Effect of terahertz radiation on drug activity in bacterial cells

Abstract

Terahertz (THz) waves have been reported to change membrane permeability and induce conformational changes in protein molecules. Drugs action on cells involves membrane permeability, and we therefore investigated the effect of THz waves on the activity of the cytotoxic drug bleomycin on Escherichia coli. 0.46 THz radiation with an average power of 2.5 W/cm² was noncytotoxic to E. coli cells. However, 0.46 THz radiation enhanced the cytotoxic activity of bleomycin in E. coli cells, and the drug-enhancing effect depended on the power density of the THz waves. Then, the activity of the drug remaining in the culture medium after THz radiation did not differ from that remaining after non-radiation. This indicates that THz radiation does not affect the bacterial cell-membrane permeability to bleomycin. Thus, these results suggest that 0.46 THz radiation enhances the cytotoxicity of bleomycin to E. coli cells and may influence the mechanism of bleomycin action within cells rather than affecting drug uptake.

KEYWORDS:

• Terahertz radiation
• bacterial cell
• antitumor antibiotic
• bleomycin

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by JSPS Grant-in Aid for Scientific Research (C) under Grants 22K04214 and 22K12763.