In Vivo Effects of Acute Permethrin Exposure on Sinonasal Epithelia in a Murine Model

Background: Environmental exposures, including airborne pollutants and toxicants have been postulated to contribute to the pathogenesis of chronic rhinosinusitis (CRS). Residential proximity to commercial pesticide application has been reported to increase the risk of CRS by 4.8-fold. Permethrin is a widely used pesticide in agricultural and military settings. In a recent in vitro study, permethrin exposure was found to be cytotoxic to cultured sinonasal epithelial cells, reducing cellular proliferation and viability in a dose-dependent manner. However, the effects of permethrin on sinonasal tissue in vivo have yet to be explored.

Objective: The purpose of this study is to investigate the acute effects of Permethrin exposure on sinonasal epithelia utilizing an in vivo murine experimental model.

Methods: This study was approved by Institutional Animal Care and Use Committee (IACUC). Sixteen mice were exposed for a 2-week period transnasally to solutions containing either saline/50% Dimethylsulfoxide (controls, n = 4) or various concentrations of permethrin (150 mg/kg/d: n = 6,300 mg/kg/d: n = 6) dissolved in 50% DSMO). Sinonasal tissue was harvested after the exposure period and histopathologic analysis performed.

Results: Ten of the 12 exposed mice demonstrated signs of inflammation after the 2-week period of Permethrin exposure. Hematoxylin and eosin stains of sinus tissues in experimental mice showed increased mucinous cells in the stroma, extravasated mucinous material, neutrophilic infiltration, and/or lymphocytic infiltration. One of the exposed mice showed no evidence of inflammation. The other sample was damaged during tissue processing and could not be evaluated. All four control mice showed no evidence of inflammation.

Conclusion: This pilot study is the first to demonstrate the acute effects of Permethrin on sinonasal epithelia in vivo. Short-term intranasal exposures induced inflammatory changes including neutrophilic and lymphocytic infiltration as well as increased mucinous cells in the underlying stroma compared with controls. These findings indicate that acute exposure to Permethrin has a proinflammatory impact on sinonasal epithelia.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
07 February 2025