Genotoxic Effect of Arsenic and Its Amelioration by Zinc and Selenium Administered Singly and Synergistically in Female Albino Rats

Abstract

Arsenic is a ubiquitous environmental toxicant present in food, soil, water, and air, and is released into the environment from anthropogenic and man-made sources. The major inorganic forms of arsenic are arsenite and arsenate, while arsenite is more cytotoxic and genotoxic than arsenate. The study was to determine the extent of DNA damage by the ingestion of arsenic (in arsenic trioxide form) in the drinking water of female albino rats at varying concentrations and the ameliorative effect of zinc and selenium on the ingested arsenic trioxide. 90 female Wistar albino rats, 141.5 ± 3.68 g were randomized into 9 groups of 10 rats each and used for this study. The control groups were as follows: no treatment, 50mg/kg of Zn, and 200µg/kg of Se, while the treatment groups were: 20ppm of As, 50ppm of As, 100ppm of As, 200µg/kg of Se + 100ppm of As, 50mg/kg of Zn + 100ppm of As, and 200µg/kg of Se + 50mg/kg of Zn + 100ppm of As. DNA damage and the ameliorative effect of the supplements were assessed using Comet assays. DNA damage increased in the groups administered arsenic in this order: 20ppm < 50ppm < 100ppm. Significant DNA damage was observed in the group administered 100ppm of As (p<0.05), making arsenic a potent carcinogen. Group administered 100ppm As + 200µg/kg Se + 50 mg/kg Zn did not show any significant DNA damage. Oral administration of zinc and selenium was an excellent ameliorative agent both individually and synergistically on the genotoxic effect (carcinogenicity) of arsenic trioxide.