after treatment with 100-400 ppb DBAN. At 72 h these levels were 1.7 to 3-fold higher in DBAN-treated RIE cells as compared to control. DBAN-induced apoptosis, evaluated using TUNEL assay and differential staining techniques, indicates an increase in nuclear damage along with various apoptotic features using epifluorescence or light microscopy. The results of the present study suggest that DBAN-induced redox unbalance could lead to apoptosis and overall oxidative stress in RIE cells.

Original languageEnglish (US)
Pages (from-to)227-234
Number of pages8
JournalToxicology Mechanisms and Methods
Volume16
Issue number4
DOIs
StatePublished - May 2006

Fingerprint

dibromoacetonitrile
Disinfectants
Oxidative stress
Oxidation-Reduction
Byproducts
Rats
Epithelial Cells
Apoptosis
Oxidative Stress
Water
Glutathione
Glutathione Disulfide
Macrophages
In Situ Nick-End Labeling
Mutagens
Intestinal Mucosa
Malondialdehyde
Drinking Water
Carcinogens
Optical microscopy

Keywords

  • Apoptosis
  • Dibromoacetonitrile
  • Intestinal Epithelium
  • Oxidative Stress
  • Redox Imbalance
  • Water Disinfectant Byproducts

ASJC Scopus subject areas

  • Toxicology
  • Health, Toxicology and Mutagenesis

Cite this

The water disinfectant byproduct dibromoacetonitrile induces apoptosis in rat intestinal epithelial cells : Possible role of redox imbalance. / Jacob, Sam; Kaphalia, Bhupendra; Jacob, Nissi; Ahmed, Ahmed E.

In: Toxicology Mechanisms and Methods, Vol. 16, No. 4, 05.2006, p. 227-234.

Research output: Contribution to journalArticle

@article{f7a1f4170d7747aebf842bc175f204c4,
title = "The water disinfectant byproduct dibromoacetonitrile induces apoptosis in rat intestinal epithelial cells: Possible role of redox imbalance",
abstract = "Chemically induced oxidative stress poses cytotoxic effects on intestinal epithelial cells that may trigger various forms of injuries in intestinal mucosa. Haloacetonitriles, including dibromoacetonitrile (DBAN, a drinking water contaminant and direct acting mutagen and carcinogen), are known to induce GI disorders. Earlier, we showed that dichloroacetonitrile (DBAN analog) alters glutathione status and increases reactive oxygen species in murine macrophage cell line. Therefore, the present study was undertaken to understand the role of redox imbalance and apoptosis in DBAN-induced GI disorders using rat intestinal epithelial (RIE) cells. Cultured confluent monolayers of RIE cells were continuously exposed to DBAN at 50 to 400 ppb (0.6 to 4.4 μM). After 24, 48, and 72 h of the exposure, oxidative stress and apoptosis were determined. At higher exposure regimens (100 to 400 ppb), a concentration- and time-dependent increase in glutathione disulfide levels (1.5 to 4-fold and 1.6 to 5-fold, p < 0.05) was noticed at 48 and 72 h, respectively, as compared to control. Severe depletion of reduced glutathione was also observed at 72 h after DBAN treatment. DBAN-induced oxidative stress was demonstrated at all concentrations by increased malondialdehyde (MDA) levels (1.3 to 3- and 1.8 to 4-fold, p < 0.05) at 48 and 72 h after treatment, respectively. Increase (1.3 to 2-fold, p < 0.05) in 8-hydroxy-2-deoxyguanosine (8OHdG) levels was observed at 48 h after treatment with 100-400 ppb DBAN. At 72 h these levels were 1.7 to 3-fold higher in DBAN-treated RIE cells as compared to control. DBAN-induced apoptosis, evaluated using TUNEL assay and differential staining techniques, indicates an increase in nuclear damage along with various apoptotic features using epifluorescence or light microscopy. The results of the present study suggest that DBAN-induced redox unbalance could lead to apoptosis and overall oxidative stress in RIE cells.",
keywords = "Apoptosis, Dibromoacetonitrile, Intestinal Epithelium, Oxidative Stress, Redox Imbalance, Water Disinfectant Byproducts",
author = "Sam Jacob and Bhupendra Kaphalia and Nissi Jacob and Ahmed, {Ahmed E.}",
year = "2006",
month = "5",
doi = "10.1080/15376520600626239",
language = "English (US)",
volume = "16",
pages = "227--234",
journal = "Toxicology Mechanisms and Methods",
issn = "1537-6516",
publisher = "Informa Healthcare",
number = "4",

}

TY - JOUR

T1 - The water disinfectant byproduct dibromoacetonitrile induces apoptosis in rat intestinal epithelial cells

T2 - Possible role of redox imbalance

AU - Jacob, Sam

AU - Kaphalia, Bhupendra

AU - Jacob, Nissi

AU - Ahmed, Ahmed E.

