Imidacloprid induced histomorphological changes and expression of TLR-4 and TNFα in lung

Abstract

The imidacloprid is used worldwide as a pesticide and has been linked with endocrine disturbances and reduced pulmonary function. However, effects of imidacloprid alone or in combination with microbial molecules on lungs are not fully understood. Because the pulmonary effects of interactions of endotoxins with imidacloprid are unknown, we designed a study to investigate that in a mouse model. Mice (N=14) were given imidacloprid orally @ 1/20th of LD50 dissolved in corn oil for 30days. After the treatments, six animals from each group were challenged with E. coli lipopolysaccharide (LPS) @ 80μg/animal via intranasal route and remaining animals were challenged with normal saline solution @ 80μl/animal via same route. Imidacloprid in combination with LPS led to significant increase in total cell and neutrophil counts in BAL and peripheral blood. Semi-quantitative histopathology revealed lung injury in imidacloprid treatment group and injury was more marked in animal receiving both imidacloprid and LPS. There was no change (p<0.05) in the expression of TLR-4 and TNF-α both at mRNA and protein levels following exposure to imidacloprid alone or in combination with LPS. The data show that imidacloprid alone or in combination with LPS resulted changes in lung morphology without altering the expression of TLR-4 and TNF-α. Furthermore, pre-treatment with imidacloprid didn't affect response to LPS.