Evaluation of the toxic effect of the herbicide 2, 4-D on rat hepatocytes: an FT-IR spectroscopic study.

Abstract

Infrared spectroscopy is a powerful technique used to investigate molecular structures to the level of bond lengths and angles. In this study, the hepatotoxic effect of 2, 4-dichlorophenoxyacetic acid (2, 4-D) was investigated using Fourier transform infrared (FT-IR) spectroscopy. The experiment was performed on 15 male albino Wister rats (250-350g) divided randomly into a control group (5 rats) and 2, 4-D-treated group (10 rats). The 2, 4-D-treated group received a single oral gavage LD50 dose of 639mg/kg body weight; the rats were then killed and the livers excised 24h after 2, 4-D administration. Spectroscopic results revealed that there was a significant reduction in protein content as well as a marked decrease in the secondary structure of protein after 2, 4-D intoxication. Moreover, looseness of membrane lipid chain packing, lipid polarity and/or significant increases in the formation of lipids with hydroperoxyl groups and carbonyl compounds were shown in the 2, 4-D LD50-treated group compared to the control group. Glycogen is dramatically decreased in rat liver after the induction of 2, 4-D. In conclusion, FTIR spectroscopy proved to be a rapid and sensitive approach to cytotoxicity diagnosis and monitoring of toxin-induced damage in biological membranes and proteins. In addition, the FTIR parameters employed in this study can be used as biophysical indicators of toxin-induced cell or membrane damage during apoptosis.