During the last decade there has been a remarkable and unexplained increase in the prevalence of asthma. These studies were conducted to investigate the role of dermal exposure to triclosan, an endocrine-disrupting compound, on the hypersensitivity response to ovalbumin (OVA) in a murine model of asthma. Triclosan has had widespread use in the general population as an antibacterial and antifungal agent and is commonly found in consumer products such as soaps, deodorants, toothpastes, shaving creams, mouth washes, and cleaning supplies. For these studies, BALB/c mice were exposed dermally to concentrations of triclosan ranging from 0.75-3% (0.375-1.5 mg/mouse/day) for 28 consecutive days. Concordantly, mice were intraperitoneally injected with OVA (0.9 ug) and aluminum hydroxide (0.5 mg) on days 1 and 10 and challenged with OVA (125 ug) by pharyngeal aspiration on days 19 and 27. Compared to the animals exposed to OVA alone, increased spleen weights, OVA-specific IgE, Interleukin (IL)-13 cytokine levels, and lung eosinophils were demonstrated when mice were co-exposed to OVA and triclosan. Statistically significant increases in OVA-specific and non-specific airway hyperreactivity (AHR) were observed for all triclosan co-exposed groups when compared to the vehicle and OVA controls. In these studies exposure to triclosan alone was not demonstrated to be allergenic, however co-exposure with a known allergen resulted in enhancement of the hypersensitivity response to that allergen, suggesting that triclosan exposure may augment the allergic responses to other environmental allergens.
Toxicology; Bronchial-asthma; Laboratory-animals; Laboratory-techniques; Exposure-assessment; Exposure-levels; Pulmonary-function; Pulmonary-system-disorders; Lung-function; Dose-response; Lung-disorders; Lung-irritants; Respiratory-system-disorders; Skin-exposure; Endocrine-function; Endocrine-system; Hypersensitivity; Antibacterial-agents; Antifungals; Aluminum-compounds; Lung-cells; Allergens; Allergic-reactions; Analytical-models; Animal-studies; Laboratory-testing; Hypersensitivity; Cytotoxic-effects; Lung-irritants; Airway-resistance
The Toxicologist. Society of Toxicology 52nd Annual Meeting and ToxExpo, San Antonio, Texas, March 10-14, 2013