Evaluation of Buccal Damage Associated with Acute Inhalation Exposure to 2,4-Dichlorophenoxyacetic Acid (2,4-D) in Mice

Abstract

Background: The herbicide dichlorophenoxyacetic acid (2,4-D) is one of the most widely used crop spraying products in the world. Some pesticides induce the degranulation of mast cells and increase allergic responses. This is the first study to evaluate the damage to the oral mucosa after an experimental simulation of environmental inhalation exposure to the 2,4-D herbicide. The aim of this study was evaluate the possible oral damage caused by acute inhalation exposure to the herbicide 2,4-D.Methods: A total of 80 Swiss male mice were divided into 4 groups (n = 20) and evaluated at different time intervals (24 h, 48 h, 72 h and 8 days), with 5 animals / period. The animals were divided into the following groups: SG: nebulization with sodium chloride solution; LCG: pesticide nebulization with 3.71 x 10-3 grams of active ingredient per hectare (g.i.a. / ha); MCG: pesticide nebulization with 6.19 x 10-3 g.i.a. /ha; and HCG: pesticide nebulization with 9.28 x 10-3 g.i.a. /ha. The tongues of the mice were collected for histopathological analysis.Results: There was a difference between the exposure concentrations in relation to tissue congestion intensity (p = 0.002) and mast cell counts (p = 0.002), a difference in the evaluation of the interaction between the exposure concentrations and nebulization time in the dorsum epithelium thickness (p = 0.013), and a significant correlation between the epithelial thickness and the number of nucleoli organizing regions on the dorsum of the tongue (p = 0.048).Conclusions: Even after acute exposure, the herbicide 2,4-D had the potential to damage the oral epithelium, especially at higher doses.