Drug Discov Ther. 2023;17(6):404-408. (DOI: 10.5582/ddt.2023.01080)

Single intratracheal administration toxicity study on safety of vapor inhalation of electrolyzed reduced water in rats

Wada YI, Okajima Y, Oshima Y, Shimokawa K, Okajima M, Ishii F

The effects of acute intratracheal administration of electrolyzed reduced water (ERW; alkaline electrolyzed water) were investigated in rats. In this study, no deaths or near-deaths were recorded in either group, namely those treated with ERW or purified water (maximum doses of 900 mg/kg). The main symptoms observed in the rats were decreased spontaneous movements and abnormal breath sounds, which were considered to be transient symptoms caused by intratracheal administration. In addition, low values of alkaline phosphatase, total protein and lactate dehydrogenase were found in BALF tests, but these values were considered to be of low toxicological significance, since they are usually high in the presence of lung inflammation or cellular damage. This suggests that the alkalinity of ERW partially contributes to broken peptide bonds in proteins. There were no significant increases in bronchoalveolar lavage fluid protein in either group. ERW did not cause an increase in the influx of neutrophils, eosinophils, basophils, or lymphocytes, suggesting that intratracheal administration of ERW did not cause lung inflammation. ERW did not cause abnormalities in the body or pathological changes in the lungs. Aggregates of alveolar macrophages, as a measure of inflammation, were observed in both groups. These may be transient symptoms due to intratracheal administration, not due to ERW toxicity. This study confirmed the safety of intratracheal ERW infusion and demonstrated the low risk of acute toxicity for inhalation exposure to ERW aerosol or vapor. Therefore, ERW may be an effective air purifier against viruses or bacteria.

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