Suppression of Airway Allergic Reactions by a Photocatalytic Filter Using Mouse Model.

Taisuke Tomonaga,Etsushi Kuroda,Kazuhiro Yatera,Chinatsu Nishida,Kaori Kato,Yasuo Morimoto,Hiroto Izumi

doi:10.3390/toxics10010040

Taisuke Tomonaga, Etsushi Kuroda + Show 5 more

Open Access

https://doi.org/10.3390/toxics10010040

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Abstract

Photocatalytic filters installed in air purifiers have been used to purify spaces by decomposing allergenic substances. However, we have not found any reports that evaluate the effectiveness of photocatalytic filters in suppressing allergic reactions in living organisms. In this study, we intratracheally instilled ovalbumin (OVA) into OVA-sensitized mice after the OVA was photocatalyzed by a titanium dioxide (TiO2) filter, and verified the experimental model for evaluating the allergy-suppressing effect of photocatalysts. Mice were sensitized to OVA (10 µg/mouse) four times, and were intratracheally instilled with OVA (10 µg/mouse) after photocatalysis three times. Non-sensitized animals were instilled with normal saline following the same exposure schedule. The mice were dissected 24 h after final exposure. The OVA after photocatalysis significantly decreased the number of eosinophils in bronchoalveolar lavage fluid, and the concentration of OVA-specific IgE and IgG1 in serum, which were elevated in untreated OVA. Moreover, our experimental model showed the suppression of allergic reactions in mice, along with the decomposition of OVA after photocatalysis using the photocatalytic filter. Taken together, our experimental model for evaluating allergic reactions in the respiratory tract suggested that the allergy-suppressing effect of the photocatalytic filter can be evaluated.

Highlights

In recent years, environmental policies have become an inevitable and important issue from the perspective of sustainable development, and various environmental policies are being implemented in various countries [1,2,3]
Air pollution caused by fine particulate matter (PM2.5), volatile organic compounds (VOCs), and bioaerosols has been recognized as an environmental risk with adverse health effects [4,5,6,7]
We conducted intratracheal instillation into mice using OVA after photocatalysis in the presence of a TiO2 filter produced by LT-HOVF spraying, in order to verify the suppression of the allergic reaction by the photocatalytic filter

Summary

Introduction

Environmental policies have become an inevitable and important issue from the perspective of sustainable development, and various environmental policies are being implemented in various countries [1,2,3]. Air pollution caused by fine particulate matter (PM2.5), volatile organic compounds (VOCs), and bioaerosols has been recognized as an environmental risk with adverse health effects [4,5,6,7]. These air pollutants are known to cause allergic diseases, such as asthma and allergic rhinitis, due to their involvement in airway inflammation, airway hyperresponsiveness symptoms, and allergic sensitization due to trans-airway exposure [6,8].

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