The Effects of Plasma-Activated Saline and Medium on Colorectal Cancer in Rat Models and the Human Colon Adenocarcinoma Cell Line COLO 205

Abstract

Colorectal cancer affects a large number of people. There is an urgent need to develop novel treatments for this disease. In recent years, research on medical applications of atmospheric low temperature plasma (ALTP) has been actively conducted, and cancer treatment is one of the targets. In this study, we focused on colorectal cancer and evaluated plasma as a new treatment method. In vivo and in vitro experiments were conducted using plasma-treated saline (PTS) and plasma-treated medium (PTM) prepared by submerged bubbling treatment using ALTP. In vivo experiments using a rat model of colorectal cancer revealed that PTS administration to the colon slowed tumor progression based on endoscopic and histopathological observations. To investigate the cause of the inhibition of tumor progression, we evaluated the impact of ALTP on colon cancer cells. As a result of culturing colorectal cancer cells with PTM, cell proliferation was inhibited. Also, cell death was induced by cell swelling. qPCR revealed that PTMs induced cell death of cancer cells through signaling of tumor necrosis factor α (TNF-α), an inflammatory cytokine. Therefore, the inhibition of cancer progression by PTS in the rat model occurs by inducing cell death through the dissolution of ALTP components in the liquid.