Toxicity Assessment of Long-Term Exposure to Non-Thermal Plasma Activated Water in Mice

Abstract

Non-thermal plasma activated water (PAW) has recently emerged as a powerful antimicrobial agent. Despite numerous potential bio-medical applications, studies concerning toxicity in live animals, especially after long-term exposure, are scarce. Our study aimed to assess the effects of long-term watering with PAW on the health of CD1 mice. PAW was prepared from distilled water with a GlidArc reactor according to a previously published protocol. The pH was 2.78. The mice received PAW (experimental group) or tap water (control group) daily for 90 days as the sole water source. After 90 days, the following investigations were performed on the euthanatized animals: gross necropsy, teeth mineral composition, histopathology, immunohistochemistry, hematology, blood biochemistry, methemoglobin level and cytokine profile. Mice tolerated PAW very well and no adverse effects were observed during the entire period of the experiment. Histopathological examination of the organs and tissues did not reveal any structural changes. Moreover, the expression of proliferation markers PCNA and Ki67 has not been identified in the epithelium of the upper digestive tract, indicating the absence of any pre- or neoplastic transformations. The results of our study demonstrated that long-term exposure to PAW caused no toxic effects and could be used as oral antiseptic solution in dental medicine.

Applications of Plasma-Activated Water in Dentistry: A Review

“…The authors observed that there were not significant changes in the mineral composition and surface micro-morphology of the teeth. Moreover, the long-term exposure was not toxic to the tongue, oral mucosa, sublingual glands or other body organs, which presented normal structure and physiology [132]. In addition to not being harmful to mammalian cells, NTAPPs have been demonstrated to decrease inflammation and contribute to tissue repair [133].…”

Preclinical Cold Atmospheric Plasma Cancer Treatment

“…PAS selectively kills colon, lung, cervical, bladder, melanoma, and breast cancer cells in vitro [ 76 , 77 , 78 , 79 , 80 ]. Preliminary studies on immuno-deficient nude mice by oral lavage treatment of CAP-activated water did not find lethal effects and acute toxicity [ 81 , 82 ]. Furthermore, the mice had no significant changes, including body weight, survival status, organ coefficient, function, and tissue structure of heart, liver, spleen, lung, and kidney [ 81 , 82 ].…”

The effect of plasma‐activated water in a mouse model of inflammatory bowel disease

“…A recent study has shown the effects of long‐term (90 days) watering with PAW on the health of mice. [ 39 ] This is the only available study examining the intraoral administration of PAW. The authors conclude that the mice tolerated PAW very well, and PAW had no hematological, biochemical, or immunological effects in the blood and no histopathological effects on tissues throughout the body, including the colon.…”