Use of ozonated water as a new therapeutic approach to anti-tumor treatment

Background

Tumours often contain regions with very low oxygen levels, a state known as hypoxia. Hypoxic tumour tissue is notoriously resistant to chemotherapy and radiotherapy, partly because oxygen is needed for many of these treatments to generate the cell damage that kills cancer cells. Poor blood flow within a tumour is one of the main drivers of this low-oxygen environment. Researchers in Japan investigated whether ozonated water - water that has had ozone gas dissolved into it - could improve blood flow and oxygen supply inside tumours, and whether this might make an existing chemotherapy drug work more effectively.

Study design

The study was conducted in mice. Colon26 mouse colorectal cancer cells were injected under the skin of female BALB/c mice to create tumours. Once tumours had formed, the researchers administered ozonated water into the abdominal cavity and measured its effects using several methods: a polarographic electrode to record oxygen pressure inside the tumour, a fluorescent dye (Hoechst 33342) to visualise blood perfusion, Ki-67 staining to assess cell proliferation, and TUNEL staining to detect cell death. In a second phase, groups of five to eight mice received ozonated water combined with the chemotherapy drug cisplatin at different doses, and tumour growth was tracked over time and compared with cisplatin used alone.

Findings

Ozonated water significantly increased oxygen pressure inside the tumours within around 20 minutes of administration, with levels peaking at about 50 minutes. Blood perfusion also improved: the proportion of tumour tissue showing dye uptake, indicating blood flow, rose from around 12% in untreated tumours to around 26% in tumours treated with ozonated water. When ozonated water was combined with cisplatin, tumour growth was suppressed more than with cisplatin alone, cell proliferation markers were lower, and markers of cell death were higher. A lower dose of cisplatin combined with ozonated water achieved tumour suppression comparable to a higher dose of cisplatin used on its own.

What the authors concluded

The authors concluded that ozonated water improved blood perfusion and reduced hypoxia inside tumours, and that this effect enhanced the anti-tumour activity of cisplatin. They suggested that ozonated water could offer a way to address two long-standing problems in cancer treatment - tumour hypoxia and drug resistance - and that it might allow lower chemotherapy doses to achieve a similar effect.

Limitations of this study

This was a preclinical study conducted in mice with an implanted colon cancer cell line, not in humans, so the results cannot be assumed to translate directly to human cancer patients. Group sizes were small (five to eight animals), only one chemotherapy drug and one tumour model were tested, and longer-term outcomes such as survival were not reported. The precise mechanism by which ozonated water improved blood perfusion was also not fully established. This study concerns the effect of ozonated water on tumour oxygenation and chemotherapy response in a mouse model. It does not establish ozone as a treatment or cure for cancer itself. Ozone therapy is a complementary approach and should always be discussed with your oncology team.