title: Acute oral dose of sodium nitrite induces redox imbalance, DNA damage, metabolic and histological changes in rat intestine.
abstract: Industrialization and unchecked use of nitrate/nitrite salts for various purposes has increased human exposure to high levels of sodium nitrite (NaNO2) which can act as a pro-oxidant and pro-carcinogen. Oral exposure makes the gastrointestinal tract particularly susceptible to nitrite toxicity. In this work, the effect of administration of a single acute oral dose of NaNO2 on rat intestine was studied. Animals were randomly divided into four groups and given single doses of 20, 40, 60 and 75 mg NaNO2/kg body weight. Untreated animals served as the control group. An NaNO2 dose-dependent decline in the activities of brush border membrane enzymes, increase in lipid peroxidation, protein oxidation, hydrogen peroxide levels and decreased thiol content was observed in all treated groups. The activities of various metabolic and antioxidant defense enzymes were also altered. NaNO2 induced a dose-dependent increase in DNA damage and DNA-protein crosslinking. Histopathological studies showed marked morphological damage in intestinal cells. The intestinal damage might be due to nitrite-induced oxidative stress, direct action of nitrite anion or chemical modification by reaction intermediates.
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India.
authors.forename: Fariheen Aisha
authors.initials: FA
authors.lastname: Ansari
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India.
authors.forename: Shaikh Nisar
authors.initials: SN
authors.lastname: Ali
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India.
authors.forename: Hussain
authors.initials: H
authors.lastname: Arif
authors.affiliation: Department of Anatomy, Faculty of Medicine, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh, India.
authors.forename: Aijaz Ahmed
authors.initials: AA
authors.lastname: Khan
authors.affiliation: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh, India.
authors.forename: Riaz
authors.initials: R
authors.lastname: Mahmood
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000187:drug effects* / Q000473:pathology; D015227:Lipid Peroxidation; D008297:Male; D010084:Oxidation-Reduction; D051381:Rats; D017208:Rats, Wistar; D012977:Sodium Nitrite / Q000008:administration & dosage*; D013438:Sulfhydryl Compounds / Q000378:metabolism
chemical_list: D013438:Sulfhydryl Compounds; D006861:Hydrogen Peroxide; D005978:Glutathione; D012977:Sodium Nitrite