The effect of arsenic exposure and the efficacy of DMSA on the proteins and lipids of the gill tissues of Labeo rohita

Arsenic is a naturally occurring, highly toxic environmental pollutant. Fourier transform infrared (FT-IR) spectroscopy is a non-disturbing technique which provides quantitative information about the molecular composition of biological samples. The aim of this work is to study the compositional and structural changes at the molecular level occurring in gill tissues of Labeo rohita fingerlings due to arsenic exposure for various exposure periods by using FT-IR spectroscopic technique. The results of the present study suggest that arsenic exposure causes significant changes on the major biochemical constituents such as proteins, lipids and nucleic acids in the gill tissues of L. rohita. The changes are more pronounced as the period of exposure is increased. The significant decrease in the intensity and area of the amide I peak and CH₃ asymmetric stretching band suggests an alteration in the protein profile and lipid levels respectively, due to arsenic exposure. The amide A peak shifts suggests a change in the level of protein amide hydrogen bonding due to arsenic exposure. Further, the treatment with meso-2,3-dimercaptosuccinic acid (DMSA) improves the levels of biochemical constituents significantly, which suggest that DMSA treatment reduces the toxic effects and helps the recovery of gill tissues and its return to the level of the control.