The Anti-Inflammatory Activity of No-Ozone Cold Plasma Can Be Delivered Through a Conductive Metal Needle on TNFα-Treated C2C12 Mice Muscle Cells In Vitro

Recently, an anti-inflammatory effect of no-ozone cold plasma (NCP) has been reported, but the direct use of NCP for treating muscle inflammation is very difficult since NCP is a form of gas. In this study, we tested whether the anti-inflammatory effect of the NCP could be delivered through conductive metal needles to reduce muscle inflammation. C2C12 mouse muscle cells were treated with TNFα to induce muscle inflammation and then treated with NCP and a conductive metal needle separately or in combination. The effects of NCP and a needle were monitored by performing RT‒PCR and Western blot analysis. As a result, NCP effectively suppressed the TNFα-mediated expression of the TNFα, IL1β, and FasL genes, but this effect weakened as the distance between the cells and the NCP increased. On the other hand, treatment of cells with a plasma-needle (PN) had an anti-inflammatory effect regardless of distance, and the anti-inflammatory effect of the PN was maintained under conditions where the gas flow of NCP was not delivered to the cells. It is believed that the PN-mediated activation of media plays a pivotal role in the anti-inflammatory effect of the PN. Finally, this study also showed that electroacupuncture can inhibit TNFα-induced inflammatory gene expression in a manner like a PN. Taken together, the results of this study demonstrate that the anti-inflammatory effect of NCP can be delivered through metal needles, suggesting that PN may be useful for treating inflammatory muscle pain.