PY - 2006/5

Y1 - 2006/5

N2 - Chemically induced oxidative stress poses cytotoxic effects on intestinal epithelial cells that may trigger various forms of injuries in intestinal mucosa. Haloacetonitriles, including dibromoacetonitrile (DBAN, a drinking water contaminant and direct acting mutagen and carcinogen), are known to induce GI disorders. Earlier, we showed that dichloroacetonitrile (DBAN analog) alters glutathione status and increases reactive oxygen species in murine macrophage cell line. Therefore, the present study was undertaken to understand the role of redox imbalance and apoptosis in DBAN-induced GI disorders using rat intestinal epithelial (RIE) cells. Cultured confluent monolayers of RIE cells were continuously exposed to DBAN at 50 to 400 ppb (0.6 to 4.4 μM). After 24, 48, and 72 h of the exposure, oxidative stress and apoptosis were determined. At higher exposure regimens (100 to 400 ppb), a concentration- and time-dependent increase in glutathione disulfide levels (1.5 to 4-fold and 1.6 to 5-fold, p < 0.05) was noticed at 48 and 72 h, respectively, as compared to control. Severe depletion of reduced glutathione was also observed at 72 h after DBAN treatment. DBAN-induced oxidative stress was demonstrated at all concentrations by increased malondialdehyde (MDA) levels (1.3 to 3- and 1.8 to 4-fold, p < 0.05) at 48 and 72 h after treatment, respectively. Increase (1.3 to 2-fold, p < 0.05) in 8-hydroxy-2-deoxyguanosine (8OHdG) levels was observed at 48 h after treatment with 100-400 ppb DBAN. At 72 h these levels were 1.7 to 3-fold higher in DBAN-treated RIE cells as compared to control. DBAN-induced apoptosis, evaluated using TUNEL assay and differential staining techniques, indicates an increase in nuclear damage along with various apoptotic features using epifluorescence or light microscopy. The results of the present study suggest that DBAN-induced redox unbalance could lead to apoptosis and overall oxidative stress in RIE cells.

AB - Chemically induced oxidative stress poses cytotoxic effects on intestinal epithelial cells that may trigger various forms of injuries in intestinal mucosa. Haloacetonitriles, including dibromoacetonitrile (DBAN, a drinking water contaminant and direct acting mutagen and carcinogen), are known to induce GI disorders. Earlier, we showed that dichloroacetonitrile (DBAN analog) alters glutathione status and increases reactive oxygen species in murine macrophage cell line. Therefore, the present study was undertaken to understand the role of redox imbalance and apoptosis in DBAN-induced GI disorders using rat intestinal epithelial (RIE) cells. Cultured confluent monolayers of RIE cells were continuously exposed to DBAN at 50 to 400 ppb (0.6 to 4.4 μM). After 24, 48, and 72 h of the exposure, oxidative stress and apoptosis were determined. At higher exposure regimens (100 to 400 ppb), a concentration- and time-dependent increase in glutathione disulfide levels (1.5 to 4-fold and 1.6 to 5-fold, p < 0.05) was noticed at 48 and 72 h, respectively, as compared to control. Severe depletion of reduced glutathione was also observed at 72 h after DBAN treatment. DBAN-induced oxidative stress was demonstrated at all concentrations by increased malondialdehyde (MDA) levels (1.3 to 3- and 1.8 to 4-fold, p < 0.05) at 48 and 72 h after treatment, respectively. Increase (1.3 to 2-fold, p < 0.05) in 8-hydroxy-2-deoxyguanosine (8OHdG) levels was observed at 48 h after treatment with 100-400 ppb DBAN. At 72 h these levels were 1.7 to 3-fold higher in DBAN-treated RIE cells as compared to control. DBAN-induced apoptosis, evaluated using TUNEL assay and differential staining techniques, indicates an increase in nuclear damage along with various apoptotic features using epifluorescence or light microscopy. The results of the present study suggest that DBAN-induced redox unbalance could lead to apoptosis and overall oxidative stress in RIE cells.

KW - Apoptosis

KW - Dibromoacetonitrile

KW - Intestinal Epithelium

KW - Oxidative Stress

KW - Redox Imbalance

KW - Water Disinfectant Byproducts

UR - http://www.scopus.com/inward/record.url?scp=33646350542&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33646350542&partnerID=8YFLogxK

U2 - 10.1080/15376520600626239

DO - 10.1080/15376520600626239

M3 - Article

VL - 16

SP - 227

EP - 234

JO - Toxicology Mechanisms and Methods

JF - Toxicology Mechanisms and Methods

SN - 1537-6516

IS - 4

ER -